M50 steel bearing ring and intelligent preparation method thereof

Abstract

The invention relates to an M50 steel bearing ring and an intelligent preparation method thereof.The intelligent preparation method comprises the following steps that performance testing is conducted on an M50 steel sample, and a high-temperature flow stress curve and thermophysical parameters are obtained; constructing a thermal deformation physical property metallurgy model based on the high-temperature flow stress curve; based on the thermal deformation physical property metallurgy model, combining with the thermal physical property parameters, coupling an automatic calculation model, and establishing macroscopic and mesoscopic calculation models; based on macroscopic and mesoscopic calculation models, the rolling technology of bars of different specifications and sizes is developed, and the M50 steel bars meeting the set requirements are prepared; an M50 steel bar meeting the set requirement is utilized, a simulation calculation algorithm is combined, a bearing ring shape follow-up ring rolling process is developed, and the M50 steel bearing ring meeting the set requirement is prepared. According to the invention, the integrated thermal deformation process development of the bar and the bearing ring is realized by mainly utilizing a simulation calculation method, so that the M50 steel bearing ring with excellent structure and performance is prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing preparation, and particularly to an M50 steel bearing ring and an intelligent preparation method thereof. Background Art

[0002] For the main aviation bearing steel grades, M50 aviation bearing steel is widely used due to its good high-temperature stability and wear resistance. In order to meet the requirements of high-speed, high-temperature, large-load harsh working conditions and high fatigue life service performance, it is prepared into bars by using vacuum induction + vacuum consumable melting method and traditional forging + hot rolling deformation method. Subsequently, shape and property control (i.e., controlling the morphology and properties of the ring) of the bearing ring is also required to make the bearing ring have excellent properties.

[0003] Among them, in the process of manufacturing the bearing ring, the control of carbide streamline and fine grain control are crucial for the long-life design of M50 steel bearings. However, the control of carbide streamline and fine grain structure is not only closely related to the ring rolling process, but also related to the carbide streamline and fine grain control level of the rolled bars used for the ring. In actual ring production, there is currently no integrated control method for carbides and fine grain structure in M50 steel bars and rings, and there is a lack of physical property parameters in a wide temperature range and an accurate hot deformation behavior model involved in the hot deformation process of M50 steel. It is impossible to couple advanced cross-scale simulation and calculation technologies to complete the development of rolling and ring hot deformation processes.

[0004] Therefore, in order to prepare more controllable carbide streamline and fine grain structure, it is urgent to establish a physical metallurgy model for the hot deformation of M50 steel materials. By coupling the cellular automaton calculation model, macroscopic and mesoscopic coupling can be achieved to complete the development of the best bar rolling process and ring rolling process.

[0005] Based on the current problems of low life and low stability of aviation bearings, through the development of advanced preparation methods, controlling the morphology and properties of M50 steel bearing rings will be an effective method to improve the internal quality of bearings. Summary of the Invention

[0006] In view of this, the present invention provides an M50 steel bearing ring and an intelligent preparation method thereof. The main purpose is to use simulation calculation methods to realize the integrated hot deformation process development of bars and bearing rings, so that the M50 steel bearing ring has excellent microstructure and properties.

[0007] To achieve the above object, the present invention mainly provides the following technical solutions:

[0008] On the one hand, an embodiment of the present invention provides an intelligent preparation method for an M50 steel bearing ring, which includes the following steps:

[0009] Obtain the measured data of M50 steel: Conduct performance tests on M50 steel specimens to obtain the measured data of M50 steel; among them, the measured data of M50 steel includes the high-temperature flow stress curve and thermal physical properties parameters;

[0010] Construct a thermal deformation physical metallurgy model: Based on the high-temperature flow stress curve, construct a thermal deformation physical metallurgy model; among them, the thermal deformation physical metallurgy model includes a thermal deformation constitutive equation, a kinetic model of dynamic recrystallization, a grain growth model, and a dislocation density model;

[0011] Establish macroscopic and mesoscopic calculation models: Based on the thermal deformation physical metallurgy model, combined with the thermal physical properties parameters, and coupled with an automatic calculation model, establish macroscopic and mesoscopic calculation models; among them, the macroscopic and mesoscopic calculation models include: simulation calculations of the macroscopic temperature field, stress-temperature field, and microscopic structure of M50 steel under thermal deformation conditions, and the change law of carbide streamline;

[0012] Develop the large deformation rolling process of M50 steel: Based on the macroscopic and mesoscopic calculation models, develop the rolling processes of bars with different specifications and sizes, and prepare M50 steel bars that meet the set requirements;

[0013] Develop the profile rolling process of bearing rings: Utilize the M50 steel bars that meet the set requirements, combined with the simulation calculation algorithm, develop the profile rolling process of bearing rings, and prepare M50 steel bearing rings that meet the set requirements.

[0014] Preferably, in the step of obtaining the measured data of M50 steel: the M50 steel specimen is an M50 steel consumable ingot specimen; and / or the high-temperature flow stress curve includes: the stress-strain curve under the conditions of a temperature range of 900 - 1170 °C and a strain rate range of 0.01 s -1 -10 s -1 conditions; and / or the thermal physical properties parameters include: the high-temperature diffusion temperature and the specific heat capacity curve, thermal conductivity curve, thermal expansion curve, Young's modulus curve, and Poisson's ratio curve below 1170 °C; preferably, the high-temperature diffusion temperature ≥ 1600 °C.

