where, p is the number of current iteration; VT - complete metal sliding speed on the surface of the instrument; Vn is the normal movement speed of the metal; WN is the normal speed of the tool; ST - rubbing voltage;
- yield voltage as a function of the deformable metal parameters, at a given point; - average voltage; - the intensity of the rate of deformation; x0 - the rate of deformation of comprehensive compression; KT is a penalty factor on the slide rate of the metal according to the instrument (specified by the method of iterations) KN - a penalty factory for the penetration of metal into the tool; M is the conditional viscosity of the metal, is specified by the method of hydrodynamic approximations; - tension voltage or backrest during rolling; Fn is the cross-sectional area of \u200b\u200bthe end of the pipe to which the tension or the sub-station is applied.
The calculation of the deformation and speed mode includes the distribution of the deformation states by the diameter, the necessary value of the plastic tension coefficient by the state of the Zob, the calculation of the hood coefficients, roll the diameters of the rolls and the speed of rotation of the main drive engines, taking into account the characteristics of its design.
For the first cells of the mill, including the first crate, which rolls, and for the latter, placed after the last crate, rolls, the plastic tension coefficients in them zr.i less than the required Zob. Through such a distribution of plastic tension coefficients over all cages, the calculated wall thickness at the output of it is greater than necessary on the reduction route. To compensate for the insufficient pulling ability of the tanks located in the first and after the last cells, which ride, it is necessary using an iterative calculation to find such a value of the Zob, so that the calculated and specified wall thickness at the outlet from the state were the same. The greater the magnitude of the required total plastic tension coefficient at the state of Zob, the greater the error in its definition without iterative calculation.
After the iterative calculations calculated the coefficients of the front and rear plastic tension, the thickness of the pipe wall at the inlet and output of the deformation cells along the cities of the reducing mill, we finally determine the position of the first and last cells, which ride.
Of course, the diameter is determined through the central angle qk.p. Between the vertical axis of symmetry of the roll of the roll and the line conducted from the center of the caliber coincides with the axle of rolling into the point on the surface of the caliber stream, where the neutral line of the deformation center is located on its surface, is conditionally located parallel to the rolling axis. The magnitude of the angle of the QK.P., first of all, depends on the value of the rear zado coefficient. and front zer. tension, as well as coefficient
Hood.
Determination of rolling diameter in the magnitude of the angle QK.P. Usually performed for the caliber, has a circle shape with a center in the rolling axis and a diameter equal to the average diameter of the DSR caliber.
The greatest errors in determining the quantity of the diameter without taking into account the actual geometric size of the caliber will be for the case when the rolling conditions determine its position or at the bottom or at the caliber reservation. The greater the real form of caliber will differ from the circle accepted in the calculations, the more so this error will be.
The maximum possible range of changes in the actual diameter value, the caliber roller is a roll of roll stream. The greater the amount of rolls forms a caliber, the more relative error of determining the diameter without taking into account the actual geometric size of the caliber.
With increasing partial compression of the pipe diameter in caliber, it grows the difference of its shape from the circular. So, with an increase in the compression of the pipe diameter of 1 to 10%, the relative error in determining the quantity of the diameter without taking into account the actual geometric sizes of caliber increases from 0.7 to 6.3% for two-color, 7.1% - for trival and 7.4% - For chotirohipwalkovoy "Katya" Tilt when kinematic rolling conditions, rolling diameter located along the bottom of the caliber.
Simultaneous increase in the same
Ilyashenko A.V. - Associate Professor of the Department "Construction Mechanics"
Moscow State Construction University,
Candidate of Technical Sciences
The study of the bearing capacity of compressed elastic thin-walled rods with the initial dawning and undergoing local loss of stability is associated with the definition of the reduced cross section of the rod. The main provisions adopted for the study of a stress-deformed state in the cratery stage of compressed nonideal thin-walled rods are given in the works. This article discusses the core behavior of the rods, which are submitted in the form of a set of jointly working elements - plates with the initial death, imitating the work of the shelves of corner, brass and cross-shaped profiles. These are the so-called plates-plates with one elastically squeezed edge and other free (see Sync). In the works such a plate refers to type II.
It was found that the destructive load characterizing the carrying ability of the rod significantly exceeds the load r (M) load, at which the local loss of stability of the imperfect profile occurs. From the graphs represented by B, it can be seen that the deformations of the longitudinal fibers along the perimeter of the cross section in the crate stage become extremely unequal. In the fibers removed from the roiber, the deformation of compression with an increase in the load decreases, and with loads close to the limit, due to the sharp twist of these fibers due to the initial dilutions and the increasing arrows of longitudinal semi-fellows, which were formed after the local loss of stability, appear and intensively grow deformations. stretching.
The cross-sectional sections with spinning longitudinal fibers are discharged by voltages, as if turn off from the rod operation, weakening the effective cross section and reducing its rigidity. So, carrying ability thin-wing profile Not limited to local stability loss. The full load perceived by more rigid (less curved) cross-sectional areas can significantly exceed the value of r (m).
We obtain an effective, reduced section, eliminating non-working areas of the profile. To do this, use the expression for the function of the voltage F K (x, y), which describes the stress state of the K-oh plate type II (see).
Let us turn to the cylinder stresses σ kh (in the direction of the outer compressive force), determined in the most unfavorable cross section of the rod (x \u003d 0). We write them in general form:
Σ kx \u003d ∂ 2 Ф k (a km, y, f kj, f koj, β c, d, β c, d, j, β, s) / ∂ y 2, (1)
where constant integration A Km (m \u003d 1.2, ..., 6) and the arrows of the components of the acquired deflections F kj (j \u003d 1.2) are determined from the solution of the system of resolution equations. This system of equations includes non-linear variational equations and boundary conditions describing the joint work of nonideal profile records. Arrows f koj (j \u003d 1,2, ..., 5) components of the initial deflection of the K-th record are determined for each type of profile experimentally;
ℓ - the length of the sustainability of the half-wave formed during the local loss;
S - plate width;
β c, d \u003d cs 2 + dℓ 2;
β c, d, j \u003d cs 4 + dℓ 2 s 2 + gℓ 4;
c, D, J - whole positive numbers.
The reduced or effective width of the reduced cross section of the plate-shelf (type II) is denoted by s p. To determine it, we repel the conditions for the transition from the actual cross section of the rod to the reduced:
1. Voltages in longitudinal fibers at the initial face of the plate (at y \u003d 0), adjacent to the edge (see the sinokun), remain the same as those obtained by nonlinear theory (1):
where f 2 kr \u003d f 2 kr + 2f k0r f kr.
To determine the voltage σ k2 \u003d σ k Max, it is necessary to substitute in (1) the ordinate of the most loaded longitudinal fiber, which is from the condition: ∂σ kx / ∂y \u003d 0.
2. The sum of internal efforts in the plate during the transition to a reduced section in the direction of the compressive force does not change:
3. The moment of inner effort relative to the axis passing through the initial face (y \u003d 0) perpendicular to the plane of the plate, remains the same:
It is obvious from the drawing that
σ 'k2 \u003d σ k1 + y n (σ k2 -σ k1) / (y p + s n). (five)
We write a system of equations to determine the reduced plate width S p. To do this, we substitute (1) and (5) in (3) and (4):
where α \u003d πs / ℓ; F kr, ξ \u003d f kr f koξ + f kr f kξ + f kor f kξ;
R, ξ - whole positive numbers.
The resulting system of equations (6) and (7) makes it possible to define the reduced width S p each of the shelves of the components of the compressed undergoing local stability loss thin-walled rod. Thus, the actual cross section of the profile was replaced by the reduced.
The proposed method seems to be useful both in theoretical and practical plan when calculating the carrying capacity of compressed pre-sparkled thin-walled rods in which local wave formation is permissible.
UDC 621.774.3.
Investigation of the dynamics of changes in the thickness of the pipe wall during reduction
K.Yu. Yakovleva, B.V. Barichko, V.N. Kuznetsov
The results of an experimental study of the dynamics of changes in the thickness of the walls of the pipe wall during rolling, drawing in monolithic and roller wipes. It is shown that with an increase in the degree of deformation, a more intense increase of the thickness of the pipe wall is observed in rolling and drawing processes in roller wolves, which makes their use promising.
Keywords: cold-deformed pipes, thick-walled pipes, pipe drawing, pipe wall thickness, the quality of the inner surface of the pipe.
The existing technology for the manufacture of home-deformed thick-walled pipes of a small diameter of corrosion-resistant steels provides for the use of cold rolling processes on CPT mills and subsequent non-free-free drawing in monolithic wolves. It is known that the preparation of small-diameter pipes with cold rolling is associated with a number of difficulties caused by a decrease in the rigidity of the rod-mandrel system. Therefore, to obtain such pipes, the process of drawing is used mainly by irrelevant. The nature of the change in the thickness of the pipe wall in case of displeasure is determined by the ratio of the wall thickness S and the outer diameter D, and the absolute value of the change does not exceed 0.05-0.08 mm. At the same time, the thickening of the wall is observed at the S / D ratio< 0,165-0,20 в зависимости от наружного диаметра заготовки . Для данных соотношений размеров S/D коэффициент вытяжки д при волочении труб из коррозионно-стойкой стали не превышает значения 1,30 , что предопределяет многоцикличность известной технологии и требует привлечения новых способов деформации.
The aim of the work is a comparative experimental study of the dynamics of changes in the thickness of the pipe wall in the reducing processes with rolling, dragging in monolithic and roller wolves.
Cold-focused pipes were used as blanks: sizes 12.0x2.0 mm (S / D \u003d 0.176), 10.0x2.10 mm (S / D \u003d 0.216) from steel 08x14mf; dimensions of 8.0x1.0 mm (S / D \u003d 0.127) from steel 08x18H10T. All pipes were in an annealed state.
The drawing in monolithic wolves was carried out on the chain-free steel mill with force of 30 kN. For roller drawing, a wip-2 / 2.180 roller pairs were used. Relicing in the roller wolf was performed using a system of calibers "oval - circle". The reduction of pipes by rolling was carried out according to the calibration scheme "oval" in a two-color crate with rollers with a diameter of 110 mm.
At each stage of deformation, samples were taken (5 pcs. For each study option) to measure the outer diameter, the thickness of the wall and roughness of the inner surface. The measurement of the geometric sizes and roughness of the surface of the pipes was performed using an electronic TTTC-TT. Electronic point micrometer, SURFTEST SJ-201 profilometer. All tools and devices passed the necessary metrological calibration.
Cold deformation parameters of pipes are shown in the table.
In fig. 1 shows the graphs of the dependence of the value of the relative increase in the wall thickness on the degree of deformation E.
Analysis of graphs in Fig. 1 shows that when rolling and drawing in a roller wolf, compared with the process of drawing in a monolithic wolf, a more intensive change in the thickness of the pipe wall is observed. This, according to the authors, is due to the difference in the diagram of the stress state of the metal: when rolling and roller drawing, tensile stresses in the deformation focus have smaller values. The location of the wall thickness changes in the roller drawing below the curve change in the wall thickness during rolling is caused by several large tensile stresses during roller drawing due to the axial application of the deformation force.
Observed during rolling the extremum function of changing the wall thickness on the degree of deformation or relative compression along the outer diameter corresponds to the value S / D \u003d 0.30. By analogy with hot reducing rolling, where the decrease in the wall thickness is observed at S / D\u003e 0.35, it can be assumed that a decrease in the wall thickness with a ratio of S / D\u003e 0.30 is characterized by rolling.
Since one of the factors determining the nature of the change of wall thickness is the ratio of tensile and radial stresses, which in turn depends on the parameter
Patent number Pipe sizes, mm S, / D, Si / SC Di / DO є
Reduction rolling (pipes made of steel grade 08x14mf)
About 9.98 2,157 o, 216 1, o 1, o 1, o
1 9,52 2.2 ° O, 2Z4 1, OZ4 O, 954 1, OZ 8 O, O4
2 81O 2, Z5O O, 29O 1, O89 O, 812 1,249 o, 2O
C 7, O1 2, Z24 O, SZ2 1, O77 O, 7O2 1,549 o, Z5
Redation rolling (pipes made of steel grade 08x18N10T)
About 8, o6 1, o2o o, 127 1, o 1, o 1, o
1 7, OZ 1,1ZO O, 161 1,1O8 O, 872 1, O77 Oh, O7
2 6,17 1,225 0,199 1,201 o, 766 1,185 o, 16
C 5,21 1, Z1O O, 251 1,284 O, 646 1.4O6 O, 29
Reduction with dragging in the roller wolf (pipes made of steel grade 08x14mf)
About 12, oo 2,11 o, 176 1, o 1, o 1, o
1O, 98 2.2 o, 2OO 1, O4Z O, 915 1, O8O Oh, O7
2 1O, O8 2.27 o, 225 1, O76 O, 84O 1,178 o, 15
C 9, O1 2, ZOO O, 2O1 1, O9O O, 751 1, Z52 O, 26
Reduction with dragging in the monolithic wolf (pipes made of steel grade 08x14mf)
About 12, oo 2,11 o, 176 1, o 1, o 1, o
1O, 97 2,1Z5 0.195 1, O12 O, 914 1,1O6 O, 1O
2 9.98 2,157 o, 216 1, o22 o, 8z2 1,118 o, 19
C 8,97 2,16O O, 241 1, O24 o, 748 1,147 o, zo
Di, si - respectively, the outer diameter and the thickness of the pipe wall in mr. Passage.
Fig. 1. The dependence of the value of the relative increase in the thickness of the pipe walls on the degree of deformation
the RA S / D, it is important to study the effect of the relation S / D to the position of the extremum function of the change in the thickness of the pipe wall thickness in the reduction process. According to the work given, with smaller ratios of S / D, the maximum value of the thickness of the pipe wall is observed at large deformations. This fact was examined on the example of the process of reduction of pipe rolling with dimensions of 8.0x1.0 mm (S / D \u003d 0.127) of steel 08x18H10T in comparison with the pipe rolling data with dimensions of 10.0x2.10 mm (S / D \u003d 0.216) steel 08x14mf. The measurement results are shown in Fig. 2.
