A method for finely controlling the high-strength and high-toughness Marbai multiphase microstructure of high-carbon steel bearings

Abstract

This application provides a method for finely controlling the high-strength and high-toughness martensite-bainite multiphase microstructure of high-carbon steel bearings, relating to the field of bearing manufacturing technology. The method includes: in response to a fine-control operation of the martensite multiphase microstructure of a target bearing, obtaining process parameters for austenite grain size and austenite carbon content; based on the austenitizing process parameters, calculating the austenitizing holding temperature and austenitizing holding time corresponding to the target bearing meeting preset process conditions; performing austenitizing process treatment on the target bearing according to the austenitizing holding temperature and austenitizing holding time; performing strength and toughness optimization treatment on the target bearing after austenitizing process treatment, and obtaining the martensite-bainite multiphase microstructure corresponding to the target bearing through strength and toughness optimization treatment. This application solves the problem that blindly increasing the isothermal quenching temperature in pursuit of a short incubation period and high nucleation rate easily leads to coarsening and merging of the lath microstructure, thus degrading performance.

Description

Technical Field

[0001] This application relates to the field of bearing manufacturing technology, and in particular to a method for fine control of the high-strength and high-toughness Marbe multiphase microstructure of high-carbon steel bearings. Background Technology

[0002] GCr15 steel is one of the most widely used bearing steels. Due to its low alloy content and high carbon content, it exhibits high hardness, strength, and wear resistance after conventional martensitic quenching and tempering, making it widely used in the bearing industry. Bearings, as key components providing rotational support, hold an irreplaceable position in aerospace, automotive, and shipbuilding industries. With the continuous development of high-end machine tools and new energy vehicles, traditionally structured GCr15 bearings are finding it increasingly difficult to maintain high fatigue life under current high-speed, high-load, and impact-load service environments. How to improve the strength and toughness of GCr15 bearings to further enhance their fatigue life has become a research challenge for the bearing manufacturing industry.

[0003] To improve the strength and toughness matching of GCr15, the Marble multiphase heat treatment process is often used to introduce bainite in the tough phase. However, the existing multiphase heat treatment only obtains a multiphase structure containing martensite and bainite. In the composite heat treatment process, the microstructure of high-temperature austenite, martensite and bainite is not reasonably and effectively controlled, resulting in the failure to achieve the optimal effect in improving the strength and toughness of bearing steel.

[0004] Therefore, there is an urgent need for a method for finely controlling the high-strength and high-toughness Marbe multiphase microstructure of high-carbon steel bearings. Summary of the Invention

[0005] This application provides a method for finely controlling the high-strength and high-toughness martensite-bainite complex microstructure of high-carbon steel bearings. This method solves the problem that existing complex heat treatments do not reasonably and effectively control the microstructure of austenite, martensite, and bainite at high temperatures during composite heat treatment, resulting in the failure to achieve the optimal effect in improving the strength and toughness of bearing steel.

[0006] The first aspect of this application provides a method for finely controlling the high-strength and high-toughness martensite-bainite multiphase microstructure of a high-carbon steel bearing. The method includes: in response to a fine-control operation of the martensite multiphase microstructure of a target bearing, obtaining austenitizing process parameters, including austenite grain size process parameters and austenite carbon content process parameters; based on the austenitizing process parameters, calculating the austenitizing holding temperature and austenitizing holding time corresponding to the target bearing meeting preset process conditions; performing austenitizing process treatment on the target bearing according to the austenitizing holding temperature and austenitizing holding time; performing strength and toughness optimization treatment on the target bearing after the austenitizing process treatment according to a preset execution order, the strength and toughness optimization treatment including a pre-quenching process operation and an isothermal quenching process operation, the pre-quenching process operation being executed before the isothermal quenching process operation; and obtaining the martensite-bainite multiphase microstructure corresponding to the target bearing through the strength and toughness optimization treatment.

[0007] Optionally, the preset process conditions include a first preset condition, which involves calculating the austenitizing holding temperature corresponding to the target bearing when the preset process conditions are met, based on the austenitizing process parameters. Specifically, this includes calculating the austenitizing holding temperature of the target bearing when the first preset condition is met according to the following formula, wherein the first preset condition is that the austenite grain size of the target bearing is less than or equal to a preset size.