[0015] Preferably, in the step of establishing the macroscopic and mesoscopic calculation models: couple the macroscopic thermal deformation with the mesoscopic cellular automaton calculation method, and import the thermal deformation constitutive equation of M50 steel, the kinetic model of dynamic recrystallization, the grain growth model, and the dislocation density model to realize the simulation calculation of refined microstructure control during the bar rolling process. Preferably, based on the thermal deformation constitutive equation, calculate the thermal deformation of M50 steel through secondary development in the software, and further calculate the microstructural changes of M50 steel during the thermal deformation process through the kinetic model of dynamic recrystallization, the grain growth model, and the dislocation density model; More preferably, the software is selected from DEFORM or ABAQUS software. The "secondary development" here refers to: loading the physical model of the data obtained from experiments into the software calculation model to calculate the desired results. Preferably, for the macroscopic calculation model, establish the macroscopic finite element temperature field and stress field calculation models of M50 steel during the thermal deformation process respectively; for the mesoscopic calculation model, establish the microstructural evolution calculation model, complete the recrystallization calculation and the grain size distribution; Preferably, through cross-scale simulation calculation, complete the simulation of the streamline arrangement of carbide.

[0016] Preferably, in the step of developing the large deformation rolling process of M50 steel: if the prepared M50 steel bar does not meet the set requirements, use the performance data of the bar as a correction parameter to correct the thermal deformation physical metallurgy model, and then correct the macroscopic and mesoscopic calculation models to realize the correction of the developed bar rolling process until the prepared M50 steel bar meets the set requirements.

[0017] Preferably, in the step of developing the large deformation rolling process of M50 steel: the M50 steel bar that meets the set requirements refers to: the streamline control level with a grain size above grade 7.5 and a carbide rating ≤ 3.

[0018] Preferably, in the step of developing the large deformation rolling process of M50 steel: before rolling, the M50 steel billet needs to be processed as follows: first, perform a high-temperature diffusion treatment on the M50 steel billet at ≥ 1160 °C, and then forge and open the billet of M50 steel after the high-temperature diffusion treatment into a square billet; Preferably, during the forging and opening process: the forging ratio ≥ 5, the upsetting reduction ≥ 50%, and the deformation temperature is controlled at ≥ 950 °C; Preferably, the M50 steel billet is an M50 steel consumable ingot billet; More preferably, the cross-section of the M50 steel consumable ingot billet is circular; the square billet needs to be tested by flaw detection, with no defects above φ1.2 mm and a grain size ≥ 7.

[0019] Preferably, in the step of developing the large deformation rolling process of M50 steel, through simulation calculation and correction, the developed bar rolling process is as follows: the initial rolling temperature of the square billet is controlled at 1130 - 1150 °C, the final rolling temperature is controlled at ≥950 °C, the number of times the single-pass deformation of the billet during the initial rolling exceeds 20% is ≥1 time, and the total deformation during the rolling process is ≥50%, so that the grain size of the M50 steel bar meets ≥7.5 grades and the carbide rating is ≤3 grades.

[0020] Preferably, the development of the bearing ring profile rolling process includes the following steps:

[0021] Step 1) Based on the requirements of controlling the flow line of the ring, upset the M50 steel bar into a disc-shaped structure; preferably, the upset ratio is 1.6 - 2; it should be noted here that according to the control of the central flow line during the upsetting deformation process, two die constraints are adopted during the upsetting process, and the specific upsetting size is determined according to the simulation analysis for die constraint.

[0022] Step 2) Remove the central area of the disc-shaped structure to ensure that the included angle between the tangents on both sides of the curved flow line in the disc-shaped structure is ≥100 degrees (see the included angle between the upper and lower parts of the curved flow line in the right figure of Figure 6 ), so as to ensure that there is no large-scale bending of the remaining flow line;

[0023] Step 3) Profile roll the disc-shaped structure with the central area removed according to the shape of the raceway. Among them, the initial profile rolling temperature is controlled at 1100 - 1130 °C, the final profile rolling temperature is controlled at ≥950 °C, and the cross-sectional deformation is ≥40%.

[0024] Preferably, the M50 steel bearing ring meeting the set requirements refers to: the M50 steel bearing ring with near-surface carbides arranged along the flow line and a grain size ≥9 grades; among them, the near-surface carbides refer to the carbides within 500 μm from the surface of the bearing ring;

[0025] On the other hand, the embodiment of the present invention provides an M50 steel bearing ring, characterized in that the M50 steel bearing ring is prepared by the preparation method of the M50 steel bearing ring described in any one of the above; among them, the near-surface carbides of the M50 steel bearing ring are arranged along the flow line and the grain size ≥9 grades; among them, the near-surface carbides refer to the carbides within 500 μm from the surface of the bearing ring.

[0026] On yet another aspect, the embodiment of the present invention provides a bearing, characterized in that the bearing includes a bearing inner ring and a bearing outer ring; among them,

[0027] The bearing inner ring is prepared by the preparation method of the M50 steel bearing ring described in any one of the above; and / or

[0028] The outer ring of the bearing is prepared by using the preparation method of the M50 steel bearing ring described in any one of the above.

[0029] Preferably, the service life of the bearing is ≥2000h.