Critical degree of deformation, in which the maximum value of the wall thickness was observed when rolling pipes with the ratio
S / D \u003d 0.216, amounted to 0.23. When rolling pipes from steel 08x18H10T, the extremum of the wall thickness of the wall is not achieved, since the ratio of the size of the pipe S / D even at the maximum degree of deformation did not exceed 0.3. An important circumstance is that the dynamics of increasing the thickness of the wall during the reduction of pipes with rolling is in reverse dependence on the ratio of the s / d sizes of the source pipe, which demonstrate the graphs shown in Fig. 2, a.
Analysis of curves in Fig. 2, B shows also that the change in the ratio of S / D in the process of rolling pipes from steel grade 08x18H10T and pipes made of steel grade 08x14MF has a similar qualitative character.
S0 / a) \u003d O, 127 (08x18n10t)
S0 / 00 \u003d 0.216 (08x14mf)
Degree of deformation, b
Va \u003d 0; 216 (08x14mf)
(SO / DA \u003d 0A21 08x18H10T) _
Degree of deformation, є
Fig. 2. Change the thickness of the wall (A) and the ratio S / D (b) depending on the degree of deformation when rolling pipes with various source ratio S / D
Fig. 3. The dependence of the relative value of the roughness of the inner surface of the pipes on the degree of deformation
In the process of reduction different ways The roughness of the inner surface of the pipes in the magnitude of the average radiation of the radiation of the radiation of the RA was also evaluated. In fig. 3 shows the graphs of the dependences of the relative value of the parameter Ra on the degree of deformation during the reduction of pipes with rolling and drawing in monolithic wagons ^ ag, Ra0 - respectively, the parameters of the rough
the inner surface of the pipes in the Mr passage and on the source pipe).
Analysis of curves in Fig. 3 shows that in both cases (rolling, drawing), an increase in the degree of deformation during the reduction leads to an increase in the RA parameter, that is, it worsens the quality of the inner surface of the pipes. The dynamics of changes (increase) of the roughness parameter with increasing the degree of deformation in the case of
duzing pipes with rolling in two-color calibers significantly (by about twice) exceeds the same indicator in the process of drawing in monolithic wolves.
It should also be noted that the dynamics of changes in the inner surface roughness parameter consistent with the above description of the dynamics of the wall thickness change for the considered methods of reduction.
According to the results of research, the following conclusions can be drawn:
1. Dynamics of changes in the thickness of the pipe walls for the considered methods of cold reduction of the same type - intense thickening with an increase in the degree of deformation, the subsequent slowdown in the wall thickness increase with a certain maximum value with a certain ratio of the s / d pipe size and the subsequent reduction in the wall thickness increase.
2. The dynamics of changes in the thickness of the pipe wall is in the inverse dependence on the ratio of the sizes of the source pipe S / D.
3. The greatest dynamics of the increase in the wall thickness is observed in rolling and drawing processes in roller wolves.
4. An increase in the degree of deformation during the reduction of rolling and drawing in monolithic wolves leads to a deterioration of the state of the inner surface of the pipes, and the increase in the RA roughness parameter during rolling occurs more intensively than with drawing. Considering the conclusions and the nature of the change in the wall thickness in the deformation process, it can be argued that to drag pipes in roller mills
the parameter Ra will be less intense than for rolling, and more intense in comparison with monolithic dragging.
The information on the patterns of the cold reduction process will be useful in designing the manufacturer of home-focused pipes from corrosion-resistant steels. In this case, promising for a set of pipe wall thickness and reducing the number of passages is the use of the drawing process in roller wolves.
Literature
1. Bisk, M.B. Cold deformation steel pipes. 2 h. 1: Preparation for deformation and drawing / M.B. Bisk, I.A. Sin, VB Slavin. -Sverdlovsk: Mid-Ural. kn. Publishing house, 1976. - 232 p.
2. Savin, G.A. Fingering of pipes / G.A. Savin. -M: Metallurgy, 1993. - 336 p.
3. Schweikin, V.V. Cold rolling technology and pipe reduction: studies. Allowance / V.V. Schwekin. - Sverdlovsk: Publishing House. CM. Kirov, 1983. - 100 s.
4. Technology and equipment of tubular production / E. Saddy, A. S. Vavilin, V.G. Zimovets and others; Ed. V.Ya. Sidic. - M.: Intermet of Engineering, 2007. - 560 p.
5. Barichko, B.V. Basics of technological processes OMD: Abstract of lectures / B.V. Barichko, F.S. Dubinsky, V.I. Crank. - Chelyabinsk: Publishing House, Juragu, 2008. - 131 p.
6. Potapov, I.N. Pipe production theory: studies. For universities / I.N. Potapov, A.P. Koli, V.M. Druyan. - M.: Metallurgy, 1991. - 424 p.
Yakovleva Ksenia Yuryevna, Junior Researcher, JSC Russian Research Institute of Pipe Industry (Chelyabinsk); [Email Protected]
Barich Boris Vladimirovich, Deputy Head of the Seamless Pipe Department, OJSC Russian Research Institute of Pipe Industry OJSC (Chelyabinsk); [Email Protected]
Kuznetsov Vladimir Nikolaevich, head of the cold deformation laboratory of the Central Factory Laboratory, JSC "Sinar Pipe Plant" (Kamensk-Uralsky); [Email Protected]
Bulletin of the South Ural State University
Series "MetallureGy" ___________2014, vol. 14, no. 1, pp. 101-105
Study of Dynamic Changes of The Redu Wall Thickness In The Reduction Process
K.Yu. Yakovleva, The Russian Research Institute of the Tube and Pipe Industries (Rosniti), Chelyabinsk, Russian Federation, [Email Protected],
B.V. Barichko, The Russian Research Institute of the Tube and Pipe Industries (Rosniti), Chelyabinsk, Russian Federation, [Email Protected],
V.N. Kuznetsov, JSC "SINARSKY PIPE PLANT", KAMENSK-URALSKY, RUSSIAN FEDERATION, [Email Protected]
The Results of The Experimental Study of Dynamic Changes for The Pipe Wall Thickness During Rolling, Drawing Both in Single-Piece and Roller Dies Are Described. The Dexts show That with the Deformation Increasing The Faster Growth of The Pipe Wall Thiknness is Observed in Rolling and Drawing with the Roller Dies. The Conclusion CAN BE Drawn That The Most Promising One The Conclusion CAN BE Drawn Dies Is The Most Promising One
Keywords: Cold-Formed Pipes, Thick-Wall Pipes, Pipe Drawing, Pipe Wall Thickness, Quality of the Inner Surface of Pipe.
1. Bisk M.B., Grekhov I.A., Slavin V.B. Kholodnaya deformatsiya stal "Nykh Trub. Podgotovka K Deformatsii I Volochenie. Sverdlovsk, Middle Ural Book Publ., 1976, Vol. 1. 232 p.
2. Savin G.A. VOLOCHENIE TRUB. MOSCOW, METALLURGIYA PUBL., 1993. 336 p.
3. Shveykin v.V. Tekhnologiya Kholodnoy Prokatki I Redutsirovaniya Trub. Sverdlovsk, Ural Polytechn. Inst. Publ., 1983. 100 p.
4. Osadchiy v.ya., Vavilin A.S., Zimovets V.G. et al. Tekhnologiya I OBRUDOVANIE TRUBNOGO PROIZVODSTVA. Osadchiy v.ya. (Ed.). MOSCOW, INTERMET ENGINEERING PUBL., 2007. 560 p.
5. Barichko B.V., Dubinskiy F.S., Kraynov V.I. Osnovy Tekhnologicheskikh Protsessov Omd. Chelyabinsk, South Ural St. Univ. Publ., 2008. 131 p.
6. Potapov I.N., Kolikov A.P., Druyan V.M. Teoriya Trubnogo Prizvodstva. Moscow, Metallurgiya Publ., 1991. 424 p.
Thesis on the topic:
Production of pipes
1. Sort and requirements of regulatory documentation for pipes
1.1 Pipe Sort
OJSC "Crossow Sukavod" is one of the largest manufacturers of tubular products in our country. Its products are successfully sold both within the country and abroad. Products manufactured at the factory meets the requirements of domestic and foreign standards. International quality certificates issued by organizations such as: American Oil Institute (API), German TUV Certification Center - Ralend.
The T-3 workshop is one of the main workshops of the enterprise, produced by them complies with the standards shown in Table. 1.1.
Table 1.1 - Standards of pipes manufactured
In the workshop, pipes made of carbon, alloyed and highly doped steel grades with a diameter d \u003d 28-89mm and the wall thickness s \u003d 2.5-13mm are produced.
The main workshop specializes in the production of pump-compressor pipes, general-purpose pipes and pipes intended for the subsequent cold redisture.
The mechanical properties of the produced pipes must correspond to the specified in Table. 1.2.
1.2 Requirement of regulatory documentation
Production of pipes in the T-3 workshop The Crug is carried out on various regulatory documents such as GOST, API, DIN, NFA, ASTM and others. Consider the requirements of the presented DIN 1629.
1.2.1Statim
This standard applies to seamless round tubes from unallown steels. Chemical composition Steels used for pipe production is given in Table 1.3.
Table 1.2 - Mechanical properties of pipes
Table 1.3 - Chemical composition of steels
Pipes manufactured according to this standard are used primarily in various devices in the manufacture of tanks and laying pipelines, as well as in general engineering and instrument making.
The dimensions and limit deviations of the pipes are shown in Table 1.4., Table 1.5., Table.1.6.
The length of the pipe is determined by the distance between its ends. Types of pipe length are shown in Table 1.4.
Table 1.4 - Types of length and permissible length deviations
Table 1.5 - permissible deviations of diameter
Table 1.6 - Allowable wall thickness deviations
Pipes should be as round as possible. The deviation from the roundness should lie within the permissible deviations for the outer diameter.
Pipes must be straight on the eye, if necessary, special requirements for straight can be installed.
Pipes must be cropped perpendicular to the pipe axis and should not have burrs.
Values \u200b\u200bfor linear masses (weight) are given in DIN 2448 standard. The following deviations from these values \u200b\u200bare allowed:
for a separate pipe + 12% - 8%,
for supply weighing at least 10T + 10% -5%.
In standard designation for pipes of the corresponding DIN 1629, it is indicated:
Naming (tube);
The main number of DIN dimensional standard (DIN 2448);
The main sizes of the pipe (outer diameter × wall thickness);
Main number technical Conditions Supplies (DIN 1629);
Abbreviated name of steel brand.
An example of the conditional designation of the pipe according to DIN 1629 with an outer diameter of 33.7 mm and a wall thickness of 3.2 mm from steel ST 37.0:
Pipe DIN 2448-33.7 × 3.2
DIN 1629-ST 37.0.
1.2.2 Technical requirements
Pipes should be made in accordance with the requirements of the standard and technological regulations approved in the prescribed manner.
On the outer and inner surface of the pipes and the coupling should not be captured, shells, sunsets, bundles, cracks and sandy.
Debate and stripping of these defects are allowed, provided that their depth does not exceed the limit minus deviation over the wall thickness. Welding, Zackecanka or sealing of defective places is not allowed.
In places where the wall thickness can be measured directly, the depth of defective places may exceed the specified value under the condition that the minimum wall thickness is preserved, which is determined as the difference between the nominal thickness of the pipe wall and the maximum deflection limit for it.
Separate minor fears, dents, risks, a thin layer of scale and other defects caused by the production method, if they do not derive the wall thickness beyond the limits of minus deviations.
Mechanical properties (yield strength, tensile strength, the relative extension during the break) must comply with the values \u200b\u200bgiven in Table 1.7.
Table 1.7 - Mechanical properties
1.2.3 Acceptance rules
Pipes are presented to accepting parties.
The party should consist of pipes of one conditional diameter, one wall thickness and strength group, of one type and one execution and accompanied by a single document certifying the compliance of their quality to the requirements of the standard and containing:
Name of the manufacturer;
Conditional pipe diameter and wall thickness in millimeters, pipe length in meters;
Pipe type;
Group of strength, smelting number, mass fraction of sulfur and phosphorus for all carriages included in the batch;
Pipe numbers (from - up to each melting);
Test results;
Standard designation.
Check external viewThe values \u200b\u200bof defects and geometric sizes and parameters should be subjected to each part of the party.
The mass fraction of sulfur and phosphorus should be checked from each melting. For pipes made of metal of another enterprise, the mass fraction of sulfur and phosphorus should make a document on the quality of the manufacturer of the metal manufacturer.
To check the mechanical properties of the metal are selected by one pipe of each size from each melting.
To check for flattening, select one pipe from each melting.
Testing for tightness internal hydraulic pressure should be subjected to each pipe.
Upon receipt of unsatisfactory test results, at least one of the indicators on it is carried out by repeated tests on a double sample from the same batch. Results of repeated tests apply to the entire batch.
1.2.4 Test methods
Inspection of the outer and inner surface of the pipes and the couplings are visually produced.
The depth of the defects should be checked in an idle or in another way in one-three places.
Checking the geometrical sizes and parameters of pipes and couplings should be carried out using universal measuring instruments or special devices that ensure the necessary measurement accuracy, in accordance with the technical documentation approved in the prescribed manner.
The curved in the end portions of the pipe is determined, based on the magnitude of the deflection boom, and is calculated as the prolvious from the division of the deflection boom in millimeters to the distance from the place - measurements to the nearest end of the pipe in meters.
Checking pipes by weight should be made on special means For weighing with accuracy providing the requirements of this Standard.
Tensile test should be carried out according to DIN 50 140 on short longitudinal samples.
To check the mechanical properties of the metal from each selected tube, one sample is cut out. Samples should be cut along any end of the pipe by a method that does not cause changes in the structure and mechanical properties of the metal. It is allowed to straighten the ends of the sample to capture the triggers of the test machine.
The duration of the test hydraulic pressure must be at least 10 seconds. When tested in the pipe wall, leaks should not be detected.
1.2.5 Marking, Packaging, Transportation and Storage
Marking of pipes should be carried out in the following volume:
On each pipe at a distance of 0.4-0.6 m from its end, the marking should be clearly applied with an impact or kating:
Pipe number;
Trademark of the manufacturer;
Month and year of release.