[0008]

[0009] Where D is the process parameter for the austenite grain size, and A is a constant, which can be 2.248 × 10⁻⁶ within the temperature range of 800–1050℃. 16 R is the ideal gas constant, Q A For the activation free energy of austenite transformation, T A The austenitizing holding temperature

[0010] Optionally, the preset process conditions further include a second setting condition, which calculates the austenitizing holding time corresponding to the target bearing meeting the preset process conditions based on the austenitizing process parameters. Specifically, this includes calculating the austenitizing holding time of the target bearing meeting the second setting condition according to the following formula, wherein the second setting condition is that the mass fraction of carbon in the target bearing is less than or equal to a preset percentage.

[0011]

[0012] Among them, t A X is the austenitizing holding time. θX0 is the expected value corresponding to the austenitic carbon content process parameter, β is the initial value corresponding to the austenitic carbon content process parameter, and β is a constant.

[0013] Optionally, the step of performing strength and toughness optimization treatment on the target bearing after the austenitization process according to a preset execution order, wherein performing the pre-quenching process on the target bearing specifically includes: obtaining first quenched martensite volume fraction data; calculating the pre-quenching temperature and pre-quenching time of the target bearing when a third preset condition is met based on the first quenched martensite volume fraction data, wherein the third preset condition is to control the first quenched martensite volume fraction data to be within a first preset volume fraction range; and performing the pre-quenching process on the target bearing according to the pre-quenching temperature and the pre-quenching time.

[0014] Optionally, obtaining the first quenched martensite volume fraction data specifically includes: calculating the first quenched martensite volume fraction data according to the following formula:

[0015] f M =1 - 6.956 × 10 -15 (455-ΔT) 5.32 ;

[0016] Among them, f M The first quenched martensite volume fraction data is given, and ΔT is the difference between the martensite initiation transformation temperature and the pre-quenching temperature.

[0017] Optionally, the step of performing strength and toughness optimization treatment on the target bearing after the austenitization process according to a preset execution order, wherein performing the isothermal quenching process on the target bearing specifically includes: acquiring second quenching martensite volume fraction data and bainite volume fraction data, and calculating the isothermal quenching temperature and isothermal quenching time of the target bearing when a fourth preset condition is met, wherein the fourth preset condition is to control the second quenching martensite volume fraction data to be within a second preset volume fraction range and control the bainite volume fraction data to be within a third preset volume fraction range; and performing the strength and toughness optimization treatment based on the isothermal quenching temperature and the isothermal quenching time.

[0018] Optionally, calculating the isothermal quenching temperature of the target bearing when the fourth preset condition is met specifically includes: obtaining bainite nucleation density data, and calculating the isothermal quenching temperature based on the bainite nucleation density data using the following formula:

[0019]

[0020] Among them, T B N is the isothermal quenching temperature.m V represents the bainitic nucleation density data. m M is a constant. s This is the data for the martensitic transformation initiation temperature.

[0021] Optionally, calculating the isothermal quenching time of the target bearing when the fourth preset condition is met specifically includes: acquiring bainitic phase transformation activation energy data, and calculating the isothermal quenching time based on the bainitic phase transformation activation energy data using the following formula:

[0022]

[0023] Among them, t B f is the isothermal quenching time. B The volume fraction data for bainite is given, where C1 and C2 are both constants. Here are the activation energy data for the bainitic phase transition, where R is the ideal gas constant and T is... B The isothermal quenching temperature is denoted as .

[0024] Optionally, obtaining the second quenched martensite volume fraction data specifically includes: calculating the second quenched martensite volume fraction data according to the following formula:

[0025] f AM =1-f M -f B -f γ -f C ;

[0026] Among them, f AM f represents the volume fraction data of the second quenched martensite. M For the volume fraction data of the first quenched martensite, f B f represents the bainite volume fraction data. γ f represents the volume fraction of retained austenite, and its value can range from 3% to 8%. C This represents the volume fraction of undissolved carbides, and its value can range from 5% to 10%.

[0027] Optionally, obtaining the martensitic-bainitic multiphase structure corresponding to the target bearing through the strength and toughness optimization process specifically includes: obtaining the average lath size data of bainite, and obtaining the martensitic-bainitic multiphase structure corresponding to the target bearing through the strength and toughness optimization process under the condition of satisfying a fifth preset condition, wherein the average lath size data of bainite is less than or equal to a preset size.