[0030] Compared with the prior art, a M50 steel bearing ring and its intelligent preparation method of the present invention at least have the following beneficial effects:

[0031] A preparation method of a M50 steel bearing ring provided by an embodiment of the present invention mainly includes the following steps: performing performance tests on M50 steel specimens to obtain high-temperature flow stress curves and thermal physical property parameters; constructing a thermal deformation physical metallurgy model based on the high-temperature flow stress curves; coupling an automatic calculation model based on the thermal deformation physical metallurgy model and combining with the thermal physical property parameters to establish macroscopic and mesoscopic calculation models; developing rolling processes for bars of different specifications and sizes based on the macroscopic and mesoscopic calculation models to prepare M50 steel bars that meet the set requirements; using the M50 steel bars that meet the set requirements and combining with a simulation algorithm to develop a profile rolling process for bearing rings to prepare M50 steel bearing rings that meet the set requirements. It should be noted for the above solution: The present invention uses the measured thermal physical property parameters and thermal deformation stress-strain data to construct the stress-strain constitutive relationship and recrystallization model of M50 steel materials, realizing stress-strain analysis during the rolling process and cross-scale carbide streamline control; using the recrystallization model and combining with stress-strain analysis during the rolling process to complete carbide streamline and fine grain structure control of bars; on the basis of the bar streamline, combining with the change of the bar streamline during the forging process of the ring, developing a streamline control processing method for bearing rings to realize groove streamline and fine grain control of the ring; through the coordinated streamline and tissue control of M50 steel bars and bearing rings, a long-life M50 steel bearing is obtained. The solution of the present invention enables the prepared M50 steel bearing ring to have better tissue and excellent material properties, meeting the service performance requirements of long-life bearings under harsh working conditions of high speed, high temperature, and large load.

[0032] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it in accordance with the content of the description, the following takes the preferred embodiment of the present invention and combines with the drawings to describe in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic flow chart of an intelligent preparation method of a M50 steel bearing ring provided by an embodiment of the present invention;

[0034] Figure 2 is a control effect diagram of the stress field, strain field, and temperature field during the rolling process of a M50 steel blank provided by an embodiment of the present invention;

[0035] Figure 3 It is an effect diagram of cross-scale carbide streamline control during the rolling process of an M50 steel billet provided by an embodiment of the present invention;

[0036] Figure 4 It is a microstructure diagram of an M50 steel bar provided by an embodiment of the present invention;

[0037] Figure 5 It is a microstructure diagram of an M50 steel ring provided by an embodiment of the present invention;

[0038] Figure 6 It is an integrated streamline control diagram of an M50 steel bar and a ring provided by an embodiment of the present invention;

[0039] Figure 7 It is an effect diagram of streamline control of an M50 steel ring provided by an embodiment of the present invention;

[0040] Figure 8 It is an arrangement diagram of carbide streamlines of an M50 steel ring provided by an embodiment of the present invention.

[0041] Figure 9 It is a grain diagram of the original M50 steel rolled bar after metallographic corrosion provided by Comparative Example 1;

[0042] Figure 10 It is an un-streamline-controlled diagram of the original M50 steel ring provided by Comparative Example 1. Detailed implementation manners

[0043] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following combines the drawings and preferred embodiments to detail the specific implementation manners, structures, features, and their effects of the application according to the present invention. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0044] An intelligent preparation method for an M50 steel bearing ring provided by the present invention, in order to better control the ring streamline and grain refinement, innovatively establishes a physical metallurgy model of the hot deformation behavior of M50 steel, and couples the macroscopic finite element and mesoscopic scale microstructure evolution models, comprehensively considering the bar streamline, fine grain microstructure control, and the streamline change during the process of preparing the ring from the bar, to achieve the optimal control of the carbide streamline and microstructure of the bearing ring, so that the M50 steel bearing ring has better microstructure and excellent material properties, meeting the service performance requirements of long-life bearings under harsh working conditions of high speed, high temperature, and large load. Among them, the main solutions of the present invention are as follows:

[0045] An embodiment of the present invention provides an intelligent preparation method for an M50 steel bearing ring, as Figure 1As described above, it includes the following steps:

[0046] Obtain the measured data of M50 steel: Perform performance tests on M50 steel specimens to obtain the measured data of M50 steel; among them, the measured data of M50 steel includes the high-temperature flow stress curve and thermal physical properties parameters.

[0047] Among them, in this step: According to the experimental characteristics of the M50 steel specimen (that is, the hot deformation characteristics of M50 steel, specifically, hot working above 1170°C will generate cracks), determine that the high-temperature diffusion range ≥ 1600°C.

[0048] In this step, complete the stress-strain curve of this material within the temperature range of 900 - 1170°C and the strain rate range of 0.01s -1 -10s -1 (using a Gleeble 3800 thermal simulation testing machine, and designing the temperature range and strain rate of the specimen to be tested, complete the stress-strain curve and the metallographic structure of the deformed specimen).

[0049] In this step, complete the parameter curves of specific heat capacity, thermal conductivity, thermal expansion, Young's modulus, Poisson's ratio, etc. of M50 steel below 1170°C.

[0050] In addition, the M50 steel specimen is a self-consumed ingot specimen of M50 steel.

[0051] Construct a thermal deformation physical metallurgy model: Based on the high-temperature flow stress curve, construct a thermal deformation physical metallurgy model; among them, the thermal deformation physical metallurgy model includes a thermal deformation constitutive equation, a kinetic model of dynamic recrystallization, a grain growth model, and a dislocation density model.