The place of application of marking should be circled or emphasized by stable light paint.
The height of the marking signs should be 5-8 mm.
With a mechanical method of applying pipe marking, it is allowed to locate it in one row. It is allowed on each pipe to marke the melting number.
Next to the labeling shock mode or comprehension on each pipe should be labeled stable light paint:
Conditional diameter of the pipe in millimeters;
Wall thickness in millimeters;
Type of execution;
Name or trademark of the manufacturer.
The height of the marking signs should be 20-50 mm.
All marking signs should be applied along the pipe forming. It is allowed to apply marking signs perpendicular to the rolling method.
When loading in one car should be pipes of only one batch. Pipes are transported in packages, firmly linked not less than two places. The mass of the package should not exceed 5 tons, and at the request of the consumer - 3 tons. It is allowed to ship in one car packages of pipes of different batches, provided that they are separated.
2. Technology and equipment for pipe production
2.1 Description of the main equipment of the T-3
2.1.1 Description and short technical characteristics of a stove with a steps (PSH)
The furnace with a walking subway shop T-3 is designed for heating round blanks With a diameter of 90 ... 120 mm, a length of ... 10 m from carbon, low-alloyed and stainless steel stamps before firmware on TPA-80.
The furnace is located in the room of the T-3 shop on the second floor in flights A and B.
The furnace project was performed by the gyrometric of the city of Sverdlovsk in 1984. Commissioning was carried out in 1986.
The furnace is a rigid metal structure touched by refractory and thermal insulation materials. Inner dimensions Furnaces: Length - 28.87 m, width - 10.556 m, height - 924 and 1330 mm, the operational characteristics of the furnace are presented in Table 2.1. Under the furnace is made in the form of fixed and movable beams, with which the blanks are transported through the furnace. The beams are tuppurated with thermal insulating and refractory materials and framed by a special headset from heat-resistant casting. The upper part of the beam is made of Mc-90 mullitoxorund. The furnace arch is made suspended from the shaped refractory materials and is isolated insulating material. For maintenance furnace and maintenance technological process Walls are equipped with work windows, boot window and metal unloading window. All windows are equipped with dampers. The heating of the furnace is carried out by natural gas, grounded with the burner type gr (Radiation burner low pressure) installed on the arch. The furnace is divided into 5 thermal zones of 12 burners in each. The combustion air is supplied by two VM-18A-4 fans, one of which serves as a backup. The flue gases are removed through the smoke collector, located on the arch at the beginning of the furnace. Further, according to the system of metal lined smoking products and horses, with the help of two Dymososos, WGDN-19 flue gases are thrown into the atmosphere. The flipper was installed with a loop two-way tubular 6-sequeous loop recovery (CP-250) for heating the air supplied to burning. For more complete disposal of exhaust gas heat, the smoke removal system is equipped with a single-chamber furnace for heating mandrels (PPO).
The issuance of the heated billet from the furnace is carried out with the help of internal water-cooled rolling rollers whose rollers have a heat-resistant nozzle.
The furnace is equipped with a system of industrial television. Between the control panels and the shield of kipia there is a loudspeakers.
The furnace is equipped with automatic thermal regime control systems, automatic security, control nodes of operation parameters and signaling deviations from the norm. The following parameters are subject to automatic regulation:
Furnace temperature in each zone;
The ratio of "gas-air" on zones;
Gas pressure in front of the furnace;
Pressure in the workspace of the furnace.
In addition to automatic modes, remote mode is provided. Automatic control system includes:
Furnace temperature in zones;
The temperature in the width of the furnace in each zone;
Temperature of gases flowing from the furnace;
Air temperature after heat recovery;
The temperature of the outgoing gases in front of the recuperator;
Smoke temperature in front of the smoke;
Natural gas consumption on the furnace;
Air flow to the furnace;
Discharge in Borov in front of the smoke;
Gas pressure in the general manifold;
Pressure gas and air in zone collectors;
Pressure in the furnace.
The furnace contains a cut-off of natural gas with a light-sound signaling when the gas and air pressure drops in the zone collectors.
| Natural gas consumption on the oven (maximum) Nm 3 / hour | 5200 |
| 1 zone | 1560 |
| 2 zone | 1560 |
| 3 zone | 1040 |
| 4 zone | 520 |
| 5 zone | 520 |
| Natural gas pressure (maximum), kpa before | |
| oven | 10 |
| burner | 4 |
| Air flow to the furnace (maximum) nm 3 / hour | 52000 |
| Air pressure (maximum), kpa before | |
| oven | 13,5 |
| burner | 8 |
| Pressure under the archway | 20 |
| Metal Heating Temperature, ° C (Maximum) | 1200...1270 |
| Chemical composition of combustion products in the 4th zone,% | |
| CO 2 | 10,2 |
| O 2. | 3,0 |
| SO | 0 |
| Temperature of combustion products in front of the recuperator, ° C | 560 |
| Air heating temperature in the recuperator, ° С | Up to 400. |
| Pace of dispensing of blanks | 23,7...48 |
| Furnace performance, TN / hour | 10,6... 80 |
Emergency sound alarm system also works as:
Raising the temperature in the 4th and 5th zones (t cp \u003d 1400 ° C);
Increasing the temperature of the flue gases in front of the recuperator (t with p \u003d 850 ° C);
Increasing the temperature of the flue gases in front of the smoke system (t cp \u003d 400 ° C);
Falling the pressure of cooling water (p cf \u003d 0.5 atm).
2.1.2 Brief Technical Characteristics Hot Cutting Line
The hot cutting line of the workpiece is designed for the problem of the heated rod in the scissors, cutting the workpiece on the required lengths, the removal of cutting blanks from scissors.
A brief technical characteristic of the hot cutting line is presented in Table 2.2.
The composition of the hot cutting line equipment includes scissors themselves (SCMZ designs) for cutting blanks, mobile stop, transport roller, protective screen for protecting equipment from thermal radiation from the PSP unloading window. Scissors are designed for wasteless cutting of the metal, however, as a result of any emergency causes, a residual crawling is formed, then a chute and a box in the pit is installed, near scissors. In any case, the operation of the hot cutting line of the workpiece must be organized so as to eliminate the formation of cropping.
| Parameters of the cutting rod | |
| Length, M. | 4,0…10,0 |
| Diameter, mm. | 90,0…120,0 |
| Maximum mass, kg | 880 |
| Length of blanks, m | 1,3...3.0 |
| Temperature rods, about with | 1200 |
| Performance, pcs / h | 300 |
| Transportation speed, m / s | 1 |
| Movement stop, mm | 2000 |
| Roller | |
| Barrel diameter, mm | 250 |
| Length of barrels, mm | 210 |
| Riding diameter, mm | 195 |
| Step rollers, mm | 500 |
| Water consumption on the roller water-cooled, m 3 / h | 1,6 |
| Water consumption for a roller water cooled with water-cooled letters, m 3 / h | 3,2 |
| Water consumption on the screen, m 3 / h | 1,6 |
| Sound level, dB, no more | 85 |
After heating the rod and issuing it, it passes through the thermostat (to reduce the temperature drop in the length of the workpiece), reaches the mobile stop and is cut on the workpiece of the required length. After the production of cut, mobile focus rises with a pneumatic cylinder, the blank is transported by roller. After her pass over the emphasis, it falls into the working position and the reuse cycle is repeated. To remove the scale from the roller rollers, the hot cutting scissors is provided by the hydrochlorine system, to remove the edge of the chute and the receiving box. The billet after leaving the rolling line of the hot cutting, falls on the adopted rolling rolling roller.
2.1.3 Device and technical characteristics of the main and auxiliary equipment Plot of a firmware
The firmware is designed for firmware of a continuous billet into a hollow sleeve. On TPA-80 there is a 2-rolled firmware mill with barreloidal or invigorate rolls and guide rules. Technical specifications The firmware is presented in Table 2.3.
Before the firmware mill, there is a water-cooled rolling roller, intended for receiving the workpiece from the hot cutting line and transporting it to the center. Rolling consists of 14 water-cooled rollers with an individual drive.
| The dimensions of the stitched workpiece: | |
| Diameter, mm. | 100…120 |
| Length, mm. | 1200…3350 |
| Size Gils: | |
| Outer diameter, mm | 98…126 |
| Wall thickness, mm | 14…22 |
| Length, mm. | 1800…6400 |
| The number of revolutions of the main drive, rpm | 285…400 |
| Gear gear gear | 3 |
| Engine power, kW | 3200 |
| Feed angle, ° | 0…14 |
| Rolling force: | |
| Maximum radial, kN | 784 |
| Maximum axial, kN | 245 |
| Maximum torque on the roll, kNm | 102,9 |
| Diameter of workers rolls, mm | 800…900 |
| Purpose screw: | |
| The greatest move, mm | 120 |
| Travel speed, mm / s | 2 |
The centralrower is designed to knock the center deepening with a diameter of 20 ... 30 mm and a depth of 15 ... 20 mm on the end of the heated billet and is a pneumatic cylinder in which the drummer with a tip slides.
After the centration, the heated blank enters the lattice for subsequent transmission of it in the front desk of the firmware.
The front table of the firmware is designed for receiving the heated billet, rolling through the grid, combining the axis of the workpiece with the axis of the firmware and hold it during the firmware.
On the output side of the mill, roller cores of the mandrel rod, which support and center the rod, both in front of the firmware and in the firmware process, when high axial efforts are operating and its longitudinal bending is possible.
In the centers there is a stationary hard-adjusting mechanism with the opening head, it serves to perceive the axial efforts acting on the rod with the mandrel, adjusting the position of the mandrel in the focus of deformation and skipping the sleeve beyond the firmware.
2.1.4 Device and technical characteristics of the main and auxiliary equipment of a continuous steel section
The continuous camp is designed to rolling the rough pipes with a diameter of 92mm with a wall thickness of 3 ... 8 mm. Rolling is carried out on a long floating mandrel with a length of 19.5 m. The brief technical characteristics of the continuous mill is shown in Table 2.4., Table 2.5. The gear ratios of gearboxes are given.
When rolling, the continuous mill operates as follows: Rolling behind the firmware steel sleeve is transported at a speed of 3 m / s to the mobile stream and, after stopping, using a chain conveyor is transmitted to the grid before continuous mill and rolls back to the dispenser levers.
| Name | Value | |
| The outer diameter of the draft tube, mm | 91,0…94,0 | |
| Wall thickness of the draft tube, mm | 3,5…8,0 | |
| Maximum length of the draft tube, m | 30,0 | |
| The diameter of the mandrel of the continuous mill, mm | 74…83 | |
| Length mandrel, m | 19,5 | |
| Diameter of wolves, mm | 400 | |
| Length barrel roll, mm | 230 | |
| Neck diameter rolls, mm | 220 | |
| Distance between the axes of the cage, mm | 850 | |
| The course of the upper pressure screw with new rolls, mm | Up | 8 |
| Down | 15 | |
| The course of the lower pressure screw with new rolls, mm | Up | 20 |
| Down | 10 | |
| Upper roll lifting speed, mm / s | 0,24 | |
| The frequency of rotation of engines of the main drive, rpm | 220…550 | |
If there are defects on the sleeve, the operator manual turning on the overlap and the replicaters directs it into the pocket.
The suitable sleeve with a slost lever levers rolls into the chute, pressed the clamps with the clamps, after which the mandrel is introduced into the sleeve using the specifying rollers. Upon reaching the front end of the mandrel of the front cutting of the liner, the clamp is released, and the sleeve is set to the continuous camp with pushing rollers. At the same time, the speed of rotation of pulling rollers mandrels and the sleeve is set in such a way that by the time the sleeve seizure the first cage of the continuous mill the front end of the mandrel was pulled by 2.5 ... 3 m.
After rolling on a continuous mill, the blackspread pipe with the mandrel enters the excavator of the mandrels, a brief technical characteristic is presented in Table 2.6. After that, the pipe rolling is transported to the area of \u200b\u200btrimming of the rear end and is suitable for the stationary pulp on the section of the trimming of the rear end of the pipe, the technical characteristics of the equipment of the plot of PLAK is given in Table 2.7. Having reached the pipe is discharged by a screw dropper on the grille in front of the leveling rolling rolling. Further, the pipe rolls along the grille on the leveling rolling rolling, it is suitable for the slope that determines the length of the trimming, and the piece of the lattice is transmitted from the leveling roller on the lattice before the rear rolling rolling rolling rolling.
The cropped end of the pipe is transmitted by the conveyor for cleaning cropping into a container for a metal scrap, located outside the workshop.
Table 2.5 - gear ratio of continuous mill gearboxes and engine power
2.1.5 Principle of operation of the main and auxiliary equipment of the section of the reduction mill and refrigerator
Equipment for this section is intended for transporting the draft pipe through the installation induction heating, rolling on a reduction mill, cooling and further transportation to the area of \u200b\u200bcold cutting.
Heated draft tubes in front of a reduction mill is carried out in the heating setting of the Inz 9000 / 2.4 consisting of 6-heating blocks (12 inductors) placed immediately before the reduction mill. Pipes enter the induction installation one after another continuous flow. In the absence of pipes from a continuous mill (when the rental stop) is allowed to submit to the induction installation of pending "cold" pipes. The length of the pipes specified in the installation should not be more than 17.5 m.
Type of reduction mill - 24-cable, 3 rolls with two roller reference position and individual drive cell.
After rolling on a reduction mill, the pipe enters either in the sprayer and on the cooling table, or immediately to the mill cooling table, depending on the requirements for the mechanical properties of the finished pipe.
The design and technical characteristics of the sprayer, as well as the parameters of the cooling of pipes in it are the commercial secret "OJSC Crestovor Supply" and in this paper are not given.
Table.2.8. The technical characteristic of the heating unit is presented, in Table 2.9.- A brief technical characteristic of the reducing mill.