[0028] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0029] 1. When a user performs a Marbestite-Bainite dual-phase fine-tuning operation on a target bearing, the system responds to this operation by obtaining austenite grain size and austenite carbon content process parameters. Based on these parameters, it calculates the austenitizing holding temperature and time required to meet the preset process conditions for the target bearing. The system then performs austenitizing treatment on the target bearing according to these parameters. Finally, it optimizes the strength and toughness of the austenitized bearing, obtaining the corresponding martensitic-bainite dual-phase microstructure. This solves the problem that existing dual-phase heat treatments do not effectively control the high-temperature austenite, martensite, and bainite microstructure during composite heat treatment, resulting in suboptimal strength and toughness improvements in bearing steel. This significantly optimizes the strength and toughness matching, wear resistance, and fatigue life of the bearing material.

[0030] 2. By controlling the pre-quenching temperature and ensuring that the volume fraction of the first pre-quenched martensite meets the third preset condition, bainite nucleation can be promoted and space can be reserved for bainite growth.

[0031] 3. By acquiring the volume fraction data of the second quenched martensite and the volume fraction data of bainite, and calculating the isothermal quenching temperature and isothermal quenching time of the target bearing when the fourth preset condition is met, the volume fraction data of the first quenched martensite, the volume fraction data of the second quenched martensite, and the volume fraction data of bainite are controlled within the corresponding volume fraction range, thereby achieving optimized matching of strength and toughness properties. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating a method for finely controlling the high-strength and high-toughness Marble multiphase microstructure of a high-carbon steel bearing, as provided in an embodiment of this application.

[0033] Figure 2 This is a schematic diagram of the temperature change for optimizing the multiphase strength and toughness of Mabey bearings, provided in an embodiment of this application.

[0034] Figure 3 This is a schematic diagram comparing the tensile and impact property control effects provided in the embodiments of this application with the traditional martensitic quenching and tempering process. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0036] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0037] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0038] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] Please refer to Figure 1 The diagram illustrates a process flow chart of a method for finely controlling the high-strength and high-toughness Marbe multiphase microstructure of a high-carbon steel bearing, provided in an embodiment of this application. The process flow chart mainly includes the following steps: S101 to S105.

[0040] Step S101: In response to the Marbe polyphase fine control operation for the target bearing, austenitization process parameters are obtained, including austenite grain size process parameters and austenite carbon content process parameters.

[0041] Specifically, when a user responds to a fine-tuning operation of the Mabetian phase for a target bearing, austenitizing process parameters are obtained. These parameters include austenite grain size and austenite carbon content. To ensure rapid nucleation and growth of bainite during subsequent heat treatment, the high-temperature austenite in the target bearing needs to have fine grains and controllable carbon content. Furthermore, the promoting effect of rolling deformation on carbide dissolution and the inhibiting effect on grain growth must be fully considered. This invention calculates the grain size and austenite carbon content process parameters of the target bearing with a rolling deformation amount of ε after different isothermal quenching temperatures and times, based on formulas, and ultimately determines an austenitizing process that satisfies a grain size ≤10μm and an austenite carbon content ≤0.6%.

[0042] Step S102: Based on the austenitizing process parameters, calculate the austenitizing holding temperature and austenitizing holding time corresponding to the target bearing meeting the preset process conditions.

[0043] Specifically, the austenitizing holding temperature of the target bearing when the first preset condition is met is calculated according to the following formula, wherein the first preset condition is that the austenite grain size of the target bearing is less than or equal to a preset size.

[0044]

[0045] Where D is the process parameter for the austenite grain size, and A is a constant, which can be 2.248 × 10⁻⁶ within the temperature range of 800–1050℃. 16 R is the ideal gas constant, Q A For the activation free energy of austenite transformation, T A The austenitizing holding temperature;

[0046] The austenitizing holding time of the target bearing when the second condition is met is calculated according to the following formula, wherein the second condition is that the mass fraction of carbon in the target bearing is less than or equal to a preset percentage.

[0047]

[0048] Among them, t A X is the austenitizing holding time. θ X0 is the expected value corresponding to the austenitic carbon content process parameter, β is the initial value corresponding to the austenitic carbon content process parameter, and β is a constant.

[0049] Step S103: Perform austenitizing process on the target bearing according to the austenitizing holding temperature and the austenitizing holding time.

