Designed for the production of axisymmetrical in plan forgings with elements of thin sheets using the hot end rolling method (HFR) from carbon and alloy steels.
The complex can be used in forge shops of machine-building enterprises involved in the production of parts such as disks, flanges, rings, etc.
A modernized complex based on a commercially produced hydraulic press mod. DE2432 is retrofitted with a GTR installation and has a unified control system.
The installation for (GTR) includes two spindles with replaceable tools: an upper non-drive and a lower drive, respectively installed on the slide and on the press table.
The lower spindle with the lower rolling tool is driven into rotation by an individual electric motor through a V-belt and two low-noise gear drives. The upper spindle with the upper rolling tool is equipped with a mechanism for adjusting the angle of inclination relative to the vertical axis of rotation.
When rolling out rotational movement from the lower spindle due to friction forces is transmitted through the deformed workpiece to the upper spindle.
It is possible to complete the installation with means of loading and unloading blanks (semi-finished products).
The technological process of producing forgings using the GTR method by compressing the metal in local contact makes it possible to reduce the rolling force by 5-10 times or more compared to the deformation force on a CGShP or PVShM.
The main feature of the proposed process is the ability to produce products with thin webs with a height-to-diameter ratio of up to 0.03, which is practically unattainable with traditional KPO. When face rolling these products, metal consumption is reduced to 15%, and the labor intensity of machining is reduced to 25%.
Application new technology makes it possible to reduce the weight of the forging, reduce the volume machining and, most importantly, to reduce the force due to local deformation, which makes it possible to replace with such installations a more powerful stamping equipment. The proposed complexes for the production of the mentioned types of forgings will successfully replace traditional equipment: CGShM with a force of 630-1000 tf and partially 1600 tf, as well as PVShM with a MF of 630-1000 kg and partially 2000 kg, having a shockless nature of operation, smaller overall dimensions, weight and cost .
In production conditions, the complex is operated in conjunction with heating means. If necessary, the section can include a press for upsetting the semi-finished product for subsequent rolling.
UDC 621.73
FINITE ELEMENT MODEL FOR CALCULATING THE AMOUNT OF ACCUMULATED STRAIN DURING HOT ROLLING OF RINGS
© 2009 F.V. Grechnikov1, E.V. Aryshensky1, E.D. Beglov2
1 Samara State Aerospace University 2 JSC "Samara Metallurgical Plant"
Received by the editor 02/13/2009
A finite element model has been developed for calculating the degree of accumulated deformation at various stages of deformation of a ring workpiece. A comparison of modeling results and experimental dependencies confirms the adequacy of the model.
Key words: rolling of rings, macrostructure, recrystallization, accumulated deformation, finite element method, model, stiffness matrix, equal-strength inserts.
In the practice of gas turbine engine production, ring parts with multifunctional purpose. These details are subject to high requirements by structure and level mechanical properties. The main method of obtaining ring parts is hot rolling(Fig. 1). A feature of this process is the presence of multiple acts of local deformation of the workpiece while it is in the rolls and the accompanying multiple partial recrystallization in interdeformation pauses, making it difficult to calculate the total (accumulated) deformation during the process.
This leads to the fact that along the cross-section of the workpiece, various degrees of deformation, including critical degrees of deformation, can simultaneously be present. In turn, critical degrees of deformation contribute to the formation of large grains during final recrystallization annealing. At the same time, in places where the deformation has exceeded critical values, a fine-grained structure will form. Thus, heterogeneity of deformation leads to heterogeneity of grain, i.e. structural heterogeneity over the cross-section of parts and a decrease in the level of mechanical properties. To avoid this, it is necessary to know at each stage the amount of accumulated deformation received by the metal both at each local stage of deformation and for the entire rolling period as a whole. In this regard, the purpose of this article is to build mathematical model, allowing you to determine the stress
Grechnikov Fedor Vasilievich, Doctor of Technical Sciences, Professor, Corresponding Member of the Russian Academy of Sciences, Vice-Rector for Academic Affairs. Email: [email protected]. Aryshensky Evgeniy Vladimirovich, graduate student. Email: [email protected].
Beglov Erkin Dzhavdatovich, candidate of technical sciences, leading engineer. Email: [email protected].
formed state and the magnitude of the degree of accumulated deformation.
When developing the finite element model, it was taken into account that, due to symmetry, the structure and properties of the rolled ring are identical for all sections around the circumference. Taking this circumstance into account, the model was built not for the entire ring, but for a segment equal to 6 lengths of the deformation zone. The segment is divided into triangular finite elements, as shown in Fig. 2.
The angle p, which determines the position of the element in the solution area, is found using the following formula.
12 1 ■ Kg
(2YAN + 2YAV), (1)
where YAN, YAB are the outer and inner radii of the ring;
K is the average radius of the ring in 1 revolution.
b is the length of the arc of contact with any of the rolls. To determine it, the formula is used
b 1(2) AN, (2)
Rice. 1. Scheme of the process of hot rolling of rings: 1 - blank, 2 - internal non-drive roll (mandrel), 3 - external drive roll, 4, 5 - guide rollers, 6 - limit switch (diameter control)
where R2 are the radii of the drive and non-drive rolls
A b - absolute compression We first divide the solution area into quadrangular sectors, each of which corresponds to two adjacent triangular elements. There are N rows of sectors in the radial direction and M in the tangential direction. There are 2 ■ N ■ M triangular elements and (M + 1) ■ (N + 1) nodes. The numbering of nodes is shown in Fig. 2. We denote the coordinates of the 1st node along axes 1 and 2 as xc, X"2
World Cup)] NMMM)| ;<3>
1 EVn.+Dn-Dn then!± ^toD
During the calculation process, the coordinates of nodes at any point in the calculation area will change by
relocation of nodes ip, 2. To find ip, 2 we will use the energy method. Consider a separate triangular element 1 with nodes 1, 2, 3 in Fig. 3.
Let us assume that the element is initially not stressed, the nodal forces are equal to 0. Then the forces A, Y, /3 are applied to the corresponding nodes of the element. New config
tion of nodes will have a displacement d11, d12, d, d22, d^, d32. The superscript refers to the element, we will omit it in the future. The first lower index refers to the node, and the second to the coordinate. Potential energy I of the new configuration in relation to the initial one, it is the difference between the energy of the stressed state accumulated in the element u and the work done by the forces /2,/3 on the displacement vector e, .
I=u-Zh=2 |(p + st22£22+^^ Uj-A 1j11 -
Fig 3. Setting boundary conditions in the problem of segment deformation
where е12.....- movements at the nodes of the element
in directions 1,2 respectively;
/p...... /32 - forces under the influence of which
the nodes shift in the direction of 1,2, respectively;
е11 е22 are normal, and е12 are tangential components of the deformation tensor;
y11y22 - normal, y12 - tangential components of the stress tensor.
Integration is carried out over volume ^ (in the case under consideration plane strain - by area element dF). For the convenience of further solution, we present equation (5) in matrix form.
I = - |a -e-eG-e 2
Г = 2\еТШеГ - =
Values of the vector components е = |е„ ■■■ е32|| must be such that the potential energy I has a minimum value:
■- = 0 ; Н1...3, . (7)
After differentiation, in vector form we get:
I -ING)-ё = f. (8)
To understand the notation, ||in||, and ||and|| Let's look again separate element, presented in Fig. 3.
If it is triangular, as in our case, and the stresses in it change linearly, then it is recommended to relate the displacement values of the element nodes and its deformation with the following formula.
X22 X-32 X11 X31 X32 X12 X21 X11
21 Hz 12 22
In matrix form, we write expression (9) as follows:
e = \\B\\ - e. (9 a)
As can be seen from (9) ||in|| expresses changes in the coordinates of the nodes of a triangular element while maintaining its area and connects the movement in its nodes with the accumulated deformation.