Table 2.8 - Brief technical characteristic of the heating installation Inz-9000 / 2.4
2.1.6 Equipment for cutting pipes for measuring lengths
For cutting pipes on the measuring lengths in the T-3 shop, the saw cutting saw of the Wagner model was used by the WVC 1600R model, the technical characteristics of which is given in Table. 2.10. KV6R models are also used - technical characteristics in Table 2.11.
| Name of parameter | Value | |
| Diameter of cut pipes, mm | 30…89 | |
| Width of cut packets, mm | 200…913 | |
| Wall thickness of cut pipes, mm | 2,5…9,0 | |
| Length of pipes after cutting, m | 8,0…11,0 | |
| Length of sliced \u200b\u200bpipe ends | Front, mm. | 250…2500 |
| Rear, mm. | ||
| Diameter of saw disk, mm | 1600 | |
| Number of teeth on saw saw, pcs | Segments | 456 |
| Carwide | 220 | |
| Cutting speed, mm / min | 10…150 | |
| Minimum disk diameter saw, mm | 1560 | |
| Feed the caliper of the disk saw, mm | 5…1000 | |
| Maximum tensile strength, N / mm 2 | 800 | |
2.1.7 Equipment for Pipe Edit
Pipes chopped on measuring lengths in accordance with the order are sent to edit. Edit is carried out on the proper RVV320x8 machines, intended for editing pipes and carbon and low-alloy steel rods and low-alloyed stamps in cold condition with a source curvature up to 10 mm per monthly meter. The technical characteristics of the correct RVV 320x8 machine is given in Table. 3.12.
| Name of parameter | Value |
| Width of the single-row package, mm | Not more than 855. |
| Width of the opening of the clamp of the workpiece, mm | From 20 to 90 |
| Passage in the vertical direction of the clips of the workpiece, mm | No more than 275. |
| Single disk caliper move, mm | 650 |
| Speed \u200b\u200bfeed disk (stepless) mm / min | No more than 800. |
| Quick-reverse saw disk, mm / min | Not more than 6500. |
| Cutting speed, m / min | 40; 15; 20; 30; 11,5; 23 |
| Climbing Package Package Length on Side Side, mm | At least 250. |
| Clamping Package Package Length on the Related Side, mm | Not less than 200. |
| Diameter of saw disk, mm | 1320 |
| Number of segments on a saw disk, pcs | 36 |
| Number of teeth on segment, pcs | 10 |
| Diameter of processed pipes, mm | From 20 to 90 |
| Name of parameter | Value | |
| The diameter of straighted pipes, mm | 25...120 | |
| Thickness of the wall of refined pipes, mm | 1,0...8,0 | |
| Length of strain pipes, m | 3,0...10,0 | |
| Metal flow rate of refined pipes, kgf / mm 2 | Diameter 25 ... 90 mm | Up to 50 |
| Diameter 90 ... 120 mm | Up to 33. | |
| Pipe editing speed, m / s | 0,6...1,0 | |
| Step between axes of rolls, mm | 320 | |
| Diameter of rolls in the neck, mm | 260 | |
| Number of rolls, pcs | Drive | 4 |
| Idle | 5 | |
| Corners setting rolls, ° | 45 ° ... 52 ° 21 ' | |
| The greatest course of the upper rolls from the top edge of the lower, mm | 160 | |
| Drive rotation roll | engine's type | D-812. |
| Voltage, B. | 440 | |
| power, kWt | 70 | |
| Rotation speed, rpm | 520 | |
2.2 Existing pipe production technology on TPA-80 OJSC "Cruscharovavod"
Entering the workpiece in the form of a rod, stored in the domestic warehouse. Before running in production, it is subjected to a special rack by selective inspection, if necessary - repair. In the preparation site, scales are installed to control the weight, launched metal in production. Billets from a warehouse with an electromostic crane are fed to the loading grille in front of the furnace and loaded into the heating furnace by the steering pump in accordance with the schedule and the rate of rental.
Compliance with the laying scheme of blanks is made visually by the metal board. The billet in the oven is loaded individually in each, through one or more steps of the guide slabs of movable beams depending on the rental rate and multiplicity of cut. When changing the steel grade, melting and sizes of pipes, the landing unit produces the separation of steel grades, melting as follows: with the length of the workpiece 5600-8000 mm, the smelting is separated by offset of the first first rods in the width of the furnace; The steel grades are separated by offset of the four first rods in the width of the furnace; With the length of the workpiece 9000-9800mm, the separation of steel grades, melting from each other from each other with a spacker with an interval of 8-10 steps, as well as the counting of the amount planted in the PSP and the billet issued, which are controlled by the PSP metal heightener and the scissors with hot cutting sprinkle by reconciliation with control panels . TPA-80; When changing the size (rolling mill) of rolling pipes, Poster metal to the furnace stops behind "5-6 steps" to stop the mill, when the metal stopped on the transshipment, "squeezes 5-6 steps" back. Moving billets through the furnace is carried out by three moving beams. In pauses, moving cycle, movable beams are installed at the feed level. The required heating time is ensured by measuring the step cycle time. The overpressure in the working space should be from 9.8 Pa to 29.4 pa, the air flow rate \u003d 1.1 - 1.2.
When heated in the ovens of the blanks of various stamps, the duration of heating is caused by the metal, the time of staying in the oven which is the largest. High-quality metal heating is ensured by uniform passing of blanks along the entire length of the furnace. Heated billets are issued on the inner risk of unloading, and they are issued to the hot cutting line.
To reduce the underwear of blanks during downtime, a thermostat is provided on a rolling transportation of heated blanks to scissors, as well as the possibility of returning (on the inclusion of reverse) not cut blanks into the oven and finding it during downtime.
During operation, a hot furnace stop is possible. The hot furnace stop is the stopping without turning off the supply of natural gas. With hot stops, movable stove beams are installed at the level of fixed. Loading and unloading windows are closed. Air flow coefficient with a "fuel-air" sequence decreases from 1.1-1.2 to 1.0: -1.1. Pressure in the furnace at the level level becomes positive. When stopping the mill: up to 15 minutes - the temperature of the zones is installed on the lower limit, and "squeeze" metal for two steps; From 15 minutes to 30 minutes - the temperature in zones III, IV, V is reduced by 20-40 0 s, in zones I, II by 30-60 0 s from the lower limit; Over 30 minutes - the temperature in all zones is reduced by 50-150 0 C compared to the lower limit depending on the duration of idleness. The blanks are "stupid" back to 10 steps. With duration of downtime from 2 to 5 hours, it is necessary to free from the billets of the IV and V zone of the furnace. Billets from zones I and II are discharged into pocket. Metal unloading is carried out by a metal flooring with PU-1. The temperature in V and IV zones are reduced to 1000-I050 0 C. At stops for more than 5 hours the entire oven is freed from the metal. The temperature rise is carried out step by 20-30 ° C, with a temperature raising rate of 1.5-2.5 ° C. / min. With an increase in the heating time of the metal due to the low rate of rental, the temperature in I, II, III zones are lowered by b0 0 C, 40 0 \u200b\u200bC, 20 0, respectively, from the lower limit, and the temperature in zones IV, V on the lower managers. In general, during the stable operation of the entire unit, the temperature in zones is distributed as follows (Table 2.13).
After heating, the blank falls on the hot cutting line of the workpiece. The composition of the hot cutting line equipment includes the scissors for cutting the workpiece, mobile stop, transport roller, protective screen for protecting equipment from heat out from the window for unloading the oven with a stepting subsidence. After heating the rod and issuing it, it passes through the thermostat, reach out to the mobile stop and is cut on the workpiece of the required length. After the production of the cut, the mobile focus rises with a pneumatic cylinder, the blank is transported by rolling. After its passage for the stop, it is descended into the working position and the recent cycle continues.
Table 2.13 - Distribution of temperature in the furnaces by zones
A measured billet with rolling for scissors is transmitted to the center. A breeding blank is transmitted to the grid before the firmware mill, which rolls up to a delay and, when the output side is ready, is transmitted to the chute, which is closed with a lid. With the help of the poverty, when the harvest is raised, the blank is set in the deformation zone. In the deformation zone, the billet is firmware on the mandrel held by the rod. The rod rests on the glass of the thrust head of the stubborn-adjustment mechanism, the opening of which does not allow the lock. A longitudinal bending of the rod from axial efforts occurring during rolling is prevented by closed centers whose axes are parallel to the axis of the rod.
In the working position, the rollers are driven around the rod pneumatic cylinder through the lever system. As the front end approaches the sleeve, the core rollers are consistently bred. After the end of the billet firmware, the pneumatic cylinder is rolled down the first rollers, which move the sleeve from the rolls to be captured by the rod interceptor levers, then the lock and the front head will be folded, the outstanding and sleeve rollers are reduced at high speed. At high speed is issued for a stubborn head to rolling for firmware .
After the firmware of the sleeve, the roller is transported to the mobile stop. Further, the sleeve moves the chain conveyor to the input side of the continuous mill. After the conveyor of the sleeve on the inclined grid rolls to the dispenser, which delaying the sleeve before the input side of the continuous mill. Under the guides of the inclined lattice there is a pocket for collecting defective sleeves. With an inclined grille, the sleeve is reset into the receiving chute of a continuous mill with clips. At this time, a long mandrel is introduced into the sleeve with one pair of friction rollers. Upon reaching the forward end of the front end of the sleeve, the clamp of the sleeve is released, two pairs of pulling rollers and a gilware with a mandrel are set to a continuous mill. At the same time, the speed of rotation of pulling rollers mandrels and pulling rollers The sleeve is calculated in such a way that at the time of capturing the sleeve of the first curtain of the continuous mill, the extension of the mandrel from the sleeve was 2.5-3.0 m. In this regard, the linear speed of pulling rollers must be 2.25-2.5 times higher than the linear speed of pulling sleeves.
Rolted pipes with mandrels are alternately transmitted to the axis of one of the dignuminous parts. The head of the mandrel passes through the liner of the extractor and is captured by the insertion of the grip, and the pipe into the ring of the Luban. When the rim chain moves, it comes out of the pipe and falls on the chain conveyor, which transmits it to a dual rolling rolling, transporting mandrels from both extorters in a cooling bath.
After removing the mandrel, the rough tube enters the saws for trimming the rear spool end.
After induction heating, the pipe is set in a reducing mill having twenty-four trilk cells. In a reduction mill, the number of operating cells is determined depending on the size of the size of the rolled pipes (from 9 to 24 cells), and the crates are excluded, starting from 22 to the side of the decrease in the cell numbers. Cage 23 and 24 participate in all rolling programs.
During rolling, the rolls are continuously cooled with water. When the pipes are moving along the cooling table in each link it should be no more than one pipe. When rolling the permal hot-deformed pipes, intended for the manufacture of pump-compressor pipes of the strength group "K" from steel grade 37g2c after a reduction mill, an accelerated adjustable cooling of pipes in sprayers is carried out.
The flow rate of pipes through the sprayer should be stabilized at the speed of the reducing mill. Control over the speed stabilization is carried out by the operator according to the operational instruction.
After the reduction of the pipe is entered onto a cooling table with walking beams where they are cooled.
Behind the cooling table, the pipes are collected in single-layer packets for cutting ends and cutting on measuring lengths on the saws of cold cutting.
The finished pipes arrive at the OTV inspection table, after inspection, the pipes are linked to packages and sent to the warehouse of finished products.
2.3 Justification of design solutions
With a magnificent reduction of pipes with tension on the PPP, there is a significant longitudinal difference of pipe ends. The cause of the terminal pavement of pipes is the instability of axial tensions in nonstationary deformation modes when filling and released mill working cells with metal. End plots are reduced under conditions of significantly smaller longitudinal tensile stresses than the main (average) part of the pipe. Increasing the wall thickness on end areas, superior to permissible deviations, makes it necessary to remove the considerable part of the finished pipe
The norms of the terminal cutting of the reduced pipes on the TPA-80 of OJSC "Cruscharovavod" are shown in Table. 2.14.
Table 2.14 - Edings of pipes of pipes on TPA-80 OJSC "Crocker Supplies"
2.4 Justification of design solutions
With a magnificent reduction of pipes with tension on the PPP, there is a significant longitudinal difference of pipe ends. The cause of the terminal pavement of pipes is the instability of axial tensions in nonstationary deformation modes when filling and released mill working cells with metal. End plots are reduced under conditions of significantly smaller longitudinal tensile stresses than the main (average) part of the pipe. Increasing the wall thickness at end areas, superior to permissible deviations, makes it necessary to remove a significant part of the finished pipe.
The norms of the terminal cutting of the reduced pipes on the TPA-80 of OJSC "Cruscharovavod" are shown in Table. 2.15.
Table 2.15 - Cutting the ends of pipes on TPA-80 OJSC "Crossow
where the pc-front thickened end of the pipe; Zk- Rear thickened pipe end.
Approximately annual metal loss in the thickened ends of the pipes in the T-3 workshop of OJSC "Crossavod" make up 3000 tons. When cutting the length and weight of the circumcised thickened ends of pipes by 25%, the annual profit increase will be about 20 million rubles. In addition, the cost savings will be saved to the tool saw packet cutting, electricity, etc.
In addition, in the production of an alplaying blank for draped workshops, it is possible to reduce the longitudinal difference in pipes, saved metal due to a decrease in longitudinal partitions to use for further increase in the production of hot rolled and cold-deformed pipes.
Continuous pipe rolling units are the most promising high-performance plants for the production of hot-rolled seamless pipes of the appropriate sorting.
The aggregates include the firmware, continuous canopy and reduction stretching mills. Continuity of the technological process, automation of all transport operations, the large length of rolled pipes provide high performance, good quality pipes over the surface and geometric sizes
In recent decades, intensive development of pipe production by the method of continuous rolling: built and put into operation (in "Italy, France, USA, Argentina) were built, reconstructed (in Japan) continuous rolling shops, equipment for new workshops (in the PRC) was developed, developed And projects for the construction of workshops (in France, Canada, USA, Japan, Mexico) are introduced.