[0050] Step S104: According to the preset execution sequence, the target bearing after the austenitization process is subjected to strength and toughness optimization treatment.

[0051] Specifically, a high-efficiency bainitic phase transformation is achieved by using a strength and toughness optimization treatment. The strength and toughness optimization treatment includes a pre-quenching process and an isothermal quenching process. The pre-quenching process is performed before the isothermal quenching process.

[0052] In one possible implementation, step S104 further includes: acquiring first quenched martensite volume fraction data; calculating the pre-quenching temperature and pre-quenching time of the target bearing when a third preset condition is met based on the first quenched martensite volume fraction data, wherein the third preset condition is controlling the first quenched martensite volume fraction data to be within a first preset volume fraction range; and performing the pre-quenching process operation on the target bearing according to the pre-quenching temperature and the pre-quenching time.

[0053] Specifically, by controlling the pre-quenching temperature and ensuring the volume fraction of the first pre-quenched martensite meets the third preset condition (i.e., controlling the volume fraction of the first pre-quenched martensite between 5% and 15%), bainite nucleation can be promoted and space can be reserved for bainite growth. The pre-quenching temperature and pre-quenching time of the target bearing when the third preset condition is met are calculated, and the volume fraction data of the first quenched martensite is calculated according to the following formula:

[0054] f M =1 - 6.956 × 10 -15 (455-ΔT) 5.32 ;

[0055] Among them, f M The first quenched martensite volume fraction data is given, and ΔT is the difference between the martensite initiation transformation temperature and the pre-quenching temperature.

[0056] In one possible implementation, step S104 further includes: acquiring second quenched martensite volume fraction data and bainite volume fraction data, and calculating the isothermal quenching temperature and isothermal quenching time of the target bearing when a fourth preset condition is met, wherein the fourth preset condition is to control the second quenched martensite volume fraction data to be within a second preset volume fraction range and control the bainite volume fraction data to be within a third preset volume fraction range; and performing the strength and toughness optimization processing based on the isothermal quenching temperature and the isothermal quenching time.

[0057] Specifically, the volume fraction data of the second quenched martensite and the volume fraction data of bainite are obtained, and the isothermal quenching temperature and isothermal quenching time of the target bearing when the fourth preset condition is met are calculated. This means controlling the volume fraction data of the first quenched martensite, the second quenched martensite, and the bainite to be within their respective volume fraction ranges, thereby achieving optimized matching of strength and toughness. Specifically, the volume fraction range corresponding to the first quenched martensite is 10%–15%, the volume fraction range corresponding to the first quenched martensite is 30%–35%, and the volume fraction range corresponding to the bainite is 40%–45%. The bainite nucleation density data is obtained, and based on the bainite nucleation density data, the isothermal quenching temperature is calculated using the following formula:

[0058]

[0059] Among them, T B N is the isothermal quenching temperature. m V represents the bainitic nucleation density data. m M is a constant. sThe data represents the martensitic transformation initiation temperature. The bainitic transformation activation energy data is obtained, and based on this data, the isothermal quenching time is calculated using the following formula:

[0060]

[0061] Among them, t B f is the isothermal quenching time. B The volume fraction data for bainite is given, where C1 and C2 are both constants. Here are the activation energy data for the bainitic phase transition, where R is the ideal gas constant and T is... B The isothermal quenching temperature is given. The volume fraction of the second quenched martensite is calculated using the following formula:

[0062] f AM =1-f M -f B -f γ -f C ;

[0063] Among them, f AM f represents the volume fraction data of the second quenched martensite. M For the volume fraction data of the first quenched martensite, f B f represents the bainite volume fraction data. γ f represents the volume fraction of retained austenite, and its value can range from 3% to 8%. C This represents the volume fraction of undissolved carbides, and its value can range from 5% to 10%.

[0064] Step S105: Through the strength and toughness optimization treatment, the martensitic-bainitic multiphase structure corresponding to the target bearing is obtained.

[0065] For details, please refer to Figure 2 The document presents a schematic diagram illustrating the temperature variation for optimizing the multiphase strength and toughness of high-carbon steel bearings, as provided in an embodiment of this application.

[0066] In one possible implementation, step S105 further includes: obtaining average bainite lath size data, and under the condition of satisfying a fifth preset condition, obtaining the martensitic-bainite multiphase structure corresponding to the target bearing through the strength and toughness optimization process, wherein the fifth preset condition is that the average bainite lath size data is less than or equal to a preset size.