In turn ||and|| expresses the relationship between the strain tensor and the stress tensor. Its values are different for the elastic and plastic states. Conclusion ||AND|| for both conditions
can be found in . Its values are given here, and only for the plane strain and the energy approach. Elastic deformation:
1 + V 1- - 2v 1 - 2v
Plastic condition:
)- ее = |И| - ee, (12)
for the elastic part of the deformation, for the plastic part of the deformation.
a11 a11 a11 0 22 ^ a11 012
a22 a11" 0 22 0 22 0 22 a12
a12 a11 a12 0 22 a12 012
where shear modulus O =
8 - characteristic parameter of the elastic-plastic state
This parameter allows us to take into account the dependence of stress on deformation and other process parameters, which are expressed through a relationship of the form
0 = 0(e, e, T, a in c), (17)
where e is the accumulated strain under uniaxial compression (tension);
e - deformation rate; T - temperature;
aoa a, b, c - empirically determined relationships. Dedicated to the search for such relationships
But a large number of research. We used the results for alloys used in rolling gas turbine engine rings.
Let's return to formula (8), which, as is now clear, expresses the relationship between the force in the element, on the one hand, and stress, deformation and displacement, on the other. Having excluded displacements from formula (8), we denote its left side as follows.
Ш = М-|И-B-dF- (18)
Sh is the stiffness matrix. It takes into account all the deformation parameters given above. If this matrix is given for one triangular element, it is called local. The global matrix will be the right-hand side matrix of the system (M++1) of equations, formed as the algebraic sum of the local matrices of each element.
It should be noted that we already know the voltage
For a non-driven roll, in the first half of the gripping arc the forces are directed against the direction of metal movement, in the second - in the direction of movement (Fig. 3, b). For each node in contact with the roll, the direction of the forces is known. P - normal pressure, t = juP - friction force, j - friction coefficient.
Let's consider equation (19), which in expanded form for node 9 will be written as follows (Fig. 3, b).
k17.17 d91 + k17.18 d92 + k17.19 d101 + k17.20 d102 +
K17.21 d111 + k17.22 d112 = f91 =
JP cos (p3 - P sin (p3, (20)
k18.17 d91 + k18.18 d92 + k18.19 d101 + k18.20 d102 +
K18,21 d111 + k18,22d112 = f92 =
P sin (p3 + /uP cos (p3. (21)
When solving equations (20) using the Gaussian method, we take into account the condition of non-penetration of the workpiece material into the non-driven roll:
d91 ■ sin (р3 = d92 ■ cos^3. (22)
This condition will allow us to exclude d92 from the system of equations (19). We carry out this transformation for all equations containing nodes lying on the surface of the non-driven roll.
The rotation speed of the drive roll is known, but the mutual displacement of the metal and roll surfaces is unknown. Let's apply the following technique.
Let's introduce a fictitious layer of elements. Let's show it using the example of an element with nodes 7, 6 (Figure 3a). These units move as if rigidly connected to the roll. The nodes of the metal contact layer 5 (Fig. 3 a) move along the surface of the roll. The element stiffness matrix K is modified using the friction index m. The elements of the stiffness matrix are multiplied by m/m - c. At
m tending to 0, the element becomes more rigid, simulating low friction. When m ^ 1, the “sticking” of the material to the rolls is simulated. The elements do not model the lubricant layer, but they model the action of the lubricant. Each element of the fictitious layer is created at the time of construction of the corresponding real element. The real and fictitious element matrices can be compared and jointly solved in equation (8). The movements of the fictitious units are known, i.e. they move as if rigidly connected to the roll.
Equations (19) for node 5 (Fig. 3 a) will have the following form.
k9 3d 23 + k 9.4d 22 + k9.7 d41 + k9.8 d42 + k9.9 d51 + + k 9.10 d52 + k 9.15 d 81 + k9.16 d82 + k 9.13 d71 + + k 9.14d 72 + k 9.11 d61 + k 9.12 d62 = f51 , (23)
k10.3 d 21 + k10.4d 22 + k10.7 d41 + k10.8 d42 + k10.9 d51 + + k10.10 d 52 + k10.15 d 81 + k10.16 d 82 + k10.13 d71 + + k10,14d72 + k10,11 d61 + k10,12d62 = f52 . (24)
Since the force in node 5 is normal to the surface of the roll, we have:
f2Cos^2 = fs1sin (P2, (25)
Condition of non-penetration of the roll surface ds1 cos^2 = ds2 sin (p2, (26)
When compiling the global stiffness matrix, transforming equations (23, 24) taking into account (25,
Rice. 4. Layout of equal-strength inserts in the deformation zone during rolling. H0 is the thickness of the workpiece before it enters the rolls; y, x - values of insertion coordinates;
a0, b0 and ax, bx
initial and final dimensions of the inserts, respectively
52, db1, you can also use
26), excluding /51, /5, is called when solving system (19) by the Gaussian elimination method. During the solution, the values of accumulated deformation, stresses and displacements are found, i.e. the stress-strain state in the deformation zone.
The adequacy of the model is verified on the basis of experimental studies of ring rolling given in the work. In this work, we investigated the deformation zone of a ring made of aluminum alloy AMg6, in which
Holes were drilled in layers and filled with inserts made of the same metal (Fig. 4). Rolling of rings with an outer diameter of 400 mm, an inner diameter of 340 mm and a thickness of 30 mm was carried out on a ring rolling mill model PM1200 with the diameters of the work rolls: upper drive - 550 mm and lower non-drive - 200 mm; the maximum feed speed of the pressure device was 16 mm/sec.; the rolling speed provided for by the mill design was 1.5 m/sec. Based on the results of measuring the inserts, the values were found
"h T| /) / [>
___^ S.GChS1 IG I /1^1111.1S
¿■¡i nt I a
V №|en.nch I data
5vep;rsks t;
anspsro-."and that
SgU 1, and inm b?
S:ch:"ini 2 ^ I member MZDSL.-fEBaMN!
■I l -I l i i e. 2 t.i 11 i. 7VDSH1 V ■DIM [-1
Rice. Fig. 5. Distribution of the intensity of deformation along the height of the deformation zone during rolling of a ring sample from the AMg6 alloy: e1 is the degree of accumulated deformation, y is the coordinates of the point along the y axis (with Ho /2 corresponding to ordinate 1)
deformations and stresses, which are presented in Fig. 5. The presented experimental data on rolling out a ring made of AMg6 alloy were introduced into the developed finite element model. In Fig. Figure 5 compares the simulation results and experimental data.
As can be seen from the graph, the results of the experiment and simulation are almost identical (convergence is about 15%).
1. To form a homogeneous macrostructure and the required level of mechanical properties in the annular parts of a gas turbine engine, it is necessary to control the magnitude of the accumulated degree of deformation at each stage of hot rolling of the workpiece.
2. A finite element design model has been developed.
the degree of accumulated deformation at various stages of deformation of ring blanks.
3. A comparison of modeling results and experimental dependencies confirms the adequacy of the model.
BIBLIOGRAPHY
1. Lakhtin Yu.M., Leontyeva V.P. Metallurgy. M.: Mechanical Engineering, 1980. 493 p.
3. Tselikov A.I. Theory of force calculation in rolling mills. - M.: Metallugrgizdat, 1962.
2. Finite-element plasticity and metalforming analysis / G.W. Rove., C.E.N. Sturgess, P. Hartly., Cambridge University Press, 2005. 296 p.
4 P.I. Polukhin, G.Ya Gun, A.M. Galkin Resistance to plastic deformation of metals and alloys. , M. Metallurgy, 1983, p. 353
5 Kostyshev V.A., Shitarev I.L. Rolling out rings. -Samara: SSAU, 2000. P. 206.
THE FINAL-ELEMENT MODEL CALCULATION SIZE SAVED DEFORMATION IN THE PROCESS OF HOT ROLLING RINGS
© 2009 F.V. Grechnikov1, E.V. Aryshensky1, E.D. Beglov2
It is developed, is final-element model of calculation degree the saved up deformation at various stages of deformation of ring preparation. Comparison of results of modeling and experimental dependences confirms adequacy of model.