[0052] Among them, the thermal deformation constitutive equation of M50 steel is as follows:

[0053]

[0054] Write the thermal deformation constitutive equation of M50 steel as a function of the Zener-Hollomon parameter, that is:

[0055]

[0056] Strain rate; R: Gas constant, generally taken as 8,314 J / (mol·K); T: Deformation temperature; σ: Peak stress; Z: (Zener-Hollomon) parameter, related to the strain rate.

[0057] Among them, the critical strain for dynamic recrystallization of M50 steel:

[0058] ε c = 0.328ε p= 0.002788×Z 0.1276 ;

[0059] where ε c : critical strain for dynamic recrystallization; ε p : peak strain; Z: (Zener - Hollomon) parameter, related to strain rate.

[0060] where the volume fraction of dynamic recrystallization of M50 steel under different deformation conditions is:

[0061]

[0062] X DRX : volume fraction of dynamic recrystallization; ε: strain; ε c : critical strain for dynamic recrystallization;

[0063] ε p : peak strain.

[0064] where the dynamic recrystallized grain size model of M50 steel:

[0065] D DRX = 2.6016×10 2 Z -0.14527 ;

[0066] D DRX : dynamic recrystallized grain size; Z: (Zener - Hollomon) parameter, related to strain rate.

[0067] Dislocation density model:

[0068]

[0069]

[0070] h: hardening coefficient; r: radius of the action range of dislocation stress field; strain rate; strain rate trimming coefficient, generally taken as 1; R: gas constant, generally taken as 8,314 J / (mol·K); T: deformation temperature.

[0071] It should be noted here that: based on the stress - strain curve and deformed metallographic structure, and then according to the metallurgical model, the key parameters are obtained by solving equations to obtain the physical metallurgical model of M50 steel.

[0072] Establish macroscopic and mesoscopic calculation models: Based on the thermal deformation physical metallurgy model, combined with the thermal physical parameters, and coupled with the automatic calculation model, macroscopic and mesoscopic calculation models are established; among them, the macroscopic and mesoscopic calculation models include: simulation calculations of the macroscopic temperature field, stress temperature field and microstructure of M50 steel under hot deformation conditions, and the change law of carbide streamline (herein, the "carbide streamline" refers to that the carbide is consistent with the hot deformation streamline and is arranged in a regular linear pattern).

[0073] It should be noted here that: (1) Calculations are carried out based on the deform cellular automaton model; (2) During the bar rolling process, the simulation calculation of refined microstructure control will use the above-mentioned thermal deformation physical metallurgy model (including the thermal deformation constitutive equation, the kinetic model of dynamic recrystallization, the grain growth model and the dislocation density model) and calculate in the DEFORM software; using the constitutive equation, the hot deformation of the material can be calculated in the DEFORM software; the kinetic model of dynamic recrystallization, the grain growth model and the dislocation density model, etc. can calculate the change of the material microstructure during the hot deformation process of the material.

[0074] In this step: In the macroscopic finite element model part, calculation models of the macroscopic finite element temperature field and stress field during the hot deformation process of the billet are established respectively (see Figure 2 ); In the mesoscopic scale tissue evolution model part, the cellular automaton method is mainly introduced to establish a calculation model of microscopic tissue evolution, complete the recrystallization calculation and the grain size distribution. In addition, through cross-scale simulation calculations, the simulation of carbide streamline arrangement is completed (see Figure 3 ).

[0075] Here, the term "cross-scale simulation calculation" refers to: when calculating, the grid size is above mm macroscopically, and above μm for carbide and grain size. Therefore, 1mm = 1000μm, which is called cross-scale academically.

[0076] Develop the large deformation rolling process of M50 steel: Based on the macroscopic and mesoscopic calculation models, develop the rolling processes of bars with different specifications and sizes, and prepare M50 steel bars that meet the set requirements.

[0077] Among them, in this step:

[0078] 1) Preparation of the billet before rolling: The self-consumed ingot billet (self-consumed round billet) of M50 steel needs to be subjected to high-temperature diffusion at ≥1160°C; then it is forged and bloomed into the required square billet with a cross-section of 180mm×180mm - 90mm×90mm; after flaw detection, the square billet has no defects above φ1.2mm, and the grain size meets ≥7 levels.

[0079] 2) Through the simulation calculation of the hot deformation process of the bar, the following control of the bar rolling process is achieved: the initial temperature of the square billet after forging during rolling is controlled within the range of 1130 - 1150 °C, the final rolling temperature is controlled at ≥950 °C, the number of times the billet single-pass deformation amount exceeds 20% during the initial rolling process is ≥1 time, the total deformation amount during the rolling process is ≥50%, the grain size of the final rolled material meets ≥7.5 grades, and the carbide rating is ≤3 grades.

[0080] In addition, it should be noted that: if the prepared M50 steel bar does not meet the set requirements, the performance data of the bar will be used as a correction parameter to correct the thermal deformation physical metallurgy model, and then correct the macroscopic and mesoscopic calculation models to achieve the correction of the developed bar rolling process until the prepared M50 steel bar meets the set requirements.

[0081] Develop the contour rolling process of the bearing ring (integrated organization and streamline control of the bar and the ring): Using the M50 steel bar that meets the set requirements and combining the simulation calculation method (finite element and cellular automaton calculation method), develop the contour rolling process of the bearing ring to prepare the M50 steel bearing ring that meets the set requirements.