Compared to the aggregates put into operation in the 60s, new mills have significant differences: they are mainly manufactured by the pipes of the oil range, and in connection with the workshops, large areas are built to finish these pipes, including equipment for disembarking them ends, heat treatment, cutting pipes, couplom production, etc.; The range of pipe sizes was significantly expanded: the maximum diameter increased from 168 to 340 mm, the wall thickness is from 16 to 30 mm, which became possible due to the development of the rolling process on the long mandrel, moving at adjustable speed, instead of the floating. The new pipe rolling aggregates use continuous-liting blank (square and round), which ensured a significant improvement in the technical and economic indicators of their work.
An annular ovens (TPA 48-340, Italy) are still widely used to heat the blanks (TPA 48-340, Italy), along with this, begin to use ovens with a walking side (TPA 27-127, France, TPA 33-194, Japan). In all cases, the high performance of the modern unit is ensured by setting one furnace large, unit power (performance up to 250 t / h). For heating pipes before the reduction (calibration), ovens with walking beams are used.
The main mill for obtaining the sleeves continues to remain a two-color steel rolling mill, the design of which is improved, for example, by replacing the stationary lines with drive guide disks. In the case of the use of square billets, the screw rolling mill in the technical line is preceded by either a pressing mill (TPA 48-340 in Italy, TPA 33-194 in Japan), or a mill for the calibration of faces and a press for the deep bracket (TPA 60-245, France).
One of the main directions for the further development of a continuous rolling method is the use of mandrels moving at adjustable speed in the rolling process, instead of floating. With the help of a special mechanism that develops a retention force of 1600-3500 kN, a mandrel is set to a certain speed (0.3-2.0 m / s), which is supported either until the pipe is completely removed from the mandrel during the rolling process (held by the mandrel) or to a certain The moment starting from which the certificate moves as a floating (partially retained mandrel). Each of these methods can be used in the production of pipes of a certain diameter. So, for small-diameter pipes, the method of rolling on a floating mandrel, mean (up to 200 mm) - on partially held, large (up to 340 mm or more) - on the held one.
Application on continuous mills mandrels moving at adjustable speed (held, partially held) in return for floating provides a significant expansion of the sorting, an increase in pipe length and increase their accuracy. Represent the interest of separate design solutions; For example, the use of a rod of the firmware mill as a partially retained mandrel of a continuous mill (TPA 27-127, France), extralated entry of mandrel in the sleeve (TPA 33-194, Japan).
New aggregates are equipped with modern reduction and calibration mills, and one of these mills is most often used. Cooling tables are designed to receive pipes after reduction without pre-cutting.
Evaluating the current general state of pipe mill automation, the following features can be noted.
Transport operations related to the movement of rolled and tool in the unit are automated quite fully using traditional local (mainly non-contact) automation devices. Based on such devices and it was possible to introduce high-performance units with a continuous and discrete-continuous technological process.
Actually, technological processes and even individual operations on pipe mills are automated so far, it is clearly not enough and in this part, their level of automation is noticeably inferior to the achieved, for example, in the area of \u200b\u200bcontinuous leafy mills. If the use of control computing machines (UMM) for leafy mills has become a practically widely recognized standard, then for pipes, examples are still single in Russia, although there are currently the development and implementation of ACS TP and ASUP has become the norm. In the meantime, on a number of pipe mills, in our country there are mainly examples of the industrial implementation of individual subsystems of automated control technological processes using specialized devices made using semiconductor logic and elements of computing technology.
The marked state is due to two circumstances. On the one hand, until recently, the requirements for quality, and above all, to the stability of pipe sizes, satisfied relatively simple funds (in particular, rational structures of equipment of the mill). These conditions did not stimulate more perfect and, naturally, more complex developments, for example, using relatively costly and not always sufficiently reliable UMM. On the other hand, the use of special non-standard automation techniques was possible only for simpler and less effective tasks, while there were significant costs of time and means for the development and manufacture, which did not contribute to the progress in the region under consideration.
However, increasing modern requirements for pipe production, including the quality of pipes, cannot be satisfied with traditional solutions. Moreover, as practice shows, a significant proportion of efforts to satisfy these requirements are on automation, and, at present, it is necessary to automatically change these modes during rolling pipes.
Modern achievements in the field of electric drive management and various automation technical means, primarily in the field of mini-computer and microprocessor equipment, make it possible to radically improve the automation of pipe mills and aggregates, overcome various production and economic restrictions.
The use of modern automation technical means implies simultaneous increase in the requirements for the correctness of the tasks and the choice of ways to solve them, and in particular - to the choice of the most effective ways to influence technological processes, the solution of this task may be facilitated by analyzing the existing most effective technical solutions for pipe mill automation.
Studies of continuous pipe rolling units as automation facilities show that there are substantial reserves of further enhancement of technical and economic indicators by automating the technological process of rolling pipes on these aggregates.
When rolling in a continuous mill on a long floating mandrel, the terminal longitudinal difference is also guided. The wall thickness of the rear ends of the draft pipes is greater than the middle of 0.2-0.3 mm. The length of the rear end with a thickened wall is equal to 2-3 interlineal gaps. The thickening of the wall is accompanied by an increase in the diameter on the site, distinguished on one intercentrous gap from the rear end of the pipe. Due to transient modes, the thickness of the front ends wall is 0.05-0.1 mm less than the middle, when rolling with the tension of the wall of the front ends of the pipes is also thickened. The longitudinal difference in the black tubes is maintained upon subsequent reduction and leads to an increase in the length of the rear cut of the thickened ends of the finished pipes.
When rolling in reduction stretching mills, the wall of the pipe ends is thickened due to a decrease in tension compared to the installed mode, which occurs only when filling 3-4 centes. The ends of the pipes with thickened by the wall are cut off, and the associated metal waste causes the bulk share of the total consumable coefficient on the unit.
The overall nature of the longitudinal pavement of pipes after a continuous mill is almost completely transferred to finished pipes. This is convinced by the results of rolling pipes with dimensions of 109 x 4.07 - 60 mm at five tension modes on a reduction mill of installation 30-102 yuts. In the process of experiment at each high-speed mode, 10 pipes were selected, the terminal sections of which were cut at 10 parts of 250 mm long, and three nozzles were cut from the middle, located at a distance of 10, 20 and 30 m from the front end. After the thickness of the wall thickness on the instrument, deciphering the vapor diagrams and the averaging of the data were constructed graphic dependencies, presented in Fig. 54.
Thus, the marked components of the overall work of pipes have a significant impact on the technical and economic indicators of the operation of continuous units, are associated with the physical characteristics of rolling processes in continuous and reduction mills and can be eliminated or significantly reduced only by special automatic systems that change the setting of the mill in the process rolling pipe. The legitarious nature of these components of the pavement allows you to use the software principle of management at the heart of such systems.
Known others technical solutions Tasks for reducing end waste during reduction using automatic process control systems for rolling pipes in a reduction mill with an individual actuator (FRG patents No. 1602181 and the UK 1274698). Due to changes in the speeds of rolls, when rolling the front and rear ends of pipes, the additional tension force creates, which leads to a decrease in the terminal longitudinal partitions. There is information that such software correction systems of the speed of the main drives of the reduction mill operate on seven foreign pipe rolling aggregates, including two units with continuous mills in Mülgeym (Germany). The aggregates are delivered by Mannesmann (Germany).
The second unit was powered in 1972 and includes a 28-centered reduction mill with individual drives, equipped with speed correction system. Changes in speeds when passing the ends of pipes are carried out in the first ten cells, stepwise, as additives to the operating value of the speed. The maximum change in speed takes place on the crate number 1, the minimum - on the crate number 10. As the sensors of the position of the pipe ends in the mill, giving commands to change the speed, photorele are used. In accordance with the adopted speed correction scheme, the nutrition of the individual actuators of the first ten cells is carried out on an anti-paramele reversing scheme, subsequent cells - by non-experimental scheme. It is noted that the correction of the speeds of the reduction mill drives makes it possible to increase the yield of a suitable one by the unit by 2.5% with a mixed production program. With increasing degree of reduction in diameter, this effect increases.
There is similar information about the equipment of twenty cereal reducing mill in Spain, the speed correction system. Changes to speeds by performing the first 12 cells. In this regard, various power supply schemes are also provided.
It should be noted that the equipment of the reduction mills in the composition of continuous pipe-rolling aggregates of the speed correction system does not allow to fully solve the problem of reducing end waste during the reduction. The effectiveness of such systems should decrease with a decrease in the degree of reduction in diameter.
Systems of the software department technological process are the most simple in implementation and give a large economic effect. However, with their help, it is possible to increase the accuracy of the sizes of pipes only by reducing one of the three components - longitudinal pavement. As studies show, the main share in the general scatter of the thickness of the walls of finished pipes (about 50%) falls on transverse difference. The fluctuations in the medium thicknesses of the pipe walls in the batches is about 20% of the total scatter.
Currently, the decrease in transverse variation is possible only by improving the technological process of rolling pipes on the mills that are part of the unit. Examples of applying automatic systems for these purposes are unknown.
Stabilization of medium thicknesses of the walls of pipes in batches is possible both by improving the rolling technology, the design of the cells and the electric drive, and through automatic process control systems. Reducing the scatter of thicknesses of the walls of pipes in the batch allows you to significantly increase the productivity of the aggregates and reduce the metal consumption due to rolling in the field of minus tolerances.
Unlike software systems, systems intended to stabilize the average thicknesses of the walls of pipes should include in their composition sensors of control of the geometric sizes of pipes.
Technical proposals are known to equip reduction mills by automatic stabilization of pipe wall thickness. The structure of the systems does not depend on the type of unit, which contains a reduction mill.
A complex of process control systems for pipe rolling in continuous and reduction mills intended to reduce end waste during reduction and increasing the accuracy of pipes by reducing the longitudinal pavement and the scatter of the average wall thicknesses forms the ACS of the aggregate.
The use of computers to control the production and automation of the technological process of rolling pipes was first implemented on a continuous pipe rolling unit 26-114 in Mülgeym.
The unit is designed for rolling with a pipeline of 26-114 mm, the thickness of the wall is 2.6-12.5 mm. The aggregate includes a ring furnace, two firmware mills, a 9-cenoe continuous mill and a 24-core reduction mill with an individual drive from 200 kW engines.
The second unit with a continuous mill in Mülgeym, fastened in 1972, is equipped with a more powerful computer, to which wider functions are assigned. The unit is designed to rolling pipes with a diameter of up to 139 mm, the wall thickness is up to 20 mm and consists of a firmware mill, eight cable continuous mill and twenty cereal reducing mill with an individual drive.
The continuous pipe rolling unit in the UK, broken in 1969, is also equipped with a computer that is used to plan the unit loading and as an information system continuously controls the parameters of the rolled and tool. Control quality of pipes and blanks, as well as the accuracy of settings of the mill, is carried out at all stages of the technological process. Information from each mill enters the computer for processing, after which it is issued for mills for operational management.
In a word, the task of automating rolling processes is trying to solve in many countries, incl. and ours. For development mathematical model Continuous Mattas Management It is necessary to know the effect of the specified technological parameters to the accuracy of the finished pipes, for this it is necessary to consider the features of continuous rolling.
A feature of the reduction of pipes with tension is higher product quality as a result of the formation of smaller transverse variation, unlike rolling without tension, as well as the possibility of obtaining small diameters. However, with this rolling, an increased longitudinal difference is observed at the ends of the pipes. Thickened ends during reduction with tension are formed due to the fact that the front and rear ends of the pipe when passing through the core are not exposed to the full effect of tension.
The tension is characterized by the magnitude of the stretching voltage in the pipe (x). Most complete characteristic It is a plastic tension coefficient that represents the ratio of the longitudinal tensile pipe stress to the metal deformation resistance in the crate.
Usually, the reducing mill is tuned in such a way that the plastic tension coefficient in medium-sized cells is uniformly distributed. In the first and recent cells, there is an increase and decrease in tension.
To intensify the reduction process and obtaining thin-walled pipes, it is important to know the maximum tension that can be created in a reduction mill. The maximum value of the plastic tension coefficient in the mill (z max) is limited to two factors: pulling the ability of rolls and the conditions of breaking the pipe in the mill. As a result of the research, it was established that with the total pipe compression in a mill to 50-55%, Z MAX is limited to the pulling ability of the rolls.
The T-3 workshop, together with EFI, Vnipi "Tyazhpromelektroproekt" and the enterprise "ASK" created the basis of the ACS-TP system on the TPA-80 unit. Currently, the following components of this system are functioning: Uzn-N, Uzn-p, Ethernet communication line, all arms.
3.2 Calculation Table Rolling
The main principle of constructing the technological process in modern installations is to obtain on a continuous mill of the pipes of one permanent diameter, which allows the use of a blank and a sleeve is also a permanent diameter. Obtaining the pipes of the required diameter is ensured by the reduction. Such a work system makes it much easier and simplifies the setting of the mill, reduces the tool park and, most importantly, it allows you to maintain high performance of the entire unit even when rolling pipes of the minimum (after reduction) diameter.
The rolling table is counting against the rolling stroke according to the method described in. The outer diameter of the pipe after the reduction is determined by the size of the last pair of rolls.
D p 3 \u003d (1,010..1,015) * d o \u003d 1.01 * 33.7 \u003d 34 mm
where D p is the finished pipe after the reducing mill.
Since after a continuous mill, a pipe of one diameter comes out, then we accept D H \u003d 94 mm. In continuous mills, the roll calibration ensures the obtainment in the last steam rolls of the inner diameter of the pipe larger than 1-2 mm diameter, so that the mandrel diameter will be equal to:
H \u003d D H - (1..2) \u003d D H -2S N -2 \u003d 94-2 * 3.2-2 \u003d 85.6 mm.
We adopt the diameter of the mandrel equal to 85 mm.
The inner diameter of the sleeve must provide free administration of the mandrel and takes 5-10 mm larger than the diameter of the mandrel
d r \u003d n + (5..10) \u003d 85 + 10 \u003d 95 mm.
The wall of the sleeve accept:
S r \u003d s H + (11..14) \u003d 3.2 + 11.8 \u003d 15 mm.
The outer diameter of the sleeves is determined based on the size of the inner diameter and the wall thickness:
D r \u003d D g + 2s g \u003d 95 + 2 * 15 \u003d 125 mm.