Key words: rolling rings, macrostructure, recrystallization, the saved up deformation, method of final elements, model, a rigidity matrix, full-strength inserts.
Fedor Grechnikov, Doctor of Technics, Professor, Corresponding Member of Russian Academy of Sciences, Vice Rector for Academic Affairs. Email: [email protected]. Evgenie Aryshensky, Graduate Student. Email: [email protected].
Erkin Beglov, Candidate of Technics, Leading Engineer. Email: [email protected]
1. STATE OF THE ISSUE AND FORMULATION OF RESEARCH TASKS.
1.1 Areas of application of ring products in modern industry
1.2 Basic methods for manufacturing aircraft gas turbine engine rings.
1.3 Experimental methods for studying the deformation zone.
1.4 Analytical methods for studying the deformation zone during rolling and unrolling.
1.5 Application of the finite element method to study the deformation zone during rolling and rolling.33.
1.6 Brief characteristics of the alloys KhN68VMTYUK-VD and KhN45VMTUBR-ID and the mechanism of their recrystallization.
1.7 Review of studies of the thermal state of metal in the deformation zone during ring rolling and flat rolling.
2. DETERMINATION OF THE DEPENDENCE OF THE SHARE OF RECRYSTALLIZED VOLUME ON TEMPERATURE, DEGREE OF DEFORMATION AND TIME INTER-STRAIN PAUSE FOR KHN68VMTYUK-VD AND ALLOYS
KHN45VMTYUBR-ID.
2.1 Analysis of the formation mechanism during hot rolling of gas turbine engine rings.
2.2 Objectives and methodology of the experiment.
2.3 Equipment and instruments for research.
2.4 Study of the process of primary recrystallization in the alloys KhN68VMTYUK-VD and KhN45VMTUBR-ID after hot deformation.
3. DEVELOPMENT OF A MATHEMATICAL MODEL OF THE PROCESS OF HOT ROLLING OF RING PARTS OF GTE.
3.1 Basic assumptions and hypotheses.
3.2 Mathematical description and discretization of the solution area.
3.3. Approximation of displacement, strain and stress fields.
3.3.1 Approximation of displacements in an element.
3.4. Compilation of local global stiffness matrices. Main system of equations of the finite element method.
3.4.1 Construction of a local stiffness matrix.
3.4.2 Construction of the global stiffness matrix.
3.4.3 Accounting for boundary conditions.
3.5. Construction of a temperature field model.
3.6. General structure of the mathematical model.
4. STUDY OF THE INFLUENCE OF INTER-STRAIN PAUSES ON THE AMOUNT OF ACCUMULATED STRAIN AND TEMPERATURE WHEN ROLLING OUT OF GTE RINGS.
4.1 Description of the stages of rolling out gas turbine engine rings.
4.2 Search for optimal compression modes and the duration of the interdeformation pause during hot rolling of gas turbine engine rings.
4.3 Comparison of simulation results with experimental data.
4.4 Checking the results found using a thermal imager
4.5. Industrial research of ring rolling modes with regulation of the interdeformation pause.
5 SEARCHING FOR OPTIMUM MODES OF LOCAL COMPRESSIONS AND SPEED OF DEFORMING TOOL WHEN ROLLING OUT GTE RINGS.
5.1 Determination of permissible deformation time.
5.2 Selecting the optimal rotation speed and the magnitude of local compression.
Relevance of the topic. Gas turbine engines (GTE) are widely used in aircraft and gas pumping stations. Today, there is a high level of competition in the domestic and foreign engine industry. Therefore, enterprises involved in the production of gas turbine engines strive to ensure that their products meet the highest requirements for the most important performance characteristics. Operational reliability and other important parameters of a gas turbine engine depend mainly on the quality of its component parts.
One of the most important parts in engine building is gas turbine engine rings that serve as connecting elements. Failure of even one ring can lead to breakdown of the entire engine, i.e. an emergency situation. Therefore, the ring parts of aircraft gas turbine engines operating under conditions of high temperatures and dynamic loads are subject to high requirements for uniformity of structure and level of mechanical properties. One of the main methods for producing ring parts is hot rolling from a forged blank. A characteristic disadvantage of this process is the appearance in the annular part during the final heat treatment of areas with coarse grains, which are a consequence of the metal obtaining critical values of the degree of plastic deformation. The different-grain structure of the ring, in turn, leads to a sharp decrease in the level of mechanical properties and service life of these parts under difficult operating conditions.
The appearance of zones with coarse grains in the ring workpiece is facilitated by the fractional deformation during rolling. In fact, the rolling of a ring is a set of local deformation acts in which hardening occurs. Between these local acts, an interdeformation pause occurs in which partial recrystallization is observed and strain hardening is removed. A decrease in the degree of strain hardening, in turn, contributes to the emergence of zones with coarse grains during the final heat treatment of the ring.
The purpose of this work is to improve the technological modes of hot rolling of gas turbine engine ring parts based on the developed finite element model for calculating the accumulated deformation, taking into account the temperature and rate parameters of deformation, the duration and number of interdeformation pauses
To achieve this goal, it is necessary to solve the following tasks:
1. Establish the dependence of the change in the fraction of the recrystallized volume of the ring blank on the heating temperature, the degree of deformation and the time of the interdeformation pause for the alloys KhN68VMTYUK-VD and KhN45VMTYUBR-ID (typical materials for gas turbine engine rings).
2. Develop a finite element model to calculate the values of the degree of deformation accumulated during the rolling process, taking into account the heating temperature of the workpiece, the magnitude of local compression and the duration of each interdeformation pause.
3. Based on the developed mathematical model, study the influence of the heating temperature of the workpieces, the magnitude of local compression, the duration and number of interdeformation pauses on the degree of accumulated deformation over the entire rolling cycle.
4. Develop recommendations for the selection of temperature-speed and deformation modes of hot rolling, the number and duration of interdeformation pauses, ensuring the calculated values of accumulated deformation, homogeneity of the macrostructure and the required level of mechanical properties of ring blanks.
5. Conduct a pilot test of the adequacy of the developed technological modes for hot rolling of ring parts to the requirements for macrostructure and level of mechanical properties.
The scientific novelty of the work is as follows:
1. The process of hot rolling of gas turbine engine rings is considered as a process with fractional deformation, consisting of multiple local compressions and subsequent multiple acts of partial recrystallization in interdeformation pauses.
2. A finite element model has been constructed that makes it possible to study the hot rolling of ring blanks taking into account the heating temperature of the metal, the degree of local compression and the duration of interdeformation pauses.
3. The dependences of the change in the fraction of the recrystallized volume of the ring billet from the alloys KhN6 8VMTYUK-VD and KhN45VMTYUBR-ID (typical materials for gas turbine engine rings) on the heating temperature, the degree of deformation and the time of the interdeformation pause were established.
4. Using a ThermaCAM P65 thermal imager, the thermal field during rolling of gas turbine engine rings was studied and the optimal duration of the deformation process was established.
The reliability of the scientific research results is confirmed by the use of the most accurate and modern method for studying plastic media (the finite element method) for modeling, the use of a software product in the modern C + language to implement the model, as well as a wide range of experimental studies.
Research methods. Studies of the stress-strain state during rolling of gas turbine engine rings were carried out using a finite element model, on the basis of which a software product was created in the C + language. The experimental studies consisted of upsetting and etching samples of the alloys KhN68VMTYUK-VD and KhN45VMTUBR-ID and studying their macrostructure using an Axiovert 40 MAT device. Experimental rolling of the ring was carried out on a PM1200 rolling machine, followed by cutting samples from the ring blank and studying the mechanical properties on a TsTsMU 30 stretching machine and the macrostructure using an Axiovert 40 MAT device. The temperature field was studied using a ThermaCAM P65 thermal imager.