[0082] In this step: Through the simulation calculation of the hot deformation process of the ring (ring rolling deformation), the control of the ring rolling process is achieved: Based on the streamline control of the ring, select the appropriate specification rolling bar by reverse deduction; use two die size constraints during upsetting (die forging the bar in 2 stages) to achieve an upsetting ratio (original bar height / height after upsetting) of 1.6 - 2; then, remove the central area of the upset cake sample to ensure good streamline control of the remaining metal part of the cake sample; finally, perform contour high-speed rolling according to the shape of the raceway, the initial rolling temperature is controlled at 1100 - 1130 °C, the final rolling temperature is controlled at ≥950 °C, the cross-sectional deformation amount is ≥40%, and the near-surface carbide contour streamline control of the final bearing ring is achieved (wherein, the near-surface carbide refers to the carbide within 500 μm from the surface of the bearing ring), and the grain size of the ring is ≥9 grades.

[0083] The following is further illustrated by specific experimental examples as follows:

[0084] Example 1

[0085] In this example, an M50 steel bearing ring with a size specification of φ140×10 mm is prepared, as Figure 1 shown, and mainly includes the following steps:

[0086] Obtain the measured data of M50 steel: Perform performance tests on the M50 steel specimen to obtain the measured data of M50 steel; among them, the measured data of M50 steel includes the high-temperature flow stress curve and thermal physical parameters. Among them, in the temperature range of 900 - 1170 °C and the strain rate range of 0.01 s -1 -10 s-1 The stress-strain curve under certain conditions; the thermophysical properties parameters include: the high-temperature diffusion temperature and the specific heat capacity curve, thermal conductivity curve, thermal expansion curve, Young's modulus curve, and Poisson's ratio curve below 1170°C; among them, the high-temperature diffusion temperature ≥ 1600°C.

[0087] Construct a thermal deformation physical metallurgy model: construct a thermal deformation physical metallurgy model based on the high-temperature flow stress curve; among them, the thermal deformation physical metallurgy model includes a thermal deformation constitutive equation, a kinetic model of dynamic recrystallization, a grain growth model, and a dislocation density model.

[0088] Among them, the thermal deformation constitutive equation of M50 steel is as follows:

[0089]

[0090] Write the thermal deformation constitutive equation of M50 steel as a function of the Zener-Hollomon parameter, that is:

[0091]

[0092] Strain rate; R: Gas constant, generally taken as 8,314 J / (mol·K); T: Deformation temperature; σ: Peak stress; Z: (Zener-Hollomon) parameter, related to the strain rate.

[0093] Among them, the critical strain for dynamic recrystallization of M50 steel:

[0094] ε c = 0.328ε p = 0.002788×Z 0.1276 ;

[0095] Among them, ε c : Critical strain for dynamic recrystallization; ε p : Peak strain; Z: (Zener-Hollomon) parameter, related to the strain rate.

[0096] Among them, the volume fraction of dynamic recrystallization of M50 steel under different deformation conditions is:

[0097]

[0098] X DRX : Volume fraction of dynamic recrystallization; ε: Strain; ε c : Critical strain for dynamic recrystallization;

[0099] ε p : Peak strain.

[0100] Among them, the dynamic recrystallization grain size model of M50 steel:

[0101] D DRX = 2.6016×10 2 Z -0.14527 ;

[0102] D DRX : Dynamic recrystallization grain size; Z: (Zener-Hollomon) parameter, related to the strain rate.

[0103] Dislocation density model:

[0104]

[0105] h: Hardening coefficient; r: Radius of the action range of the dislocation stress field; Strain rate; Strain rate trimming coefficient, generally taken as 1; R: Gas constant, generally taken as 8,314 J / (mol·K); T: Deformation temperature.

[0106] Establish macroscopic and mesoscopic calculation models: Based on the above thermal deformation physical metallurgy model, combined with the above thermal physical parameters, and coupled with an automatic calculation model, macroscopic and mesoscopic calculation models are established; among them, the macroscopic and mesoscopic calculation models include: simulation calculations of the macroscopic temperature field, stress temperature field and microstructure of M50 steel under hot deformation conditions, and the change law of the carbide streamline.

[0107] In this step: In the macroscopic finite element model part, calculation models of the macroscopic finite element temperature field and stress field during the hot deformation process of the blank are established respectively (see Figure 2 ); In the mesoscopic scale tissue evolution model part, the cellular automaton method is mainly introduced to establish a calculation model of the microscopic tissue evolution, complete the recrystallization calculation and the grain size distribution. In addition, through cross-scale simulation calculations, the simulation of the carbide streamline arrangement is completed (see Figure 3 ).

[0108] Developing the large deformation rolling process for M50 steel: 1) High-temperature diffusion treatment: The consumable ingot is heated to 1160°C for high-temperature diffusion to achieve no obvious microsegregation between dendrites. 2) The M50 steel billet after high-temperature diffusion treatment is forged and bloomed into a square billet with a forging ratio ≥5 and a upsetting reduction ≥50%. The deformation temperature is controlled at ≥950°C. After deformation, a 150mm×150mm×L forged billet (square billet) is prepared with a grain size of grade 7. The forged billet is detected to have no defects larger than φ1.2mm. 3) Rolling: The 150mm×150mm×L forged billet (square billet) is heated to 1140°C, and the final rolling temperature is controlled at ≥950°C. The maximum reduction per pass is controlled at 30%, and the total cross-sectional deformation (total deformation during rolling) is 83%. After multiple deformations, a φ70mm bar is prepared. Coupling the M50 thermal physical property parameter data and the physical metallurgy model of thermal deformation behavior with the macroscopic finite element and mesoscopic models, the simulation results show that the grain size is grade 8. See Figure 4 as shown. The actual test result is grade 7.5, the carbide is grade 3, and there are no defects larger than φ0.8mm.

