Bearing ring heat treatment process based on residual stress optimization

Abstract

The bearing ring heat treatment process based on residual stress optimization comprises the following steps that S1, the surface of a bearing ring is cleaned, and it is ensured that the surface of the bearing ring is clean and free of oil stains and impurities; s2, sectional type heating treatment is conducted on the bearing ring, and the bearing ring is heated to the preset heat treatment temperature; s3, the bearing ring subjected to heat treatment is rapidly put into a quenching medium to be rapidly cooled; s4, the quenched bearing ring is subjected to tempering treatment; s5, the bearing ring subjected to tempering treatment is subjected to cooling treatment.The bearing ring heat treatment process can adjust stress distribution in the bearing ring, the cracking risk caused by stress concentration is reduced, generation of residual stress is reduced, release of the residual stress is promoted, the uniformity of residual stress distribution is improved, and the service life of the bearing ring is prolonged. And the residual stress can be effectively reduced, the toughness is improved, the structure is refined and the stability is improved, so that the quality and the service life of the bearing are improved.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment of bearing rings, and in particular to a heat treatment process of bearing rings based on residual stress optimization. Background Art

[0002] As an important part of the bearing, the quality and performance of the bearing ring directly affect the working accuracy, life and reliability of the bearing. Under high-speed, heavy-load and high-precision working conditions, the bearing ring needs to have good strength, hardness, toughness and dimensional stability.

[0003] Traditional bearing ring heat treatment processes, such as quenching and tempering, can improve the hardness and strength of the rings, but they will also produce large residual stress inside the rings. The residual stress can easily cause the rings to deform, crack, and other problems during subsequent use, reducing the service life and reliability of the bearings.

[0004] During the heat treatment process, due to the uneven heating of the bearing ring, different degrees of thermal stress will be generated on the surface and core of the ring. During the tempering process, if the temperature and time are not properly controlled, the residual stress may not be fully eliminated.

[0005] Therefore, the present application proposes a bearing ring heat treatment process based on residual stress optimization. Summary of the invention

[0006] The purpose of the present invention is to provide a bearing ring heat treatment process based on residual stress optimization to solve the technical problem of residual stress existing in the existing bearing ring heat treatment process.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A bearing ring heat treatment process based on residual stress optimization comprises the following steps:

[0009] S1. Clean the surface of the bearing ring and ensure that it is clean and free of oil and impurities;

[0010] S2, performing a segmented heat treatment on the bearing ring, heating the bearing ring to a predetermined heat treatment temperature;

[0011] S3, quickly placing the heat-treated bearing ring into a quenching medium for rapid cooling;

[0012] S4, tempering the quenched bearing ring;

[0013] S5. Cooling the bearing ring after tempering.

[0014] As a further solution of the present invention, in S1, cleaning the surface of the bearing ring is divided into three stages, the first stage is mechanical cleaning, the second stage is chemical cleaning, and the third stage is solvent cleaning.

[0015] Mechanical cleaning includes sand blasting. The sand blasting particle size is selected as 50-70 mesh quartz sand. The surface of the ring is fully covered by the sand blasting at a certain pressure and angle to ensure full coverage without damaging the surface of the ring.

[0016] Chemical cleaning includes cleaning with a dilute hydrochloric acid solution. During the pickling process, the temperature of the dilute hydrochloric acid solution is between 20-60°C and the pickling time is 10 to 30 minutes.

[0017] Solvent cleaning includes alcohol cleaning, the alcohol cleaning temperature is 20-45°C, and the cleaning time is 10 to 20 minutes.

[0018] As a further solution of the present invention, in S2, the bearing ring is subjected to a segmented heating treatment including a primary heating, a secondary heating and a tertiary heating.

[0019] The primary heating includes placing the bearing ring in a heating furnace and heating it to 80-100°C, and keeping the bearing ring warm for 1-1.5 minutes per millimeter of thickness.

[0020] The secondary heating includes raising the temperature of the bearing ring to 300-320°C and keeping it warm for 1-1.5 minutes per millimeter of thickness.

[0021] The three heating steps include heating the bearing ring to 820-860°C and keeping the temperature for 1-1.5 minutes per millimeter of thickness.

[0022] As a further solution of the present invention, in S3, the bearing ring is quenched and cooled by using a salt bath. The bearing ring is quickly taken out from the heating furnace after the holding time is reached and placed vertically in a quenching salt bath tank. The bearing ring is kept stable when entering the water to avoid collision between the bearing ring and the water tank wall or excessive splashes. The temperature of the salt bath is controlled at 180-220°C and the cooling time is 5 to 15 minutes.

[0023] As a further solution of the present invention, the temperature of the bearing ring after quenching and cooling is 20-40°C.

[0024] As a further solution of the present invention, in S4, the tempering treatment of the bearing ring includes primary tempering and secondary tempering.

[0025] The first tempering includes placing the bearing ring in a tempering furnace for tempering heating. The first tempering temperature is 150-170°C and the insulation time is 3 to 4 hours.

[0026] The secondary tempering includes placing the bearing ring in a tempering furnace for secondary tempering heating. The secondary tempering temperature is 180-210°C and the insulation time is 3 to 4 hours.

[0027] As a preferred embodiment of the present invention, in S5, the bearing ring after the tempering treatment is cooled by furnace cooling.