The author defends a finite element mathematical model that allows one to analyze the process of rolling out gas turbine engine rings, taking into account the fractional deformation. Established patterns of changes in the fraction of recrystallized volume depending on temperature, degree of deformation and time of the interdeformation pause for the alloys KhN68VMTYUK-VD, KhN45VMTUBR-ID. Distribution of local compression and rotation speed of the drive roll when rolling gas turbine engine rings, providing specified values of the degree of accumulated deformation. Experimental studies of the thermal field of a deformable ring workpiece.
Practical value of the work.
1. Based on the developed mathematical model, the problem of determining the values of the degree of deformation accumulated over the entire rolling cycle depending on specific process parameters has been solved, which makes it possible to ensure its optimal values before the final heat treatment.
2. Recommendations have been developed for the selection of optimal temperature and speed conditions for local compression of a ring workpiece, taking into account the feed rate and rotation speed of the drive roll, ensuring uniformity of the structure and high mechanical properties.
3. The results obtained in the dissertation were used at JSC Motorostroitel and JSC SNTK NES Engines named after. N.D. Kuznetsov in the development of technology for hot rolling of ring blanks from alloys KhN68VMTYUK-VD and KhN45VMTUBR-ID
Approbation of work. The main results of the work were reported and discussed at the following conferences: Royal Readings (Samara, 2007), All-Russian Scientific and Technical Conference of Students "Student Spring 2008: Mechanical Engineering Technologies" (Moscow 2008), Reshetnev Readings (Krasnoyarsk 2008). International scientific and technical conference "Metalphysics, mechanics of materials, nanostructures and deformation processes" (Samara 2009) Publications. 6 works have been published on the topic of the dissertation, including 2 articles in leading peer-reviewed journals and publications recommended by the Higher Attestation Commission.
Structure and scope of work. The dissertation consists of an introduction, four chapters, main results and conclusions, a bibliography of 133 titles, contains 138 pages of typewritten text, 58 figures, 3 tables.
MAIN RESULTS AND CONCLUSIONS
1. A mathematical finite element model of hot rolling of gas turbine engine rings has been developed, taking into account the fractional deformation, which makes it possible to determine the temperature of the workpiece, the degree of accumulated deformation and take into account the influence of the values of local compression and interdeformation pauses on these parameters.
2. The patterns of changes in the fraction of the recrystallized volume of the annular blank depending on the rolling temperature, the degree of deformation and the duration of the interdeformation pause for the alloys KhN68VMTYUK-VD and KhN45VMTUBR-ID have been established.
3. At each stage of forming, the values of the heating temperature, the degree of local compression and the duration of interdeformation pauses necessary to obtain the calculated value of the accumulated deformation in the annular workpiece before the final heat treatment have been established.
4. Comparison of data obtained by modeling and experimentally shows high convergence and confirms the adequacy of the developed finite element model.
5. In general, based on meta-mathematical modeling, scientifically grounded technological modes of hot rolling with regulated values of deformation temperature, rotation speed and feed rate of the drive roll have been developed, ensuring homogeneity of the macrostructure and increasing the strength properties of the annular parts of the gas turbine engine by 8 - 10% and plastic ones by 15 - 21%.
6. By increasing the reliability and durability of the ring parts of the gas turbine engine when operating the NK-32 engine, the total economic effect of the implementation amounted to 1,000,000 million rubles for each engine
1. Kostyshev, V.A. Methods for measuring the shape of profile ring blanks by rolling / V.A. Kostyshev, F.V. Grechnikov, - Samara: Samara Publishing House. state aerospace, univ., 2007 71 e.
2. Kostyshev, V.A. Rolling out rings / V.A. Kostyshev, I.L. Shitarev. Samara: Samar Publishing House. state aerospace, university, 2006 - 207 e.
3. Alekseev, Yu.N. Study of the state during rotational extrusion of bimetallic shells / Yu.N. Alekseev // Aircraft manufacturing. Air tech. fleet. Rep. interdepartmental thematic scientific and technical collection 1976. No. 39. pp. 57-62.
4. Barkaya, V.F. To the theory of calculation of forces and accuracy of rotational shaping processes / V.F. Barkaya // Proceedings of the Georgian Polytechnic Institute. 1975. No. 1. From 173-177.
5. Shepelev, I.N. Production of ring blanks from sheet stamped and heat-resistant alloys using a pressing 195 installation with heating of the deformation zone / I.N. Shepelev, G.N. Proskuryakov // Aviation industry. 1975. No. 3. pp. 60-63.
6. Bogoyavlensky, K. N. Production of thin-walled profiles from titanium and its alloys on a profile forming mill / K. N. Bogoyavlensky, A. K. Grigoriev // Pressure processing of metals. Proceedings of LPI. M.-L.: Mashgiz, 1963. - Issue. 222 f. - pp. 148-150.
7. Proskuryakov, G.V. Constrained bending / G.V. Proskuryakov //Aviation industry. 1966. No. 2. pp. 9-13.
8. Ershov, V.I. To the calculation of forming processes under the influence of several loads / V.I. Ershov II Proceedings of Kazan, aviation. in-ta. Aviation technology. 1980. No. 2. pp. 103-107.
9. Naydenov, M.P. Fundamentals of calculation of power parameters of tangential processing of tubular blanks using the theory of dimensions / M.P. Naydenov // Metal forming in mechanical engineering. 1974. No. 12. pp. 8-16.
10. Nazartsev, N.I., Svitov B.V. Development of technology for manufacturing seamless cylindrical thin-walled shells using the rolling method / N.I. Nazartsev, B.V. Svitov // Steels and non-ferrous metal alloys. Kuibyshev. 1974. pp. 84-92.
11. P. Ershov, V.I. Analysis of two methods of local deformation / V.I. Ershov // Proceedings of Kazan, aviation. in-ta. Aviation technology. 1981. No. 1. pp. 87-92.
12. Kolganov, I. M. Study of the process of shaping profiles by constrained bending in a tool die / I. M. Kolganov, G. V. Proskuryakov. - Togliatti, 1979. 9 p.
13. Zinoviev, V.N. Research and improvement of the process of rolling rings from titanium alloys: Abstract of Ph.D. diss. M, 1977. 16 p.
14. Kostyshev, V.A. Study of the technological process of manufacturing rolled thin-walled seamless profile rings for aircraft engines: Cand. diss. Kuibyshev, 1982. 219 p.
15. Mikhailov, K.N. The main tasks of science and industry in the development of rolling processes / K.N. Mikhailov, M.S. Sirotinsky // II Scientific and Technical Bulletin VILS: Technology of light alloys. 1973 No. 11. pp. 9-10.
16. Zuev, G.I. Hot rolling of profile ring parts / G.I. Zuev,
17. A.I. Murzov, V.A. Kostyshev, B.S. Samokhvalov. // Aluminum alloys and special materials. Proceedings of VIAM. 1975. No. 9. pp. 157-162.
18. Murzov, A.I. Rolling of titanium seamless complex-profile rings / A.I. Murzov, V.A. Kostyshev, G.I. Zuev, A.A. Chuloshnikov // Aluminum alloys and special materials. Proceedings of VIAM. 1977. No. 10. pp. 155-160.
19. Murzov, A.I. Production of seamless U-shaped rings from heat-resistant alloys using a new rolling scheme / A.I. Murzov, G.I. Zuev,
20. V.A. Kostyshev, F.I. Khasanshin, V.S. Samokhvalov // Aluminum alloys and special materials. Proceedings of VIAM. 1977. No. 10. pp. 160-165.
21. Panin, V.G. Profiling of ring blanks during hot rolling / V.G. Panin, A.N, Buratov // Information and technical bulletin: -Kuibyshev, 1988 No. 12. -P.6.
22. Panin, V.G. Production of profile ring blanks on rolling machines / V.G. Panin, A.N., Buratov // Information and technical bulletin: Kuibyshev, 1989 - No. 3. -P.2.