[0109] Developing the profile rolling process for bearing rings (integrated structure and streamline control of bars and rings): According to the bearing size, the required bar size and height are determined by the reverse deduction method, and then the bar is die-forged in two stages through forward simulation to meet the profile rolling height requirement. At this time, it is the rough blank of the ring. Then, according to the streamline requirement, the center of the rough blank of the ring is removed to ensure the integrity of the streamline of the remaining part of the bearing outer ring with a slight change. Then, it is profile rolled according to the shape of the raceway. See Figure 6 as shown. In this case, a φ70mm bar is used to integrally prepare a φ140×10mm bearing ring. The deformation of the cross-section after punching the rough blank is 40%. The simulation results show that the surface grain size is grade 10. See Figure 5 as shown. In addition, the upsetting ratio is 1.8, the initial profile rolling temperature is controlled at 1120°C, the final profile rolling temperature is controlled at ≥950°C, the actual grain size of the ring is grade 10, and the carbide is arranged along the streamline. See Figure 7 and Figure 8 as shown.

[0110] Example 2

[0111] In this example, a φ200×10mm size specification M50 steel bearing ring is prepared, which mainly includes the following steps:

[0112] Obtaining the measured data of M50 steel: Performance tests are carried out on M50 steel specimens to obtain the measured data of M50 steel. Among them, the measured data of M50 steel include the high-temperature flow stress curve and thermal physical property parameters. Among them, in the temperature range of 900 - 1170°C and the strain rate range of 0.01s -1 -10s -1The stress-strain curve under certain conditions; the thermophysical properties include: the high-temperature diffusion temperature and the specific heat capacity curve, thermal conductivity curve, thermal expansion curve, Young's modulus curve, and Poisson's ratio curve below 1170°C; among them, the high-temperature diffusion temperature ≥ 1600°C.

[0113] Construct a thermomechanical property metallurgical model: Based on the high-temperature flow stress curve, construct a thermomechanical property metallurgical model; among them, the thermomechanical property metallurgical model includes a thermomechanical constitutive equation, a kinetic model of dynamic recrystallization, a grain growth model, and a dislocation density model.

[0114] Among them, the thermomechanical constitutive equation of M50 steel is as follows:

[0115]

[0116] Write the thermomechanical constitutive equation of M50 steel as a function of the Zener-Hollomon parameter, that is:

[0117]

[0118] Strain rate; R: Gas constant, generally taken as 8,314 J / (mol·K); T: Deformation temperature; σ: Peak stress; Z: (Zener-Hollomon) parameter, related to the strain rate.

[0119] Among them, the critical strain for dynamic recrystallization of M50 steel:

[0120] ε c = 0.328ε p = 0.002788×Z 0.1276 ;

[0121] Among them, ε c : Critical strain for dynamic recrystallization; ε p : Peak strain; Z: (Zener-Hollomon) parameter, related to the strain rate.

[0122] Among them, the volume fraction of dynamic recrystallization of M50 steel under different deformation conditions is:

[0123]

[0124] X DRX : Volume fraction of dynamic recrystallization; ε: Strain; ε c : Critical strain for dynamic recrystallization;

[0125] ε p : Peak strain.

[0126] Among them, the dynamic recrystallized grain size model of M50 steel:

[0127] D DRX = 2.6016×10 2 Z -0.14527 ;

[0128] D DRX : Dynamic recrystallized grain size; Z: (Zener - Hollomon) parameter, related to the strain rate.

[0129] Dislocation density model:

[0130]

[0131] h: hardening coefficient; r: radius of the action range of the dislocation stress field; Strain rate; Strain rate trimming coefficient, generally taken as 1; R: gas constant, generally taken as 8,314 J / (mol·K); T: deformation temperature.

[0132] Establish macroscopic and mesoscopic calculation models: Based on the above - mentioned thermal deformation physical metallurgy model, combined with the above - mentioned thermal physical parameters, and coupling with an automatic calculation model, macroscopic and mesoscopic calculation models are established; among them, the macroscopic and mesoscopic calculation models include: simulation calculations of the macroscopic temperature field, stress - temperature field and microstructure of M50 steel under hot deformation conditions, and the change law of the carbide streamline.

[0133] In this step: In the macroscopic finite - element model part, calculation models of the macroscopic finite - element temperature field and stress field during the hot deformation process of the blank are respectively established; in the mesoscopic - scale microstructure evolution model part, the cellular automaton method is mainly introduced to establish a calculation model for microstructure evolution, complete recrystallization calculation and grain size distribution. In addition, through cross - scale simulation calculations, the simulation of carbide streamline arrangement is completed.