The diameter of the used billet D З \u003d 120 mm.
The diameter of the mandrel of the firmware is selected taking into account the magnitude of the rolling, i.e. Lifting the inner diameter of the sleeve constituting from 3% to 7% of the inner diameter:
N \u003d (0.92 ... 0.97) D g \u003d 0.93 * 95 \u003d 88 mm.
The coefficients of drawing for the firmware, continuous and reduction mills are determined by formulas:
,
Common hood coefficient is:
Similarly, a rolling table for pipes with a size of 48.3 × 4.0 mm and 60.3 × 5,0mm is calculated.
The rolling table is presented in Table. 3.1.
| The size of finished pipes, mm | Diameter of the workpiece, mm | Firmware Stan. | Continuous Stan. | Reducing Stan. | Common hood coefficient | ||||||||||
| Outside diameter | Wall thickness | Size of the sleeve, mm | Mandrel diameter, mm | Extrase coefficient | Pipe sizes, mm | Mandrel diameter, mm | Extrase coefficient | Pipe size, mm | Number of cells | Extrase coefficient | |||||
| Diameter | Wall thickness | Diameter | Wall thickness | Diameter | Wall thickness | ||||||||||
| 33,7 | 3,2 | 120 | 125 | 15 | 88 | 2,20 | 94 | 3,2 | 85 | 5,68 | 34 | 3,2 | 24 | 2,9 | 36,24 |
| 48,3 | 4,0 | 120 | 125 | 15 | 86 | 2,2 | 94 | 4,0 | 84 | 4,54 | 48,6 | 4,5 | 16 | 1,94 | 19,38 |
| 60,3 | 5,0 | 120 | 125 | 18 | 83 | 1,89 | 94 | 5,0 | 82 | 4,46 | 61,2 | 5,0 | 12 | 1,52 | 12,81 |
3.3 Calibration of reducing mill rolls
Calibration of rolls is important part of Calculation of the mode of operation of the mill. It largely determines the quality of the pipes, the durability of the tool, the distribution of loads in working cells and drive.
Calibration calculation of rolls includes:
a) the distribution of private deformations in the cities of the mill and counting the average diameters of calibers;
b) Determination of the size of the valve calibers.
3.3.1 Distribution of private deformations
According to the nature of the changes in private deformations of the cage of the reduction mill can be divided into three groups: the head at the beginning of the mill, in which the compresses are intensively increasing in the course of rolling; calibrating (at the end of the mill), in which deformations decrease to minimum meaning, and a group of centes between them (middle), in which private deformations are maximal or close to them.
When rolling pipes with a tension of the size of private deformations, it is taken on the basis of the condition of the stability of the pipe profile with the magnitude of the plastic tension that provides a predetermined pipe.
The coefficient of general plastic tension can be determined by the formula:
,
where - axial and tangential deformations taken in logarithmic form; The value is determined in the case of trivial caliber by the formula
T \u003d. 
,
where (S / D) Cp is the mean ratio of the wall thickness to the diameter for the period of strain of the pipe in the mill; K-coefficient taking into account the change in the degree of thickness of the pipe.
,
,
where M is the value of the total deformation of the pipe in diameter.
.
,
.
The magnitude of the critical private compression with this coefficient of plastic tension, according to, can reach 6% in the second crate, 7.5% in the third cage and 10% in the fourth cage. In the first crates it is recommended to receive in the range of 2.5-3%. However, to ensure a stable capture, the magnitude of the compression is usually reduced.
In the premeditone and fines of the mill, the compression is also reduced, but to reduce loads on the rolls and increase the accuracy of finished pipes. In the last cage of the calibrating group, the compression is taken equal to zero, the penultimate-up to 0.2 of the compression in the last cage of the middle group.
IN medium group Celes are practiced a uniform and uneven distribution of private deformations. With a uniform distribution of compression in all cells of this group, they are permanent. The uneven distribution of private deformations may have several options and be characterized by the following laws:
compression in the middle group is proportionally reduced from the first cells to the latter - the falling mode;
in several first cells of the middle group, private deformations are reduced, and the rest are permanent;
compression in the middle group first increase, and then reduce;
in several first cells of the middle group, private deformations are left permanent, and in the rest reduce.
With falling deformation modes in the average group of cells, the differences in the value of rolling power and the load load are reduced, caused by the growth of metal deformation resistance as rolling, due to the decrease in its temperature and increase the deformation rate. It is believed that a decrease in compression by the end of the mill also allows you to improve the quality of the outer surface of the pipes and reduce the transverse difference.
When calculating the calibration of rolls we accept the uniform distribution of compounds.
The magnitudes of private deformations in the mills are shown in Fig. 3.1.
Distribution of compounds
Based on the adopted values \u200b\u200bof private deformations, the average diameters of calibers can be calculated by the formula
.
For the first cage of the mill (i \u003d 1) d i -1 \u003d d 0 \u003d 94 mm, then
mm.
Calculated for this formula, the average diameters of the calibers are shown in Appendix.1.
3.3.2 Determination of the size of the valve calibers
The shape of calibers of trivial braids is shown in Fig. 3.2.
Oval caliber is derived from its radius RC center, shifted relative to the rolling axis by the Eccentricity EXC.
Form of caliber
The values \u200b\u200bof radii and eccentricity of calibers are determined by width and height of calibers by formulas:
To determine the size of the caliber, it is necessary to know the values \u200b\u200bof its semi-axes A and B, and for their definition - the value of the ovality of the caliber
To determine the ovality of the caliber, you can use the formula:
The C power indicator characterizes the possible amount of broadening in caliber. During reduction in trivial cells, q \u003d 1.2 is taken.
The values \u200b\u200bof the caliber semi-axes are determined by the dependences:
where the F-correction coefficient that can be calculated by the approximate formula
We will calculate the size of the caliber according to the above formulas for the first crate.
For other cells, the calculation is made in the same way.
Currently, the roller tone is carried out after installing the rolls to the working cage. The boring is leading on special machines round cutter. The boring circuit is shown in Fig. 3.3.
Fig. 3.3 - Caliber Boring Scheme
To obtain a caliber with predetermined values \u200b\u200bA and B, it is necessary to determine the diameter of the cutter D F and its displacement relative to the plane of the roll axes (parameter x). D F and X are determined by the following mathematically accurate formulas:
For trivial milling angle A is 60 ° .di - the perfect diameter of the rolls, di \u003d 330mm.
Calculated according to the above formulas of the values \u200b\u200bare summarized in Table. 3.2.
Table 3.2 - Calibration of rolls
| Clay number | d, mm. | m,% | a, mm. | b, mm. | r, mm. | e, mm. | D f, mm | X, mm. |
| 1 | 91,17 | 2,0 | 45,60 | 45,50 | 45,80 | 0,37 | 91,50 | 8,11 |
| 2 | 87,07 | 4,5 | 43,60 | 43,40 | 43,80 | 0,35 | 87,40 | 8,00 |
| 3 | 82,71 | 5,0 | 41,40 | 41,20 | 41,60 | 0,33 | 83,00 | 7,87 |
| 4 | 78,58 | 5,0 | 39,30 | 39,20 | 39,50 | 0,32 | 78,80 | 7,73 |
| 5 | 74,65 | 5,0 | 37,40 | 37,20 | 37,50 | 0,3 | 74,90 | 7,59 |
| 6 | 70,92 | 5,0 | 35,50 | 35,40 | 35,70 | 0,28 | 71,20 | 7,45 |
| 7 | 67,37 | 5,0 | 33,70 | 33,60 | 33,90 | 0,27 | 67,60 | 7,32 |
| 8 | 64,00 | 5,0 | 32,00 | 31,90 | 32,20 | 0,26 | 64,20 | 7,18 |
| 9 | 60,80 | 5,0 | 30,40 | 30,30 | 30,60 | 0,24 | 61,00 | 7,04 |
| 10 | 57,76 | 5,0 | 28,90 | 28,80 | 29,00 | 0,23 | 58,00 | 6,90 |
| 11 | 54,87 | 5,0 | 27,50 | 27,40 | 27,60 | 0,22 | 55,10 | 6,76 |
| 12 | 52,13 | 5,0 | 26,10 | 26,00 | 26,20 | 0,21 | 52,30 | 6,62 |
| 13 | 49,52 | 5,0 | 24,80 | 24,70 | 24,90 | 0,2 | 49,70 | 6,48 |
| 14 | 47,05 | 5,0 | 23,60 | 23,50 | 23,70 | 0,19 | 47,20 | 6,35 |
| 15 | 44,70 | 5,0 | 22,40 | 22,30 | 22,50 | 0,18 | 44,80 | 6,21 |
| 16 | 42,46 | 5,0, | 21,30 | 21,20 | 21,30 | 0,17 | 42,60 | 6,08 |
| 17 | 40,34 | 5,0 | 20,20 | 20,10 | 20,30 | 0,16 | 40,50 | 5,94 |
| 18 | 38,32 | 5,0 | 19,20 | 19,10 | 19,30 | 0,15 | 38,50 | 5,81 |
| 19 | 36,40 | 5,0 | 18,20 | 18,10 | 18,30 | 0,15 | 36,50 | 5,69 |
| 20 | 34,77 | 4,5 | 17,40 | 17,30 | 17,50 | 0,14 | 34,90 | 5,57 |
| 21 | 34,07 | 2 | 17,10 | 17,00 | 17,10 | 0,14 | 34,20 | 5,52 |
| 22 | 34,07 | 0 | 17,10 | 17,00 | 17,10 | 0,14 | 34,20 | 5,52 |
| 23 | 34,00 | 0 | 17,00 | 17,00 | 17,00 | 0 | 34,10 | 5,52 |
| 24 | 34,00 | 0 | 17,00 | 17,00 | 17,00 | 0 | 34,10 | 5,52 |
3.4 Speed \u200b\u200bCalculation
The calculation of the high-speed mode of operation of the mill is to determine the numbers of turns of the rolls and on them the numbers of rotation of the engines.
When rolling pipes with tension, a large influence on the change in the wall thickness is the magnitude of plastic tension. In this regard, first of all it is necessary to determine the coefficient of general plastic tension on the mill - z total, which would ensure the obtaining wall. The calculation Z was generally given in clause 3.3.
,
where is the coefficient that takes into account the influence of out-contact zones of deformation:
;
l i - Capture Arc Length:
;
- Capture angle:
;
f is the friction coefficient, we accept f \u003d 0.5; A - the number of rolls in the crate, and \u003d 3.
In the first working cage Z1 \u003d 0. In subsequent cells, it is possible to take z n i -1 \u003d z z.
,
;
;
.
Substituting the above formulas for the first crates to get:
mm;
;
;
;
; ;
mm.
After conducting similar calculations for the second crates, the following results obtained: z p2 \u003d 0.42, s 2 \u003d 3,251mm, z p3 \u003d 0.426, s 3 \u003d 3,252 mm, z p4 \u003d 0.446, s 4 \u003d 3,258mm. On this calculation Z P I, according to the above method, stop, because The Z P2\u003e Z is satisfied.
From the condition of complete slip, we determine the maximum possible tension Z s in the last deforming cage, i.e. z21. In this case, we assume that z p21 \u003d 0.
.
mm;
;
;
Wall thickness in front of the 21st crate, i.e. S 20, you can determine by the formula:
.
;
; ;
mm.
After conducting similar calculations for the 20th cage, the following results obtained: z z20 \u003d 0.357, s 19 \u003d 3,178 mm, z x19 \u003d 0.396, s 18 \u003d 3,168 mm, z x18 \u003d 0.416, s 17 \u003d 3,151mm, z x17 \u003d 0.441, S 16 \u003d 3,151 mm. On this calculation Z P I cease, because The condition z z14\u003e z is satisfied.
The calculated values \u200b\u200bof the thickness of the wall in the mills are given in Table. 2.20.
To determine the numbers of turns of rolls, you need to know the rolling diameters of the rolls. To determine the rolling diameters, you can use the formulas shown in:
, (2)
where d in i is the diameter of the roll on top;
.
If a 
, The calculation of the rolling diameter of the rolls should be carried out by equation (1), if this condition is not executed, then it is necessary to use (2).
The value characterizes the position of the neutral line in the case when it is taken parallel (in terms of) the rolling axis. From the equilibrium condition in the deformation area for this location of the slip areas
,
Covering the input rate of rolling V qq \u003d 1.0 m / s, calculated the number of revolutions of the rolls of the first crate
rpm.
Turns in the rest of the cables found by the formula:
.
The results of the calculation of the speed regime are shown in Table 3.3.
Table 3.3 - Speed \u200b\u200bCalculation Results
| Clay number | S, mm. | DCAT, MM. | n, rpm |
| 1 | 3,223 | 228,26 | 84,824 |
| 2 | 3,251 | 246,184 | 92,917 |
| 3 | 3,252 | 243,973 | 99,446 |
| 4 | 3,258 | 251,308 | 103,482 |
| 5 | 3,255 | 256,536 | 106,61 |
| 6 | 3,255 | 256,832 | 112,618 |
| 7 | 3,255 | 260,901 | 117,272 |
| 8 | 3,255 | 264,804 | 122,283 |
| 9 | 3,254 | 268,486 | 127,671 |
| 10 | 3,254 | 272,004 | 133,378 |
| 11 | 3,254 | 275,339 | 139,48 |
| 12 | 3,253 | 278,504 | 146,046 |
| 13 | 3,253 | 281,536 | 153,015 |
| 14 | 3,252 | 284,382 | 160,487 |
| 15 | 3,252 | 287,105 | 168,405 |
| 16 | 3,251 | 289,69 | 176,93 |
| 17 | 3,250 | 292,131 | 185,998 |
| 18 | 3,250 | 292,049 | 197,469 |
| 19 | 3,192 | 293,011 | 204,24 |
| 20 | 3,193 | 292,912 | 207,322 |
| 21 | 3,21 | 292,36 | 208,121 |
| 22 | 3,15 | 292,36 | 209 |
| 23 | 3,22 | 292,36 | 209 |
| 24 | 3,228 | 292,36 | 209 |
According to Table 3.3. A graph of roller turns is built (Fig. 3.4.).