23. Kiselenko, I.A. Rolling out flanged ring blanks of gas turbine engines / I.A. Kiselenko, I.L. Shitarev, A.N. Chikulaev // Rolling of ring blanks of gas turbine engines // Aviation industry. 1988. - No. 7 - P. 13 - 14.
24. Zinoviev, V.N. Possibility of rolling 2000 titanium rings with high mechanical properties on the KPS mill. / V.N., Zinoviev, L.N. Ivankina // Production of titanium alloys. WILS. 1975. No. 7. S. 283288.
25. Panin, V.G. The influence of deformation conditions on the filling of calibers during rolling and methods of forming ring blanks for gas turbine engines / V.G. Panin, A.N. Butrov // Aviation industry. 1989. - No. 11 -P.20-22.
26. Panin, V.G. The influence of ring profile dimensions and the thickness of the original blank on the gauge filling rate / V.G. Panin, A.N., Buratov, G.F. // Information and technical bulletin: Kuibyshev, 1989 - No. 10. -P.4.
27. Polukhin, P.I. Production of blanks using the ring rolling method. / P.I. Polukhin // News of universities. Ferrous metallurgy 1970 No. 11. P. 16 -19.
28. Solovtsev, S.S. Shaping of ring blanks during hot rolling with a T-shaped cross-section profile / S.S. Solovtsev, M.Ya. Alypits // Forging and stamping production. 1970. No. 2. pp. 1-4.
29. Rabinovich, JI.A. Production of seamless ring blanks by machine rolling / L.A. Rabinovich // Production and technical bulletin. 1971. No. 10. pp. 6-9.
30. Papin, V.G. Kinematic relationships when rolling out rings of rectangular cross-section / V.V. Papin // In the Proceedings of the Leningrad Polytechnic Institute. 1970. No. 315. pp. 105-109
31. Bogoyavlensky, K.N. Cold rolling of ring parts / K.N. Bogoyavlensky, V.V. Lapin // Forging and stamping production. 1973. No. 2. pp. 18-22.
32. Davydov Yu.D. Designing a drawing of a forging of a rolling ring using a computer / Yu.D. Davydov // Forging and stamping production. 1969. No. 11. C, 9-11.
33. Vieregge. G. Gestaltung einer Riugschmiede under besonderer Berucksichligung des Rmgwalzverfahrens./ G. Vieregge. //Stahl imd Eisen, 1971, 91. No. 10, pp. 563-572.
34. Kazantsev, V.P. Stamping of precision blanks for rolling rings / V.P. Kazantsev, V.V. Novichev // Technology of light alloys. 1975. No. 12. pp. 80-81.
35. Formation of shrinkage when rolling shaped rings. ""Int. J.Mech. Sei." 1975, 17, No. 11-12, pp. 669-672. RZh 14B, 1976, 6B64.
36. Rozhdestvensky, Yu.L. Features of forming of ring blanks and radial ball bearings during hot closed rolling / Yu.L. Rozhdestvensky, G.P. Ostroushin // Proceedings of the VNIIP Institute. 1967 No. p. 38-40.
37. Sidorenko, B.N. Technological features of manufacturing ring parts by rolling / B.N. Sidorenko, B.F. Savchenko // Technology and organization of production. 1973. No. 3. pp. 38-41.
38. Shchevchenko L.N., Doroshevich A.G. Preparation of ring blanks from alloy D16 using the radial rolling method / L.N. Shchevchenko, A.G. Doroshevich // Production and technical bulletin. 1975. No. 6. P. 2425.
39. Pressure on the rollers and torque when rolling out rings. "Int. J. Mech. Sei" 1973, 11, 15, No. 11, p. 873-893.
40. Rolling of rings at the Woodhouse and Rixson plant. Ring rolling at Woodhouse and Rixson. "Met and Metal Form." 1973, 40, No. 8, p. 233. Ref.: RJ Metallurgy, 1974, 2D79.
41. Papin, V.G. Hot deformation of the alloy KhN65VMBU-ID on rolling machines / V.G. Papin, V.A. Kostyshev // Information and technical bulletin: Kuibyshev, 1988 - No. 11. -P.2.
42. Kostyshev V.A. Stress state in the deformation zone during rolling of aircraft engine rings, taking into account the theory of anisotropic media: / V.A. Kostyshev // Collection of SSAU. Samara, 1997. pp. 57-63.
43. Weber K.N. "Stahl und Eisen", 1959, Bd 79, Nr. 26, pp. 1912-1923.
44. Node T., lamato H. "Sumitomo Metals", 1976, a: 28, No. 1, pp. 87-93.
45. Kotelnikova L.G. Production of precision blanks of machine-building parts by rolling. / L.P. Kotelnikova, G.G. Shalinov // M.: VNIINFORMTYAZHMASH, 1968. P. 155-203.
46. Johnson W., Hawkuard J.B. "Metallurgia und Metal Forming", 1976, v. 43, No. 1, pp. 4-11. (EI.TOKP, No. 19, 1976.)
48. Moderne Ringproduktion auf Banning HV Rmgwalzmaschinen. Vortrag. Sclirmedeaurustungkongress "Forming Equipment Symposium", US -Forging Industry Association. Chicago. 1973, pp. 104-108.
49. Lapin V.V., Fomichev A.F. Study of shape changes during rolling of rectangular rings / V.V. Lapin, A.F. Fomichev. //Proceedings of the Leningrad Polytechnic Institute. 1969. No. 308. pp. 144-148.
50. Winship J.T. Cold ring-rolling warms up Amer. /J.T. Winship Mach., 1976, 20, No. I, pp. 110-113 (EI. TOKP, No. 20, 1976.)
51. Neuveau lammoir automatique a anneaux. "Metaux deform." 1979, no. 52, pp. 31-36 (EI. TOKP, No. 9, 1980.)
52. Hawkyaid J.B., Ingham P.M. An investigation into profile ring rolling. /J.B. Hawkyaid, P.M. Ingham // "Proc. 1st. Int. Conf. Rotary Metahvork. Process., London, 1979." Kempston, 1979, pp. 309, 311-320 (EI. TOKP, No. 40, 1980.)
53. Yang, H. Role of friction in cold ring rolling. / H. Yang L. G. Guo, // Journal of Materials Science & Technology,. 21 (6) (2005) pp 914-920/
54. Hot rolling of steel rings and shells / B.I. Medovar // K.: Nauk, Dumka, 1993.-240 p.
55. Guo, lg Simulation for guide roll in 3D-FE analysis of cold ring-rolling, / lg Guo, H. Yang, M. Zhan, // Mater. Sci. Forum 471-472 (2004), pp 99-110.
56. Alfozan, Adel. Design of profile ring rolling by backward simulation using upper bound element technique (UBET) / Adel. Alfozan; Jay S. Gunasekera // 2002, vol. 4, n 2, pp. 97-108 12 page(s) (article). (39 ref.)
57. Ranatunga, V., "Modeling of Profile Ring Rolling with Upper Bound Elemental Technique" Ph.D. Dissertation, Ohio University, 2002.
58. Guo, Lianggang. Research on plastic deformation behavior in cold ring rolling by FEM numerical simulation / Lianggang Guo, He Yang and Mei Zhan // 2005 Modeling Simul. Mater. Sci. Eng. 13 1029-1046.
59. Abramova, N. Yu. Fabrication and Study of Roll-Forged Rings with Controlled Structure from Imported Nickel Alloys / N. Yu. Abramova, N. M. Ryabykin, Yu. V. Protsiv // Metal Science and Heat Treatment, 2002. - Vol. 41.No. 9 -10. - p. 446-447.
60. Avadhani, G. S. Optimization of process parameters for the manufacturing of rocket casings: A study using processing maps / G. S. Avadhani // Journal of Materials Engineering and Performance, 2003. - Vol. 12. No. 6. - P 609 - 622.