[0134] Develop the large deformation rolling process for M50 steel: 1) High-temperature diffusion treatment: Heat the consumable ingot to 1170 °C for high-temperature diffusion until there is no obvious microscopic segregation between dendrites. 2) Forge and bloom the M50 steel billet after high-temperature diffusion treatment into a square billet: The forging ratio ≥ 5, the upsetting reduction ≥ 50%, the deformation temperature is controlled at ≥ 950 °C, and after deformation, an 180 mm × 180 mm × L forged billet (square billet) is prepared, with a grain size of grade 7. The forged billet is detected to have no defects larger than φ1.2 mm. 3) Rolling: Heat the 180 mm × 180 mm × L forged billet (square billet) to 1135 °C, control the final rolling temperature at ≥ 950 °C, and after two deformations with a maximum reduction of 20%, the total cross-sectional deformation is 80%. After multiple deformations, a φ90 mm bar is prepared. Coupling the M50 thermal physical property parameter data and the physical metallurgy model of the thermal deformation behavior with the macroscopic finite element and mesoscopic models, the simulation results show that the grain size is 7.5 grades, the actual detection result is 8 grades, the carbide is grade 3, and there are no defects larger than φ0.8 mm.

[0135] Develop the profile roll expanding process for bearing rings (integrated structure and streamline control of bars and rings): According to the bearing size, determine the required bar size and height by the backward deduction method, and then forward simulate the die forging of the bar in 2 stages to meet the roll expanding height requirement. At this time, it is the rough blank of the ring. Then, according to the streamline requirement, remove the center of the rough blank of the ring to ensure the integrity of the streamline of the remaining part of the bearing outer ring, with a slight change, and then roll expand according to the shape of the raceway. In this case, a φ90 mm bar is used to integrally prepare a φ200 × 10 mm bearing ring. The deformation of the cross-section after punching the rough blank is 40%. The simulation results show that the surface grain size is grade 9. In addition, the upsetting ratio is 1.6, the initial roll expanding temperature is controlled at 1110 °C, the final roll expanding temperature is controlled at ≥ 950 °C, the actual grain size of the ring is 9.5 grades, and the carbide is arranged along the streamline.

[0136] Comparative Example 1

[0137] Prepare an M50 steel bearing ring in Comparative Example 1, which mainly includes the following steps:

[0138] M50 bar rolling process: Heat the consumable ingot to 1180 °C for high-temperature diffusion until there is no obvious microscopic segregation between dendrites; then, the consumable ingot is subjected to forging hot deformation treatment, the forging ratio ≥ 5, the upsetting reduction ≥ 50%, the deformation temperature is controlled at ≥ 950 °C, and after deformation, a 120 mm × 120 mm × L forged billet is prepared, with a grain size of grade 7. The forged billet is detected to have no defects larger than φ1.2 mm. Heat the 120 mm × 120 mm × L forged billet to 1140 °C, control the maximum reduction at more than 10%, and after multiple deformations, a φ75 mm bar is prepared. Coupling the M50 thermal physical property parameter data and the physical metallurgy model of the thermal deformation behavior with the macroscopic finite element and mesoscopic models, the simulation results show that the grain size is 7.5 grades, and there is a mixed grain phenomenon. See Figure 9。The carbide is grade 4, without defects over φ0.8mm.

[0139] Forming process of bearing rings: According to the bearing size, the required rolling bar size and height are determined by the reverse deduction method, and then forward die forging is carried out. Currently, the method of partially removing the center is mainly used, and the streamline control is not considered. Finally, the near-surface carbide of the bearing ring intersects with the ring surface instead of being parallel to it (that is, the carbide does not reach the streamline distribution characteristics), as Figure 10 shown.

[0140] By comparing Example 1 with Comparative Example 1, it can be seen that an intelligent preparation method for M50 steel bearing rings proposed in the embodiment of the present invention can prepare M50 steel bearing rings with excellent microstructure and properties.

[0141] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An intelligent preparation method for an M50 steel bearing raceway, characterized in that It includes the following steps: Obtain the measured data of M50 steel: Conduct performance tests on M50 steel specimens to obtain the measured data of M50 steel; wherein, the measured data of M50 steel includes high-temperature flow stress curves and thermophysical parameters; Construct a thermo-deformation physical metallurgy model: Based on the high-temperature flow stress curves, construct a thermo-deformation physical metallurgy model; wherein, the thermo-deformation physical metallurgy model includes a thermo-deformation constitutive equation, a kinetic model of dynamic recrystallization, a grain growth model, and a dislocation density model; Establish macroscopic and mesoscopic calculation models: Based on the thermo-deformation physical metallurgy model, combined with the thermophysical parameters, and coupled with an automatic calculation model, establish macroscopic and mesoscopic calculation models; wherein, the macroscopic and mesoscopic calculation models include: simulation calculations of the macroscopic temperature field, stress-temperature field, and microstructure of M50 steel under thermo-deformation conditions, and the change law of carbide streamline; Develop the large-deformation rolling process of M50 steel: Based on the macroscopic and mesoscopic calculation models, develop the rolling processes of bars with different specifications and dimensions, and prepare M50 steel bars that meet the set requirements; Develop the profile rolling process of bearing rings: Utilize the M50 steel bars that meet the set requirements and combine simulation calculation methods to develop the profile rolling process of bearing rings, and prepare M50 steel bearing rings that meet the set requirements.

2. The intelligent manufacturing method of the M50 steel bearing raceway according to claim 1, wherein In the step of obtaining the measured data of M50 steel: The M50 steel specimen is an M50 steel consumable electrode ingot specimen; and / or The high-temperature flow stress curve includes: the stress-strain curve under the conditions of a temperature range of 900 - 1170 °C and a strain rate range of 0.01 s -1 -10 s -1 ; and / or The thermophysical parameters include: high-temperature diffusion temperature and specific heat capacity curves, thermal conductivity curves, thermal expansion curves, Young's modulus curves, and Poisson's ratio curves below 1170 °C; preferably, the high-temperature diffusion temperature ≥ 1600 °C.