[0067] Specifically, in order to precisely control the size of the bainitic laths, the upper limit of the isothermal time to satisfy the fifth preset condition is calculated based on the following formula:

[0068]

[0069] Among them, l B The values ​​represent the average lath dimensions of bainite, where V0 is the pre-exponential factor and V0 = 30 m / s, and k is the Boltzmann constant and k = 1.380649 × 10⁻⁶. -23 J / K.

[0070] Taking a high-speed machine tool bearing ring of GCr15 material as an example, its initial microstructure is in the spheroidized annealed state. The fine control of its high-strength and high-toughness Marbe multiphase microstructure is achieved through the following steps:

[0071] S1. Control of austenitizing process parameters: The bearing rings are austenitized in a vacuum atmosphere furnace. The bearing is heated to 845℃ and held for 20 minutes.

[0072] S2. Pre-quenching process parameter control: Temperature-controlled pre-quenching is carried out in a constant temperature salt bath furnace. The quenching medium is 45% sodium nitrite + 55% potassium nitrate. The final pre-quenching process parameters are determined to be 200℃ / 5min.

[0073] S3. Isothermal Quenching Process Parameter Control: Isothermal quenching was performed in a constant-temperature salt bath furnace using a quenching medium of 45% sodium nitrite + 55% potassium nitrate. The final isothermal quenching process parameters were determined to be 200℃ / 5min. After isothermal quenching, the sample was transferred to a constant-temperature oil bath furnace for final martensitic quenching using QJ22-32 high-speed bright quenching oil at a quenching temperature of 70℃.

[0074] Through precise control of the high-strength and high-toughness marbailon multiphase microstructure, the volume fractions of primary quenched martensite, bainite, and secondary quenched martensite obtained were 13.6%, 54.3%, and 27.5%, respectively, meeting the microstructure control target. Furthermore, the average lath width was 0.39 μm, indicating that the marbailon multiphase microstructure was effectively refined.

[0075] Please refer to Figure 3 The document presents a schematic diagram comparing the tensile and impact performance control effect provided by the embodiments of this application with that of the traditional martensitic quenching and tempering process. Through standard U-notch Charpy impact testing, the impact absorption energy increased from 6.8J to 12.3J, an increase of approximately 80%. In the traditional process, cracks propagate rapidly within bulk martensite with relatively straight profiles. This technology significantly increases the number of multiphase interfaces in the matrix and significantly reduces the content of hard and brittle martensite, resulting in a much more tortuous crack propagation path. The embodiments demonstrate that the present invention can significantly optimize the strength and toughness matching of GCr15 bearings.

[0076] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0077] In the various embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between apparatuses or units may be electrical or other forms.

[0078] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0079] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0080] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0081] The above description is merely an exemplary embodiment disclosed in this application and should not be construed as limiting the scope of this application. Any equivalent changes and modifications made in accordance with the teachings of this application shall still fall within the scope of this application. Those skilled in the art, upon considering the disclosure of the specification and practical truths, will readily conceive of other embodiments disclosed in this application.

[0082] This application is intended to cover any variations, uses, or adaptations disclosed herein that follow the general principles disclosed herein and include common knowledge or customary technical means in the art that are not described in this application.