Rotation rate Valkov
3.5 Power Parameters Rolling
A distinctive feature of the process of reduced rolling compared to other types of longitudinal rolling is the presence of significant in the magnitude of interfloor tensions. The presence of tension has a significant effect on the strength parameters of the rolling - the pressure of the metal on the rolls and moments of rolling.
The metal force on the roll p is the geometric sum of the vertical P in and the horizontal P of the components:
The vertical component of the metal force on the roll is determined by the formula:
,
where p is the average specific pressure of the metal on the roller; L is the length of the deformation zone; d - caliber diameter; A - the number of rolls in the crate.
The horizontal component of the PG is equal to the difference of the efforts of the front and rear tension:
where Z n, z z - the coefficients of the front and rear plastic tension; F p, F s - cross-sectional area of \u200b\u200bthe front and rear ends of the pipe; S S - deformation resistance.
To determine the average specific pressure, it is recommended to use the formula V.P. Anisiform:
.
The moment of rolling (total on the crate) is determined by the formula:
.
The deformation resistance is determined by the formula:
,
where T is the temperature of rolling, ° C; H is the intensity of shift deformation rates, 1 / s; E - relative compression; K 1, K 2, K 3, K 4, K 5 - empirical coefficients, for steel 10: K 1 \u003d 0.885, K 2 \u003d 7.79, K 3 \u003d 0.134, K 4 \u003d 0.164, to 5 \u003d (- 2 ,eight).
The intensity of the rates of deformation is determined by the formula
where L is the degree of deformation of the shift:
t - time of deformation:
The angular speed of the roll is located by the formula:
,
The capacity is by the formula:
In tab. 3.4. The results of calculating the strength parameters of rolling according to the above formulas are presented.
Table 3.4 - Power rolling parameters
| Clay number | s s, MPa | p, KN / m 2 | R, KN. | M, KNM. | N, kW |
| 1 | 116,78 | 10,27 | 16,95 | -1,91 | -16,93 |
| 2 | 154,39 | 9,07 | 25,19 | 2,39 | 23,31 |
| 3 | 162,94 | 9,1 | 21,55 | 2,95 | 30,75 |
| 4 | 169,48 | 9,69 | 22,70 | 3,53 | 38,27 |
| 5 | 167,92 | 9,77 | 20,06 | 2,99 | 33,37 |
| 6 | 169,48 | 9,84 | 19,06 | 3,35 | 39,54 |
| 7 | 171,12 | 10,47 | 18,79 | 3,51 | 43,11 |
| 8 | 173,01 | 11,15 | 18,59 | 3,68 | 47,23 |
| 9 | 175,05 | 11,89 | 18,39 | 3,86 | 51,58 |
| 10 | 176,70 | 12,64 | 18,13 | 4,02 | 56,08 |
| 11 | 178,62 | 13,47 | 17,90 | 4,18 | 61,04 |
| 12 | 180,83 | 14,36 | 17,71 | 4,35 | 66,51 |
| 13 | 182,69 | 15,29 | 17,48 | 4,51 | 72,32 |
| 14 | 184,91 | 16,31 | 17,26 | 4,67 | 78,54 |
| 15 | 186,77 | 17,36 | 16,83 | 4,77 | 84,14 |
| 16 | 189,19 | 18,53 | 16,65 | 4,94 | 91,57 |
| 17 | 191,31 | 19,75 | 16,59 | 5,14 | 100,16 |
| 18 | 193,57 | 22,04 | 18,61 | 6,46 | 133,68 |
| 19 | 194,32 | 26,13 | 15,56 | 4,27 | 91,34 |
| 20 | 161,13 | 24,09 | 11,22 | 2,55 | 55,41 |
| 21 | 134,59 | 22,69 | 8,16 | 1,18 | 33,06 |
| 22 | 175,14 | 15,45 | 7,43 | 0,87 | 25,42 |
| 23 | 180,00 | - | - | - | - |
| 24 | 180,00 | - | - | - | - |
According to Table. 3.4 Constructed graphs of changes in the power parameters of rolling through the centers of the mill (Fig. 3.5., 3.6., 3.7.).
Change medium specific pressure
Changing Metal Efforts on Valley
Changing the moment of rolling
3.6 Study of the influence of transient high-speed reduction modes on the magnitude of the longitudinal surface of the end portions of finished pipes
3.6.1 Description of the calculation algorithm
The study was conducted with the aim of obtaining data on the effect of transient high-speed reduction modes of reduction in the magnitude of the longitudinal surface of the end portions of finished pipes.
Determination of the coefficient of interflowing tension according to the known turns of rolls, i.e. The dependences zn i \u003d f (n i / n i -1) was carried out according to the method of solving the so-called inverse problem, proposed by G.I. Gulyaev, in order to obtain the dependence of the thickness of the wall from the turns of the rolls.
The essence of the technique is as follows.
The established process of pipe reduction can be described by the system of equations reflecting the adherence to the law of constancy of the second volume and equilibrium of the forces in the focus of the deformation:
(3.1.)
In turn, as you know,
Dkat i \u003d j (zz i, zp i, and i),
m i \u003d y (ZZ I, ZP I, B I),
where and i and b i are the values \u200b\u200bthat do not depend on the tension, Ni is a turnover of turns in the i-oh tilt, i is the coefficient of the exhaust in the i-oh crate, DCAT I -Cuting the diameter of the roll in the i-oh crate, ZP I, ZZ I - the coefficients of the front and rear plastic tension.
Considering that ZZ I \u003d ZP I -1 system of equations (3.1.) You can write in general form as follows:
(3.2.)
The system of equations (3.2.) We solve relative to the front and rear plastic tension coefficients by the method of consecutive approximations.
Taking Z1 \u003d 0 Set the value of ZP1 and from the first equation of the system (3.2.) The iteration method is determined by ZP 2, then from the second equation - zp 3, etc., setting the value of ZP 1, you can find such a solution at which zp n \u003d 0 .
Knowing the front and rear plastic tension coefficients, we determine the wall thickness after each cage by the formula:
(3.3.)
where a is the coefficient determined by the formula:
;
;
z i - medium (equivalent) coefficient of plastic tension
.
3.6.2 Research results
Using the results of calculating the calibration of the tool (clause 3.3.) And the speed setting of the mill (rotation rates) with the steady reduction process (clause 3.4.) In the MathCAD 2001 Professional software environment, the system (3.2.) And expressions (3.3.) The purpose of determining the change of wall thickness.
It is possible to reduce the length of the thickened ends by increasing the plastic tension coefficient by changing the turns of the rolls when rolling the terminal pipes.
Currently, the TPA-80 reduction camp has created a system of control mode of continuous displete rolling. This system allows you to dynamically adjust the revolutions of the RRSs of the RRSs when rolling the terminal pipes according to the specified linear dependence. Such regulation of rolls of rolls When rolling the end portions of pipes is called "Wedge of Speeds". Rolls of rolls when rolling end plots of pipes are calculated by the formula:
, (3.4.)
where N i is the turns of the rolls in the i-oh tilt with the steady mode, k I -Choelectile reducing turns of the rolls in%, the I-number of the crate.
The dependence of the turnover coefficient of rolls in this class can be linear
To i \u003d (Fig.3.8.).
Dependence of the coefficient of reducing turns of rolls in the cage from the tilt number.
The source data for the use of this regulation mode are:
The number of cells in which the speed setting changes is limited to the length of the thickened ends (3 ... 6);
The value of reducing turns of rolls in the first cage of the mill is limited by the possibility of an electric drive (0.5 ... 15%).
In this work, to study the impact of the high-speed setting of PPPs on end longitudinal difference, it was assumed that changing the speed setting during the reduction of the front and rear ends of the pipes is carried out in the first 6 cells. The study was carried out by changing the rotation speed in the first cells of the mill with respect to the rolling stated process (varying the angle of tilt forward in Fig. 3.8).
As a result of modeling the filling processes of the PPPs and the exit of the pipe from the pipe of the pipe, the dependences of the wall thickness of the front and rear ends of pipes from the amount of changes in the rotation speed in the first cities are presented in Fig.3.9. and Fig.3.10. For pipes with a size of 33.7x3.2 mm. Most optimal meaning "Wedge of speeds" in terms of minimizing the length of the terminal cutting and "hit" of the wall thickness in the DIN 1629 tolerances field (the tolerance of the wall thickness ± 12.5%) is k 1 \u003d 10-12%.
In fig. 3.11. and fig. 3.12. The dependences of the lengths of the front and rear thickened ends of the finished pipes are given when using the "velocity wedge" (k 1 \u003d 10%) obtained as a result of transient modeling. From the above dependencies, the following conclusion can be made: the use of the "Speed \u200b\u200bWedge" gives a noticeable effect only when rolling the pipes with a diameter of less than 60 mm with a wall thickness less than 5 mm, and with a larger diameter and thickness of the pipe wall, the wall of the wall is not happening to achieve the requirements of the standard.
In fig. 3.13., 3.14., 3.15., The dependences of the length of the front thickened end from the outer diameter of the finished pipes for the values \u200b\u200bof the wall thicknesses of 3.5, 4.0, 5.0 mm, with different values \u200b\u200bof the "speed wedge" (accepted the reducing coefficient K 1 rolls equal to 5%, 10%, 15%).
The dependence of the wall thickness of the front end of the pipe from the size
"Wedge of speeds" for size 33.7x3.2 mm
The dependence of the thickness of the rear end of the pipe from the magnitude of the "wedge of speeds" for the size of 33.7x3.2 mm
The dependence of the length of the front thickened end of the pipe from D and S (at k 1 \u003d 10%)
The dependence of the background of the rear thickened end of the pipe from D and S (at k 1 \u003d 10%)
The dependence of the length of the front thickened end of the pipe from the diameter of the finished pipe (S \u003d 3.5 mm) at different values \u200b\u200bof the "wedge of speeds".
The dependence of the length of the front thickened end of the pipe from the diameter of the finished pipe (S \u003d 4.0 mm) at various values \u200b\u200bof the "wedge of speeds"
The dependence of the length of the front thickened end of the pipe from the diameter of the finished pipe (S \u003d 5.0 mm) with various values \u200b\u200bof the "speed wedge".
Of the above graphs, it can be seen that the greatest effect in terms of reducing the terminal pavement of finished pipes gives a dynamic revolution of RRS rolls within k 1 \u003d 10 ... 15%. There is no intensive change in the "speed wedge" (k 1 \u003d 5%) does not allow you to thin the thickness of the wall of the terminal pipes.
Also when rolling pipes with a wall thickness of 5 mm, the tension arising from the action of the "wedge of speeds" is unable to drown the wall due to the insufficient pulling ability of the rolls. When rolling the pipes with a diameter of more than 60 mm, the hood coefficient in the reduction mill is small, so the thickening of the ends is practically not happening, therefore, the use of the "speed wedge" is impractical.
The analysis of the above graphs showed that the use of "velocity wedge" on a reduction mill TPA-80 OJSC "Crossow" allows to reduce the length of the front thickened end by 30%, the rear thickened end of 25%.
As shown by the calculations Mochalov D.A. For more efficient use of the "Wedge of Speed" to further reduce the terminal cutting, it is necessary to ensure the operation of the first cells in braking mode with the almost complete use of the valve power capabilities due to the use of a more complex non-linear dependence of the turnover coefficient of rolls in this crate from the tilt number. It is necessary to create a scientifically substantiated technique to determine the optimal function k i \u003d f (i).
The development of such an optimal control algorithm of the RRS can serve as the goal for the further development of the UZD-P into a full-fledged ASUTP TPA-80. As the experience of using such ASUTPs, the regulation of the rolls of rolls is shown when rolling the terminal pipes, according to Mannesmann (Carta application package), allows you to reduce the magnitude of the pipe cutting pipes by more than 50%, due to the automatic control system of the process of reduced pipes, which includes A to itself as a mined and measuring subsystem management subsystems and a subsystem for calculating the optimal reduction mode and the management of the process in real time.
4. Technical and Economic Justification of the Project
4.1 Essence of the planned event
This project proposes the introduction of the optimal high-speed rolling mode on a reduction-stretching mill. Due to this event, it is planned to reduce the consumable metal coefficient, and due to the reduction of the length of the sliced \u200b\u200bthickened ends of the finished pipes, an increase in production of 80 tons per month is expected on average.
Capital investments necessary for the implementation of this project make up 0 rubles.
Project financing can be implemented under the "Current Repair" article, cost estimates. You can implement the project within one day.
4.2 Calculation of production costs
Calculation of cost 1T. Products with existing cropping norms of thickened pipe ends is given in Table. 4.1.
Project Calculation is given in Table. 4.2. Since the result of the project implementation is not an increase in production, the recalculation of the flow rate values \u200b\u200bfor the redistribution in the design calculation is not carried out. The profitability of the project is to reduce costs by reducing waste on cropping. Crop reduces due to reduction of the consumable metal coefficient.
4.3 Calculation of project indicators
The calculation of the project indicators is made on the basis of the cost calculation given in Table. 4.2.
Savings from reducing cost per year:
EG \u003d (C 0 -C P) * V PR \u003d (12200,509-12091,127) * 110123.01 \u003d 12045475,08p.
Profit on the report:
PR 0 \u003d (P-C 0) * V from \u003d (19600-12200,509) * 109123.01 \u003d 807454730,39Р.
Profit on the project:
Pr n \u003d (p-s n) * v \u003d (19600-12091,127) * 110123.01 \u003d 826899696.5.
The increase in profits will be:
PR \u003d PR P-PR 0 \u003d 826899696,5-807454730,39 \u003d 19444966,11.
Profitability of products was:
Profitability of project products:
The cash flow on the report and the project is presented in Table 4.3. and 4.4., respectively.