61. WANG, Min. Dynamic explicit FE modeling of hot ring rolling process / Min. WANG, He Zhi-chao YANG, Liang-gang GUO, Xin-zhe OU // Trans. Nonferrous Met. Soc. China Vol.16 No. 6 (Sum. 75) Dec.2006
62. Stanistree T.F. The design of a flexible model ring rolling machine / T.F. Stanistreet, J.M. Allwood, A.M. Willoughby // Volume 177, Issues 1-3, 3 July 2006, Pages 630-633
63. Ingo Tiedemann. Material flow determination for radial flexible profile ring rolling / Ingo Tiedemann, Gerhard Hirt, Reiner Kopp, Dennis Mich, Nastaran Khanjari // Springer Berlin / Heidelberg Volume 1, Number 3 / November 2007 pp. 227-232.
64. Kang, B. Kobayashi, S. "Preform Design in Ring Rolling Processes by the Three-Dimensional Finite Element Method," / B. Kang, S. Kobayash International Journal of Machine Tools & Manufacture (v30, 1991), pp. 139151.
65. Kluge, A. "Control of Strain and Temperature Distribution in the Ring Rolling Process," / A. Kluge, Y. Lee, H. Wiegels, and R. KOPP // Journal of Materials Processing Technology (v45, 1994), p. 137.
66. Hua L. The extremum parameters in ring rolling / L. Hua; Z.Z. Zhao // Journal of Materials Processing Technology, Volume 69, Number 1, September 1997, pp. 273-276(4)
67. Panin, V.G. Development and implementation of shaping methods during hot rolling of economical flanged ring blanks for gas turbine engines: Cand. diss. Samara, 1998. 218 p.
68. Yang, D. Y. Simulation of T-section profile ring rolling by 3D rigid plastic Finite Element Method / D.Y. Yang, U Kim, JB D Hawkyard, Int. J. Mech. Sci. Vol 33, No 7, pp 541-550. 1991
69. Coupu J. Investigation of hot ring rolling using 3D finite element simulation D. Modeling of Metal Rolling Processes. / J. Coupu, J.L. Raulin., J Huez //. London, 1999
70. Ilyin, M.M. Production of solid-rolled rings and blanks / M.M. Ilyin // M.: Oborongiz, 1957. 126 p.
71. Kostyshev, V.A. Development of scientifically based methods for shaping thin-walled profile rings of aircraft engines. Doc. diss. Samara, 1998. - 307 p.
72. Hollenberg A., Bemerkunden zu den Vorgangen bein Walzen von Eisens, St. u. E., 1883, No. 2, pp. 121-122.
73. Smirnov, B.C. Theory of metal forming. / B.C. Smirnov // M: Metallurgy. 1973. 496 s.
74. Irinks W„ The Biasi Fumav and Steel Plaut, 1915. 220 p.
75. Tarnovsky, I.Ya. Deformation of metal during rolling./ I.Ya. Tarnovsky, JI.A. Pozdeev, V.B Lyashkov M: // Metallurgizdat, 1956. 287
76. Muzalevsky, O.T. Strain rate distribution in the compression zone during rolling. / O.T. Muzalevsky // Engineering methods for calculating technological processes of metal forming. M.: Metallurgizdat, 1964. P. 228-234.
77. Storozhev M.V., Theory of metal forming. / M.V. Storozhev, E.A. Popov // M.: Mashinostroenie, 1971. 424 p.
78. Tretyakov, A.V. Mechanical properties of metals and alloys during pressure treatment. / A.V. Tretyakov, V.I. Zyuzin // M.: Metallurgy, 1973. 224 p.
79. Siebel. E. "Kraft und materialflub bei der bildsamen formanderung." / E. Siebel. // 1923 Stahl Eisen 45(3 7): 1563
80. Von Karman. "Bietrag zur theorie des walzvorganges." / Karman Von // 1925 Z. angewMath. Mech5: 1563.
81. Ekelund. S. "The analysis of factors influencing rolling pressure and power consumption in the hot rolling of steels." / S. Ekelund // 1933 Steel93(8): 27.
82. Wusatowski Z. Fundamentals of rolling / Z. Wusatowski // 1969 Pergamon.
83. E. Siebel and W. Lueg. Mitteilungen aus dem Kaiser Wilhelm. Institut Fur Eisenforschung, Dusseldorf.
84. E. Orowan. "The calculation of roll pressure in hot and cold flat rolling." / Orowan E. // 1943 Proc. Institute of Mechanical Engineers 150: 140
85. Rudkins. N. "Mathematical modeling of set-up in hot strip rolling of high strength steels." / N. Rudkins, P. Evans // 1998 Journal of Material Processing Technology 80 81: 320 -324.
86. Smirnov B.S. Theory of metal forming. / B.C. Smirnov // M: Metallurgy. 1973. 496 p.
87. R. Shida. "Rolling load and torque in cold rolling." / Shida, R. Awazuhara, H. // 1973 Journal of Japan Society Technological Plasicity 14(147): 267.
88. J. G. Lenard. Study of the predictive capabilities of mathematical models of flat rolling. / J. G. Lenard // 1987 4th International Steel Rolling Conference, Deauville, France.
89. J. G. Lenard, A. Said, A. R. Ragab, M. Abo Elkhier. "The Temperature, roll force and roll torque during hot bar rolling." / J. G. Lenard, A. Said, A. R. Ragab, M. Abo Elkhier // 1997 Journal of Material Processing Technology: 147-153.
90. Alexander. J. M. On the theory of rolling. / J. M. Alexander // Proceedings Rolling Society, 535-555, London 1972.
91. Turner. M. J. "Stiffness and Deflection Analysis of Complex Structures." / M. J. Turner, R. W. Clough, H. C. Martin and L. J. Topp. // 1956 Journal of Aeronautical Science23: 805-823.
92. Zienkiewicz O. C. The Finite Element Method / O. C. Zienkiewicz // 1977 New York, McGraw-Hill.
93. Gun, G. A. Mathematical modeling of metal pressure processing processes / G. A. Gunn // M.: Metallurgy. 1983 352 pp.
94. Hartley, P. Friction in time element analyzes of metalforming processes / P. Hartley, C.E.N. Strugess, G. W. Rove / Int. J. Mech Sci Vol. 21 pp 301 311, 1979.
95. T. Sheapad D.S. Wright Structural and temperature variations during rolling of aluminum slabs / T. Sheapad D.S. // Metals Technology, 1980 No. 7.
96. Smirnov B.S. Theory of metal forming. / B.C. Smirnov // publishing house "Metallurgy" 1967. 520 p.
97. Kudryavtsev, I.P. Textures in metals and alloys / I.P. Kudryavtsev // M.: Metallurgy, 1965. 292 p.
98. Kovalev, S.I. Stresses and deformations during flat rolling / S.I. Kovalev, N.I. Koryagin, I.V. Shirko // M.: Metallurgy, 1982. 256 p.
99. J Hirschi, K-KraHausen, R. Kopp; in "Aluminum Alloys", proceedings ICAA4 Allanta/GA USA (1994) edit by T.N. Sanders, E. A. Starke, vol 1, p. 476.
100. Mori, K. "General purpose fem simulator for 3-d rolling." / Mori K. // 1990 Advanced Technology of Plasticity 4: pp 1773-1778.
101. Park J. J. "Application of three dimensional finite element analysis to shape rolling processes." / J. J. Park and S. I. Oh // 1990 Transaction ASME Journal of Engineering Ind 112: 36-46.
102. Yanagimoto, J. "Advanced computer aided simulation technique for three dimensional rolling processes." / J. Yanagimoto and M. Kiuchi // 1990 Advanced Technol. Plas 2: 639-644.
103. Kim, N. S. "Three-dimensional analysis and computer simulation of shape rolling by the finite and slab element method." / N. S. Kim, S. Kobayashi, T. Altan // 1991 International Journal of Machine and Tool Manufacture (31): 553563.
104. Shin, H. W. "A Study on the Rolling of I-Section Beams." / H. W. Shin, D. W. Kim, N. S. Kim // 1994 International Journal of Machine and Tool Manufacture 34(147-160).