Claims

1. A method for finely controlling the high-strength and high-toughness Marbe multiphase microstructure of high-carbon steel bearings, characterized in that, The method includes: In response to the Mabe multiphase fine control operation for the target bearing, austenitization process parameters are obtained, including austenite grain size process parameters and austenite carbon content process parameters. Based on the austenitizing process parameters, calculate the austenitizing holding temperature and austenitizing holding time corresponding to the target bearing meeting the preset process conditions; The target bearing is subjected to austenitization process based on the austenitization holding temperature and the austenitization holding time. According to the preset execution order, the target bearing after the austenitization process is subjected to strength and toughness optimization treatment. The strength and toughness optimization treatment includes pre-quenching process operation and isothermal quenching process operation. The execution order of the pre-quenching process operation is before the isothermal quenching process operation. Through the aforementioned strength and toughness optimization treatment, the martensitic-bainitic multiphase microstructure corresponding to the target bearing is obtained; The preset process conditions include a first preset condition. Based on the austenitizing process parameters, the austenitizing holding temperature corresponding to the target bearing meeting the preset process conditions is calculated. Specifically, this includes calculating the austenitizing holding temperature of the target bearing meeting the first preset condition according to the following formula, where the first preset condition is that the austenite grain size of the target bearing is less than or equal to a preset size: ； in, The process parameters for the austenite grain size are as follows. It is a constant, and it is within the range of 800~1050℃. Take 2.248×10 16 , Let be the ideal gas constant. The activation free energy for austenite transformation The austenitizing holding temperature; The preset process conditions also include a second preset condition. Based on the austenitizing process parameters, the austenitizing holding time corresponding to the target bearing meeting the preset process conditions is calculated. Specifically, this includes: calculating the austenitizing holding time of the target bearing meeting the second preset condition according to the following formula, where the second preset condition is that the carbon element mass fraction of the target bearing is less than or equal to a preset percentage: ； in, The austenitizing holding time is [not specified]. This represents the expected value corresponding to the austenitic carbon content process parameter. This refers to the initial value corresponding to the austenitic carbon content process parameter. It is a constant; The step involves optimizing the strength and toughness of the target bearing after the austenitization process according to a preset execution sequence. Specifically, the pre-quenching process for the target bearing includes: acquiring first pre-quenched martensite volume fraction data; calculating the pre-quenching temperature and pre-quenching time of the target bearing when a third preset condition is met, based on the first pre-quenched martensite volume fraction data, wherein the third preset condition is controlling the first pre-quenched martensite volume fraction data within a first preset volume fraction range; and performing the pre-quenching process on the target bearing according to the pre-quenching temperature and the pre-quenching time. The step involves optimizing the strength and toughness of the target bearing after the austenitization process according to a preset execution sequence. Specifically, the isothermal quenching process includes: acquiring second pre-quenched martensite volume fraction data and bainite volume fraction data; calculating the isothermal quenching temperature and time for the target bearing when a fourth preset condition is met; the fourth preset condition being that the second pre-quenched martensite volume fraction data is within a second preset volume fraction range, and the bainite volume fraction data is within a third preset volume fraction range; and performing the strength and toughness optimization process based on the isothermal quenching temperature and time. The martensitic-bainitic complex structure corresponding to the target bearing is obtained through the strength and toughness optimization process. Specifically, this includes: obtaining the average lath size data of bainite, and obtaining the martensitic-bainitic complex structure corresponding to the target bearing through the strength and toughness optimization process under the fifth preset condition, wherein the average lath size data of bainite is less than or equal to a preset size.

2. The method according to claim 1, characterized in that, The acquisition of the first pre-quenched martensite volume fraction data specifically includes: The volume fraction of the first pre-quenched martensite was calculated using the following formula: ； in, This refers to the volume fraction data of the first pre-quenched martensite. It is the difference between the martensitic initiation transformation temperature and the pre-quenching temperature.

3. The method according to claim 1, characterized in that, Calculating the isothermal quenching temperature of the target bearing when the fourth preset condition is met specifically includes: Obtain the bainite nucleation density data, and calculate the isothermal quenching temperature based on the bainite nucleation density data using the following formula: ； in, The isothermal quenching temperature is... The bainite nucleation density data, It is a constant. This is the data for the martensitic transformation initiation temperature.

4. The method according to claim 1, characterized in that, Calculating the isothermal quenching time of the target bearing when the fourth preset condition is met specifically includes: Obtain the bainitic phase transformation activation energy data, and calculate the isothermal quenching time based on the bainitic phase transformation activation energy data using the following formula: ； in, The isothermal quenching time is... The bainite volume fraction data is as follows. and All are constants. This refers to the activation energy data for the bainitic phase transformation. Let be the ideal gas constant. The isothermal quenching temperature is denoted as .

5. The method according to claim 1, characterized in that, The acquisition of the second pre-quenched martensite volume fraction data specifically includes: The volume fraction of the second pre-quenched martensite is calculated using the following formula: ； in, This refers to the volume fraction data of the second pre-quenched martensite. This refers to the volume fraction data of the first pre-quenched martensite. The bainite volume fraction data is as follows. This represents the volume fraction of retained austenite, and its value ranges from 3% to 8%. This represents the volume fraction of undissolved carbides, and its value ranges from 5% to 10%.

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