Table 4.1 - Calculation of the cost of 1 tons of rental in the workshop T-3 OJSC "Crossow
| P / P. | Article costs | number | Price 1 ton | Sum |
| 1 | 2 | 3 | 4 | 5 |
| I. | Posted in redistribution: 1. Preparation, t / t; 2. Waste, t / t: circuit substandard; |
|||
| I I. | Peredcel expenses 2. Energy costs: electricity power, kW / h couples for production, Gkal technical water, TM 3 air compressed, TM 3 current water, TM 3 tM 3, TM 3 3. Auxiliary materials 7. Replaceable equipment 10. Overhaul 11. Work of transport workshops 12. Other workshop costs Total traffic expenses |
|||
| Sh | Hosteranvian expenses |
Table 4.2 - Project Calculation of Cost 1 tons of rolled
| P / P. | Article costs | number | Price 1 ton | Sum |
| I. | Posted in redistribution: 1. Preparation, t / t; 2. Waste, t / t: circuit substandard; Total specified in the redistribution of waste and marriage |
|||
| P | Peredcel expenses 1. Technological fuel (natural gas), here 2. Energy costs: electricity power, kW / h couples for production, Gkal technical water, TM 3 air compressed, TM 3 current water, TM 3 tM 3, TM 3 3. Auxiliary materials 4. The main salary of production workers 5. Additional salary of production workers 6. Social deductions 7. Replaceable equipment 8. Maintenance and maintenance of fixed assets 9. Depreciation of fixed assets 10. Overhaul 11. Work of transport workshops 12. Other workshop costs Total traffic expenses |
|||
| Sh | Hosteranvian expenses TOTAL PRODUCTION COST |
|||
| IV | Exproductive expenses Total total cost |
Improving the technological process will affect the technical and economic indicators of the enterprise activities as follows: the profitability of production of products by 1.45% will increase, savings from lower cost will amount to 12 million rubles. a year that will entail profit growth.
Table 4.3 - Cash flow by report
Cash flows |
Of the year | ||||
| 1 | 2 | 3 | 4 | 5 | |
| A. Cash inflow: | |||||
| - production volume, tn | |||||
| - Product price, rub. | |||||
| Total influx | |||||
| B. Cash outflow: | |||||
| - Operational costs | |||||
| -Nalog on profits | 193789135,29 | ||||
Total outflow: |
1521432951,34 | 1521432951,34 | 1521432951,34 | 1521432951,34 | 1521432951,34 |
| Pure cash flow (AA-b) | |||||
Coeff. Inversion |
0,8 | 0,64 | 0,512 | 0,41 | 0,328 |
| E \u003d 0.25. | |||||
| 493902383,46 | 889024290,22 | 1205121815,64 | 1457999835,97 | 1457999835,97 | |
Table 4.4 - Cash flow by project
| Cash flows | Of the year | ||||
| 1 | 2 | 3 | 4 | 5 | |
| A. Cash inflow: | |||||
| - production volume, tn | |||||
| - Product price, rub. | |||||
| - Revenue from sales, rub. | |||||
| Total influx | |||||
| B. Cash outflow: | |||||
| - Operational costs | |||||
| -Nalog on profits | |||||
| Total outflow: | 1526220795,63 | 1526220795,63 | 1526220795,63 | 1526220795,63 | 1526220795,63 |
| Pure cash flow (AA-b) | 632190135,03 | 632190135,03 | 632190135,03 | ||
Coeff. Inversion |
0,8 | 0,64 | 0,512 | 0,41 | 0,328 |
| E \u003d 0.25. | |||||
| Discounted stream (AA-b) * to invest | |||||
| CDD cumulative cash flow | |||||
The financial profile of the project is presented in Fig.4.1. According to the graphs shown in Fig. 4.1. The cumulative Chdd project exceeds the planned indicator, which indicates the unconditional profitability of the project. Cumulative Chdd, calculated for the project being introduced, from the first year is a positive value, since the project did not require capital investments.
Financial project profile
The break-even point is calculated by the formula:
The break-even point characterizes the minimum volume of products at which the losses end, and the first profit appears.
In tab. 4.5. The data is presented to calculate variables and constant costs.
Under the reporting data, the amount of variable costs per unit of production is zoig \u003d 11212.8., The amount of constant cost per unit of production is post \u003d 987.7. The amount of constant costs for the entire volume of the report on the report is 107780796,98.
According to the project data, the amount of variable costs z per \u003d 11103.5p., The amount of constant costs of post \u003d 987.7. The amount of constant costs for the entire volume of the report on the report is 108768496,98.
Table 4.5 - the proportion of constant costs in the structure of the planned and project cost
| P / P. | Article costs | Amount according to plan, rub. | The amount of the project, rub. |
The share of constant costs in the structure of expenses on the redistribution,% |
| 1 | 2 | 3 | 4 | 5 |
| 1 | Peredcel expenses 1. Technological fuel (natural gas), here 2. Energy costs: electricity power, kW / h couples for production, Gkal technical water, TM 3 air compressed, TM 3 current water, TM 3 tM 3, TM 3 3. Auxiliary materials 4. The main salary of production workers 5. Additional salary of production workers 6. Social deductions 7. Replaceable equipment 8. Current repair and maintenance of fixed assets 9. Depreciation of fixed assets 10. Overhaul 11. Work of transport workshops 12. Other workshop costs Total traffic expenses |
|||
| 2 | Hosteranvian expenses TOTAL PRODUCTION COST |
100 | ||
| 3 | Exproductive expenses Total total cost |
100 |
Under the reporting data, the break-even point is:
TB OT 
t.
By project, the break-even point is:
TB PR 
t.
In tab. 4.6. Calculation of revenues and all types of costs for the production of sales products needed to determine the break-even point. Graphs of calculating the break-even point of the report and the project are presented in Fig.4.2. and Fig.4.3. respectively.
Table 4.6 - Data for calculating the break-even point
Calculation of the break-even point of the report
Calculation of the break-even point of the project
As a result, it can be concluded that the event proposed in the project will reduce the cost of the product manufactured by 1.45% by reducing variable costs, which contributes to an increase in profits by 19.5 million rubles. With an annual production of 110123.01 tons. The result of the project is the increase in cumulative net discounted income compared with the planned value in the period under review. Also positive Moment It is a decrease in break-even threshold from 12.85 thousand tons to 12.8 thousand tons.
Table 4.7 - Technical and Economic Indicators of the Project
| No. p / p | Indicator | Report | Project | Deviation | |
| Absolute | % | ||||
| 1 | Production volume: in physical terms, t in value terms, thousand rubles. |
||||
| 2 | The cost of the main production facilities, thousand rubles. | 6775032 | 6775032 | 0 | 0 |
| 3 | Common costs (full cost): total release, thousand rubles. units of products, rub. |
||||
| 4 | Profitability of products,% | 60,65 | 62,1 | 1,45 | 2,33 |
| 5 | Clean discounted income, ChDD | 1700,136 | |||
| 6 | Total investment, thousand rubles. | 0 | |||
| 7 | Reference: break-even point TB, T, discount rate value F, internal yield rate of the GNI maximum cash outflow K, thousand rubles. |
||||
Conclusion
This diploma project has developed a general-purpose pipe production technology for DIN 1629. The paper discusses the possibility of a decrease in the length of the thickened ends generated during the rolling on the reducing mill, due to the change in the high-speed settings of the mill when rolling the terminal sections of the pipe using the capabilities of the UZD-P system. As the calculations showed the decrease in the length of the thickened ends can reach 50%.
Economic calculations have shown that the use of the proposed rolling modes will reduce the cost of a unit of products by 1.45%. This, while maintaining existing production volumes, will allow an increase in profit by 20 million rubles in the first year.
1. Anuriev V.I. "Directory of Designer-Machine Builder" in 3 volumes, Volume 1 - M. "Mechanical Engineering" 1980 - 728 p.
2. Anuriev V.I. "Directory of Designer-Machine Builder" in 3 volumes, Volume 2 - M. "Mechanical Engineering" 1980 - 559 p.
3. Anuryev V.I. "Directory of Designer-Machine Builder" in 3 volumes, Volume 3 - M. Mechanical Engineering 1980 - 557 p.
4. Pavlov Ya.M. "Machine parts". - Leningrad "Mechanical Engineering" 1968 - 450 s.
5. Vasiliev V.I. "Fundamentals of the design of technological equipment of motor transport enterprises" tutorial - Kurgan 1992 - 88 p.
6. Vasiliev V.I. "Basics of designing technological equipment of motor transport enterprises" - Kurgan 1992 - 32 p.
3.2 Calculation Table Rolling
The main principle of constructing the technological process in modern installations is to obtain on a continuous mill of the pipes of one permanent diameter, which allows the use of a blank and a sleeve is also a permanent diameter. Obtaining the pipes of the required diameter is ensured by the reduction. Such a work system makes it much easier and simplifies the setting of the mill, reduces the tool park and, most importantly, it allows you to maintain high performance of the entire unit even when rolling pipes of the minimum (after reduction) diameter.
The rolling table is counting against the rolling stroke according to the method described in. The outer diameter of the pipe after the reduction is determined by the size of the last pair of rolls.
D p 3 \u003d (1,010..1,015) * d o \u003d 1.01 * 33.7 \u003d 34 mm
where D p is the finished pipe after the reducing mill.
Since after a continuous mill, a pipe of one diameter comes out, then we accept D H \u003d 94 mm. In continuous mills, the roll calibration ensures the obtainment in the last steam rolls of the inner diameter of the pipe larger than 1-2 mm diameter, so that the mandrel diameter will be equal to:
H \u003d D H - (1..2) \u003d D H -2S N -2 \u003d 94-2 * 3.2-2 \u003d 85.6 mm.
We adopt the diameter of the mandrel equal to 85 mm.
The inner diameter of the sleeve must provide free administration of the mandrel and takes 5-10 mm larger than the diameter of the mandrel
d r \u003d n + (5..10) \u003d 85 + 10 \u003d 95 mm.
The wall of the sleeve accept:
S r \u003d s H + (11..14) \u003d 3.2 + 11.8 \u003d 15 mm.
The outer diameter of the sleeves is determined based on the size of the inner diameter and the wall thickness:
D r \u003d D g + 2s g \u003d 95 + 2 * 15 \u003d 125 mm.
The diameter of the used billet D З \u003d 120 mm.
The diameter of the mandrel of the firmware is selected taking into account the magnitude of the rolling, i.e. Lifting the inner diameter of the sleeve constituting from 3% to 7% of the inner diameter:
N \u003d (0.92 ... 0.97) D g \u003d 0.93 * 95 \u003d 88 mm.
The coefficients of drawing for the firmware, continuous and reduction mills are determined by formulas:
,
Common hood coefficient is:
Similarly, a rolling table for pipes with a size of 48.3 × 4.0 mm and 60.3 × 5,0mm is calculated.
The rolling table is presented in Table. 3.1.
|
The size of finished pipes, mm |
Diameter of the workpiece, mm |
Firmware Stan. |
Continuous Stan. |
Reducing Stan. |
Common hood coefficient |
||||||||||
|
Outside diameter |
Wall thickness |
Size of the sleeve, mm |
Mandrel diameter, mm |
Extrase coefficient |
Pipe sizes, mm |
Mandrel diameter, mm |
Extrase coefficient |
Pipe size, mm |
Number of cells |
Extrase coefficient |
|||||
|
Wall thickness |
Wall thickness |
Wall thickness |
|||||||||||||
3.3 Calibration of reducing mill rolls
Calibration of rolls is an important part of the calculation of the operation mode. It largely determines the quality of the pipes, the durability of the tool, the distribution of loads in working cells and drive.
Calibration calculation of rolls includes:
the distribution of private deformations in the cities of the mill and counting the average diameters of calibers;
determination of the size of the valve calibers.
3.3.1 Distribution of private deformations
According to the nature of the changes in private deformations of the cage of the reduction mill can be divided into three groups: the head at the beginning of the mill, in which the compresses are intensively increasing in the course of rolling; The calibrating (at the end of the mill), in which the deformations decrease to the minimum value, and the group of the cells between them (the average), in which private deformations are maximal or close to them.
When rolling pipes with a tension of the size of private deformations, it is taken on the basis of the condition of the stability of the pipe profile with the magnitude of the plastic tension that provides a predetermined pipe.
The coefficient of general plastic tension can be determined by the formula:
,
where 
- axial and tangential deformations taken in logarithmic form; The value is determined in the case of trivial caliber by the formula
where (S / D) Cp is the mean ratio of the wall thickness to the diameter for the period of strain of the pipe in the mill; K-coefficient taking into account the change in the degree of thickness of the pipe.
,
,
where M is the value of the total deformation of the pipe in diameter.
.
The magnitude of the critical private compression with this coefficient of plastic tension, according to, can reach 6% in the second crate, 7.5% in the third cage and 10% in the fourth cage. In the first crates it is recommended to receive in the range of 2.5-3%. However, to ensure a stable capture, the magnitude of the compression is usually reduced.
In the premeditone and fines of the mill, the compression is also reduced, but to reduce loads on the rolls and increase the accuracy of finished pipes. In the last cage of the calibrating group, the compression is taken equal to zero, the penultimate-up to 0.2 of the compression in the last cage of the middle group.
In the middle group of cells, the uniform and uneven distribution of private deformations are practiced. With a uniform distribution of compression in all cells of this group, they are permanent. The uneven distribution of private deformations may have several options and be characterized by the following laws:
compression in the middle group is proportionally reduced from the first cells to the latter - the falling mode;
in several first cells of the middle group, private deformations are reduced, and the rest are permanent;
compression in the middle group first increase, and then reduce;
in several first cells of the middle group, private deformations are left permanent, and in the rest reduce.
With falling deformation modes in the average group of cells, the differences in the value of rolling power and the load load are reduced, caused by the growth of metal deformation resistance as rolling, due to the decrease in its temperature and increase the deformation rate. It is believed that a decrease in compression by the end of the mill also allows you to improve the quality of the outer surface of the pipes and reduce the transverse difference.
When calculating the calibration of rolls we accept the uniform distribution of compounds.
The magnitudes of private deformations in the mills are shown in Fig. 3.1.
Distribution of compounds
Based on the adopted values \u200b\u200bof private deformations, the average diameters of calibers can be calculated by formulation pipeand, directly, ... failures) during production Foam concrete. For production Foam concrete applied various ... workers directly related to production Foam concrete, special clothing, ...
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