105. Park, J. J. "Three-dimensional finite element analysis of block compression." / J. J. Park, S. Kobayashi // International Journal of Mechanical Sciences 26: pp 165-176.
106. Hacquin, A. "A steady state thermo-elastoviscoplastic finite element model of rolling with coupled thermo-elastic roll deformation." / A. Hacquin, P. Montmitonnet, J-P. Guillerault // 1996 Journal of Material Processing Technology 60: 109-116
107. Nemes, J. A. "Influence of strain distribution on microstructure evolution during rod-rolling." / J. A. Nemes, B. Chin and S. Yue // 1999 International Journal of Mechanical Sciences 41: pp 1111-1131.
108. Hwang, S. M. "Analytic model for the prediction of mean effective strain in rod rolling process." / S. M. Hwang, H. J. Kim, Y. Lee // 2001 Journal of Material Processing Technology, 114: 129-138.
109. Serajzadeh, S. "An investigation on strain homogeneity in hot strip rolling process." / S. Serajzadeh, K. A. Taheri, M. Nejati, J. Izadi and M. Fattahi. // 2002 Journal of Material Processing Technology 128: 88-99.
110. Li G. J. "Rigid-plastic finite element analysis of plain strain rolling." / G. J. Li and S. Kobayashi // 1982 Journal of Engineering for Industry 104: 55.
111. Mori, K. "Simulation of plane-strain rolling by the rigid-plastic finite element method." / K. Mori, K. Osakada, T. Oda // 1982 International Journal of Mechanical Sciences24: 519.
112. Liu, C. "Simulation of the cold rolling of strip using an elastic-plastic finite element technique." / C. Liu, P. Hartley, S. E. N. Sturgess and G. W. Rowe // 1985 International Journal of Mechanical Sciences 27: 829.
113. N. Kim. "Three-dimensional simulation of gap controlled plate rolling by the finite element method." / N. Kim, S. Kobayashi // 1990 International Journal of Machine and Tool Manufacturing 30: 269.
114. Hwang, S. M. "Analysis of hot-strip rolling by a penalty rigid-viscoplastic finite element method." / S. M. Hwang, M. S. Joun // 1992 International Journal of Mechanical Sciences 34: 971.
115. Khimushin F.F. Heat-resistant steels and alloys. / F.F. Khimushin // M.: Metallurgy, 1969. 752 p.
116. Korneev, N.I. Plastic deformation of high-alloy alloys / N.I. Korneev, I.G. Skugarev //. Oborongiz, 1955 245 p.
117. Korneev, N.I. Fundamentals of the physical and chemical theory of metal forming. / N.I. Korneev, I.G. Skugarev // M.: Mashingiz, 1960. 316 p.
118. Lakhtin, Yu.M. Metallurgy / Lakhtin, Yu.M. // M.: Mechanical Engineering, 1980. 493 p.
119. Aryshensky, V.Yu. Fundamentals of calculations of limiting shape changes in sheet bending processes / Aryshensky V.Yu., Aryshensky Yu.M., Uvarov V.V. // Textbook. Kuibyshev: KuAI, 1990. 44 p.
120. Morris, J.P. A furher analysis of the earning behavior of AA 3104 aluminum alloy. Aluminum 66 / J.P. Morris, Z. Li. Lexington, L. Chen, S. K. Das // Jargang 1990 11 (pp. 1069-1073)
121. Bahman, Mirzakhani. Investigation of Dynamic and Static Recrystallization Behavior During Thermomechanical Processing in API-X70 Microalloyed Steel / Bahman Mirzakhani, Hossein Arabi, Mohammad Taghi Salehi,
122. Shahin Khoddam, Seyed Hossein Seyedein and Mohammad Reza Aboutalebi // Journal of Materials Engineering and Performance
123. Siciliano F. Jr Mathematical modeling of the hot strip rolling of microalloyed Nb, multiply-alloyed Cr-Mo, and plain C-Mn steels / Siciliano F. Jr; J. J. Jonas // 2000, vol. 31, n°2, pp. 511-530 (63 ref.)
124. Dutta B. Modeling the kinetics of strain induced precipitation in Nb microalloyed steels / B. Dutta // Acta Materialia, Volume 49, Issue 5, Pages 785-794
125. Barnet, M. R., Kelly, G. L., Hodgson, P. D., Predicting the critical strain for dynamic recrystallization using the kinetics of static recrystallization. / M. R. Barnet, Kelly,. P. D. Hodgson, Scripta Materialia, 43, 4, 365-369.
126. Aryshensky V.Yu. Development of a mechanism for the formation of a given anisotropy of properties during the rolling of strips for deep drawing with thinning. Doc. diss. Samara, 202. 312 p.
127. GOST 5639-82 Steels and alloys. Methods for identifying and determining grain size.
Please note that the scientific texts presented above are posted for informational purposes only and were obtained through original dissertation text recognition (OCR). Therefore, they may contain errors associated with imperfect recognition algorithms. There are no such errors in the PDF files of dissertations and abstracts that we deliver.
Unified Tariff and Qualification Directory of Works and Professions of Workers (UTKS), 2019
Part No. 1 of Issue No. 2 of ETKS
The issue was approved by Resolution of the Ministry of Labor of the Russian Federation dated November 15, 1999 N 45
(as amended by Order of the Ministry of Health and Social Development of the Russian Federation dated November 13, 2008 N 645)
Characteristics of work. Hot rolling of ring blanks for bearings with a diameter of up to 250 mm on rolling machines in compliance with the established dimensions. Checking dimensions with a measuring tool. Machine adjustments.
Must know: device and methods for adjusting serviced rolling machines and electric heating devices; steel grades used for ball bearing rings; purpose and conditions of use of control and measuring instruments.
Characteristics of work. Hot rolling of ring blanks for bearings with a diameter of over 250 to 350 mm on rolling machines and blanks into a conical disk for car wheels on a disc rolling mill. Setting up the mill. Hot rolling of ring blanks for bearings with a diameter of over 350 mm on rolling machines together with a more highly qualified roller.
Must know: device of the disc rolling mill and kinematic diagrams of serviced rolling machines; steel grades used for rolling blanks of machine wheel disks; temperature and heating mode of workpieces; device of control and measuring instruments.
Characteristics of work. Hot rolling of blanks of bearing rings with a diameter of over 350 mm, profile rings and spherical shells of variable thickness from heat-resistant and titanium alloys of aircraft engines with a diameter of up to 1500 mm on rolling machines. Attachment of rolling machines to rings.
Must know: kinematic diagrams of various rolling machines, disc rolling mill and heating devices used for rolling rings and spherical shells; optimal heating modes for workpieces; allowances and tolerances during processing; dependence of the degree of radial compression on the thickness at various points of the workpiece; methods for setting up sheeting machines.
Characteristics of work. Hot rolling, straightening, calibration of profile rings and spherical shells of variable thickness from heat-resistant and titanium alloys of aircraft engines with a diameter of over 1500 mm on rolling machines. Rolling of thin-walled parts made of corrosion-resistant steels and molybdenum alloys.
Must know: technological process of rolling out large-sized and thin-walled parts; design of kinematic, hydraulic and heating devices and methods for their adjustment; ways to achieve the established processing accuracy; rules for calculating parabolic shells associated with performing various works.
GOST 8732-78 applies to solid rolled pipes that do not have a welded joint, produced by hot deformation on pipe rolling mills - hot-deformed seamless steel pipes. They are significantly superior to their welded alternative counterparts in strength and resistance to deformation. This allows them to be widely used in mechanical engineering, chemical and oil industries and other critical areas.
According to state standards, seamless hot-rolled pipe is manufactured in different dimensional options:
The assortment according to GOST 8732-78 regulates the outer diameters of hot-deformed rolled pipes and the thickness of its walls. Technical requirements for products are established by GOST 8731-74.