3. The intelligent manufacturing method of the M50 steel bearing ring according to claim 1 or 2, characterized in that, In the step of establishing macroscopic and mesoscopic calculation models: Couple the macroscopic thermo-deformation with the mesoscopic cellular automata calculation method, and import the thermo-deformation constitutive equation, kinetic model of dynamic recrystallization, grain growth model, and dislocation density model of M50 steel to realize the simulation calculation of refined microstructure control during the bar rolling process; Preferably, based on the thermo-deformation constitutive equation, calculate the thermo-deformation of M50 steel through secondary development in software, and further calculate the change of the microstructure of M50 steel during thermo-deformation through the kinetic model of dynamic recrystallization, grain growth model, and dislocation density model; more preferably, the software selects DEFORM or ABAQUS software; Preferably, for the macroscopic calculation model, calculate models of the macroscopic finite element temperature field and stress field of M50 steel during thermo-deformation are established respectively; for the mesoscopic calculation model, a calculation model of microstructure evolution is established to complete recrystallization calculation and grain size distribution; preferably, through cross-scale simulation calculation, complete the simulation of carbide streamline arrangement.

4. The intelligent manufacturing method of the M50 steel bearing raceway according to any one of claims 1-3, characterized in that, In the step of developing the large-deformation rolling process of M50 steel: If the prepared M50 steel bars do not meet the set requirements, then use the performance data of the bars as correction parameters to correct the thermo-deformation physical metallurgy model, and then correct the macroscopic and mesoscopic calculation models to realize the correction of the developed bar rolling process until M50 steel bars that meet the set requirements are prepared.

5. The intelligent preparation method of the M50 steel bearing ring according to any one of claims 1-4, characterized in that, In the step of developing the large deformation rolling process of M50 steel: The M50 steel bar meeting the set requirements refers to: the streamline control level with a grain size above grade 7.5 and a carbide rating ≤ grade 3.

6. The intelligent preparation method of the M50 steel bearing ring according to any one of claims 1-5, characterized in that, In the step of developing the large deformation rolling process of M50 steel: Before rolling, the following treatments need to be carried out on the M50 steel billet: first, perform a high-temperature diffusion treatment on the M50 steel billet at ≥1160 °C, and then forge and bloom the M50 steel billet after the high-temperature diffusion treatment into a square billet; Preferably, in the process of forging and blooming: the forging ratio ≥5, the upsetting reduction ≥50%, and the deformation temperature is controlled at ≥950 °C; Preferably, the M50 steel billet is an M50 steel consumable ingot billet; more preferably, the cross-section of the M50 steel consumable ingot billet is circular; The square billet needs to have no defects above φ1.2 mm after flaw detection testing, and the grain size needs to be ≥ grade 7.

7. The intelligent preparation method of the M50 steel bearing raceway according to claim 6, characterized in that, In the step of developing the large deformation rolling process of M50 steel: After simulation calculation and correction, the developed bar rolling process is as follows: the initial rolling temperature for rolling the square billet is controlled at 1130 - 1150 °C, the final rolling temperature is controlled at ≥950 °C, the number of times the single-pass deformation of the billet during the initial rolling process exceeds 20% ≥1 time, and the total deformation during the rolling process ≥50%, so that the grain size of the M50 steel bar meets ≥ grade 7.5 and the carbide rating ≤ grade 3.

8. The intelligent preparation method of the M50 steel bearing ring according to any one of claims 1-7, characterized in that, The development of the bearing ring profile rolling process includes the following steps: Step 1) Based on the requirements of ring streamline control, upset the M50 steel bar into a disc-shaped structure; preferably, the upsetting ratio is 1.6 - 2; Step 2) Remove the central area of the disc-shaped structure to ensure that the included angle between the tangents on both sides of the curved streamline in the disc-shaped structure ≥100 degrees, so as to ensure that there is no large-scale bending phenomenon in the remaining streamline; Step 3) Perform profile rolling on the disc-shaped structure with the central area removed according to the shape of the raceway. Among them, the initial profile rolling temperature is controlled at 1100 - 1130 °C, the final profile rolling temperature is controlled at ≥950 °C, and the cross-sectional deformation amount ≥40%.

9. The intelligent manufacturing method of the M50 steel bearing ring according to any one of claims 1-8, characterized in that, The M50 steel bearing ring meeting the set requirements refers to: the M50 steel bearing ring with near-surface carbides arranged along the streamline and a grain size ≥ grade 9; among them, the near-surface carbides refer to the carbides within 500 μm from the surface of the bearing ring.

10. A bearing ring made of M50 steel, characterized in that, The M50 steel bearing ring is prepared by the preparation method of the M50 steel bearing ring according to any one of claims 1 - 9; among them, the near-surface carbides of the M50 steel bearing ring are arranged along the streamline and the grain size ≥ grade 9; among them, the near-surface carbides refer to the carbides within 500 μm from the surface of the bearing ring.

11. A bearing, characterized in that, The bearing includes a bearing inner ring and a bearing outer ring; among them, The bearing inner ring is prepared by the preparation method of the M50 steel bearing ring according to any one of claims 1 - 9; and / or The bearing outer ring is prepared by the preparation method of the M50 steel bearing ring according to any one of claims 1 - 9; Preferably, the service life of the bearing ≥2000 h.

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