According to the ratio of the size of the outer diameter to the wall thickness (Dн/s), seamless steel pipes manufactured by hot-rolled methods are classified as follows:
Based on quality indicators, solid-rolled hot-deformed pipe products are divided into:
five groups:
A – with standardization of mechanical properties of products;
B – with standardization of the chemical composition of the steel used;
B – control of the mechanical properties of the steel used and its chemical composition;
D – with standardization of the chemical composition of the steel used and the mechanical properties of products;
D – without standardization of mechanical properties and chemical composition, but with hydraulic tests.
and six classes:
The process of manufacturing pipes using the hot rolling method consists of three technological stages:
All technological processes The production of rolled pipes begins from the blank table. Here, workpieces of the required length are obtained from round solid rods, breaking them into hydraulic presses using pre-made cuts or cutting with shear presses without preheating.
After assembling a package of blanks, they are sent to a loading machine with a double-row loading. Heating temperature – 1150-1270℃, depending on the steel grade. After heating, the workpiece is sent along roller tables and racks to a centering machine, on which a recess is made at the end along its axis. After this, the workpiece is fed into the chute of the piercing mill.
Stitching mills come in disc, barrel and mushroom shapes. For piercing the workpiece, stands with barrel-shaped rolls rotating in one direction are most often used. The roll axes are located in vertical planes parallel to the axis of symmetry of the mill. Moreover, the roller axis makes an angle ß (feed angle) with the piercing axis from 8 to 15 degrees, depending on the size of the sleeve.
The hole in the sleeve is formed by a mandrel, which is fixed on a long fixed rod. Their axes coincide with the axis of the firmware. The heated workpiece moves towards the rolls towards a mandrel installed in the zone of maximum roll diameters - pinch. Upon contact with the rollers, the workpiece begins to move in opposite direction, and due to the feed angle it receives translational motion, which ensures a helical trajectory of each point of the deformed metal. This results in a thick-walled sleeve.
The outer diameter of the sleeve is approximately equal to the diameter of the workpiece, but due to the formation of a hole, its length increases by 2.5-4 times compared to the original length of the workpiece.
The sleeve obtained on a piercing mill is rolled into a pipe of the required diameter and wall thickness different ways. The method of rolling the sleeve into a pipe characterizes the type of pipe rolling plant. In the conditions of PNTZ, this is rolling on automatic, continuous and three-roll rolling mills.
Units with an automatic mill received the most wide application. A wide range of rolled pipes with a diameter from 57 to 426 mm and a wall thickness from 4 to 40 mm, as well as easy adjustment to pipes of other sizes, provide greater maneuverability in operation on such a unit. These advantages are combined with fairly high performance.
Structurally, the automatic mill is a two-roll non-reversible stand, the rolls of which have grooves that form a round pass. Before inserting the liner into the rolls, a stationary short round mandrel on a long rod is installed in the gauge, so that the gap between the mandrel and the gauge determines the diameter of the pipe and the thickness of its wall. The metal is deformed between the rolls and the mandrel. In this case, along with the thinning of the wall, there is a decrease in the outer diameter of the pipe.
Since rolling in one pass does not ensure uniform deformation of the wall along its perimeter, it is necessary to give two, and sometimes three passes, each time with edging, i.e. with the pipe rotated 90 degrees around its axis before placing it into rolls.
After each pass, the rolled sleeve is transferred to the front side of the stand using a pair of friction return rollers mounted on the output side of the mill. They rotate in the direction opposite to the rotation of the rolls. After each rolling, the mandrel is removed manually or using mechanisms and installed again before the next task of the liner.
The sleeve from the piercing mill falls into the chute and is pushed into the rolls by a pusher. After the first pass, the workpiece is returned, turned around its axis by 90 degrees and again fed into the rolls by a pusher. After each pass the mandrel is changed.
On three-roll rolling mills it is possible to roll pipes with a diameter of 34 to 200 mm and a wall thickness of 8 to 40 mm. The main advantage of this rolling method is the possibility of obtaining thick-walled pipes with minimal variation in thickness compared to methods of rolling pipes in round gauges.
The sleeve is deformed into a pipe using three rollers and a movable long mandrel. The rolls are equidistant from each other and from the rolling axis. The roll axes are not parallel to each other and to the rolling axis. The angle of inclination of the roll axis to the rolling axis in the horizontal plane is called the rolling angle φ, usually equal to 7 degrees. And the angle of inclination of the vertical plane is called the feed angle ß and varies in the range of 4-10 degrees, depending on the size of the rolled pipes. The rolls rotate in one direction and, due to the misalignment of their axes relative to the rolling axes, create conditions for the screw movement of the sleeve together with the mandrel.
Once on the gripping cone of the rolls, the sleeve blank with the mandrel inside is compressed along the diameter and along the wall. Deformation along the wall is carried out mainly by the ridges of the rollers. On the rolling and calibrating cones, the wall thickness is leveled, ovalization is reduced and there is a slight increase in the internal diameter of the pipe blank. This creates a small gap between the walls of the future pipe and the mandrel, which makes it easier to remove the latter from the pipe upon completion of rolling.
As calibration equipment for thick-walled pipes, a three-roll mill is used, similar in design to a rolling mill, but less powerful, since the deformation along the diameter is small and the wall thickness remains unchanged.
For pipes of smaller diameter and with smaller wall thickness, a continuous sizing mill consisting of five stands is used.
The productivity of the unit with a three-roll rolling mill is up to 180 thousand tons of pipes per year. The advantages of these mills include the ability to produce pipes high precision, quick adjustment from size to size, good quality inner surface products.
The process of rolling out a sleeve in a continuous mill takes place in a number of successively located two-roll stands. Rolling is carried out on a long movable cylindrical mandrel in stands with rolls having round gauges.
Just like on an automatic mill, cross section pipe is determined by the annular gap between the roll grooves and the mandrel. The difference is that the long mandrel moves along with the rolled pipe.
As it passes through the cages, the number of which can reach nine, the liner is reduced: it decreases in outer diameter and is compressed along the wall. Since deformation in round gauges occurs unevenly, the pipe after the stand has an oval shape, it must be set with the larger axis of the oval along the height of the gauge, i.e. having previously rotated 90 degrees around the axis. To do this, change the direction of deformation of the rolls. To do this, each subsequent cage is rotated relative to the previous one at a right angle, and the cages themselves are located at an angle of 45 degrees to the horizon. This makes it possible to increase the compression in the cages and increase the compression of the pipes.
The continuous mill is designed for a high elongation factor - up to 6, so the pipe length can reach 150 meters. The continuous mill produces pipes with a diameter of 28 to 108 mm, a wall thickness of 3 to 8 mm and a length of more than 30 meters. High rolling speed (up to 5.5 m/sec) ensures high productivity (up to 600 thousand tons of pipes per year).
The final technological operation for all pipe rolling methods is the operation of cooling the products on cooling tables. To eliminate longitudinal curvature, cooled pipes are straightened on straightening mills. Special calibrated mill rolls carry out helical movement of the pipe, thereby eliminating existing axial distortions. Pipe ends are trimmed on lathes. If necessary, chamfers are removed.
In conclusion finished goods subject to quality control. After inspection, suitable pipes are packaged using a knitting machine and then sent to the finished product warehouse.
Hot-rolled solid steel pipes are widely used in the construction of pipelines of all diameters; they are used for the production of metal structure parts, machine and mechanism elements, columns, trusses and beams, foundation piles, lighting poles, in housing and communal services and road construction.
From technical characteristics hot-rolled pipe according to GOST, the scope of its application also follows. These are highly critical pipelines that require extreme strength, virtually eliminating the possibility of leaks:
In the catalog warehouse complex "ChTPZ" presents a wide range of hot-deformed seamless steel pipes in accordance with GOST 8732-78 for the needs of the oil and gas industry, chemical industry, construction, municipal and agriculture. You can place an order on the website or by phone . Compliance with the requirements of the state standard guarantees high technical and operational characteristics and a long service life of the pipe products sold. All products come with quality certificates.