[0028] As a further preferred embodiment of the present invention, argon gas is introduced into the tempering furnace during the cooling process of the bearing ring.

[0029] As a further preferred embodiment of the present invention, a spacing distance is left between the bearing rings in the tempering furnace, and the spacing distance is not less than 1 cm.

[0030] As a further preferred embodiment of the present invention, a plurality of thermocouples are installed inside the tempering furnace, and the plurality of thermocouples are evenly installed at different positions inside the tempering furnace.

[0031] Compared with the prior art, the bearing ring heat treatment process based on residual stress optimization of the present invention has the following beneficial effects:

[0032] 1. The segmented heating can avoid the bearing ring from being subjected to drastic temperature changes in a short period of time. The bearing ring has enough time to adapt to the temperature changes, thereby reducing the generation of thermal stress. The stress distribution inside the ring can be adjusted to make it more uniform, reducing the risk of cracking caused by stress concentration. The segmented heating treatment of the bearing ring has a positive effect on the residual stress, which can reduce the generation of residual stress, promote the release of residual stress, and improve the uniformity of residual stress distribution, thereby improving the quality and performance of the bearing ring.

[0033] 2. Through the first tempering, the bearing ring can be kept warm at a certain temperature, which promotes the change of internal structure and reduces the residual stress. This helps to improve the dimensional stability of the ring and reduce the risk of deformation and cracking caused by stress release in the subsequent use. The second tempering can further promote the release of residual stress on the basis of the first tempering, so that the stress level of the ring is lower. The coordinated use of the first tempering and the second tempering can effectively reduce the residual stress, improve the toughness, refine the structure and improve the stability, thereby improving the quality and service life of the bearing.

[0034] 3. By using a salt bath to quench the bearing ring, the salt bath has a high cooling rate and good uniformity, and the temperature of the salt bath can be precisely controlled. When the bearing ring is quenched, the salt bath can quickly transfer heat to the inside and outside of the bearing ring, making the temperature of the entire ring uniform, thereby reducing the thermal stress and deformation caused by uneven temperature. Placing the bearing ring vertically in the quenching medium can ensure that all parts of the bearing ring are evenly in contact with the salt bath, avoiding uneven cooling caused by tilting or laying flat.

[0035] 4. Furnace cooling can minimize the residual stress in the bearing ring because the temperature changes very slowly and the temperature gradient between the inside and outside of the ring is very small, which helps to make the internal structure of the bearing ring more uniform and further reduce the residual stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only examples of the embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 The process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] In the description of the embodiments of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the embodiments of the present invention.

[0040] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can be the internal connection of two components; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0041] See also Figure 1 As shown, a bearing ring heat treatment process based on residual stress optimization according to an embodiment of the present invention comprises the following steps:

[0042] S1. Clean the surface of the bearing ring and ensure that it is clean and free of oil and impurities;

[0043] S2, performing a segmented heat treatment on the bearing ring, heating the bearing ring to a predetermined heat treatment temperature;

[0044] S3, quickly placing the heat-treated bearing ring into a quenching medium for rapid cooling;

[0045] S4, tempering the quenched bearing ring;

[0046] S5. Cooling the bearing ring after tempering.

[0047] In S1, the cleaning of the bearing ring surface is divided into three stages: the first stage is mechanical cleaning, the second stage is chemical cleaning, and the third stage is solvent cleaning.

[0048] Mechanical cleaning includes sand blasting. The sand blasting particle size is selected as 50-70 mesh quartz sand. The surface of the ring is fully covered by the sand blasting at a certain pressure and angle to ensure full coverage without damaging the surface of the ring.

[0049] Chemical cleaning includes cleaning with a dilute hydrochloric acid solution. During the pickling process, the temperature of the dilute hydrochloric acid solution is between 20-60°C and the pickling time is 10 to 30 minutes.

[0050] Solvent cleaning includes alcohol cleaning, the alcohol cleaning temperature is 20-45°C, and the cleaning time is 10 to 20 minutes.

[0051] By first using mechanical cleaning to remove the more stubborn attachments such as scale, rust and old coating on the surface of the bearing ring, and then using chemical cleaning to remove the fine oxides that are difficult to completely remove by mechanical cleaning, it is ensured that the residual oxides and rust on the surface can be completely removed. Solvent cleaning effectively removes the residual oil on the surface of the bearing ring, ensures the cleanliness of the surface of the bearing ring, provides the best surface state for the heat treatment process, and avoids foreign matter on the surface of the bearing ring causing the cooling speed and cooling uniformity of the bearing ring. The sand particles are preferably 60 mesh quartz sand, which can effectively remove the more stubborn attachments such as scale, rust and old coating on the surface of the bearing ring. The temperature of the hydrochloric acid solution is preferably 50°C, and the pickling time is preferably 25 minutes, which can effectively remove the residual oxides and rust on the surface. The alcohol cleaning temperature is preferably 35°C, which can effectively remove the residual oil on the surface of the bearing ring.

[0052] Specific parameters of quartz sand injection pressure:

[0053] Low pressure range: For relatively weak ferrule materials or occasions with extremely high surface quality requirements, the injection pressure may be set in a lower range, such as 0.2~0.4MPa.

[0054] Medium pressure range: For most conventional bearing ring cleaning tasks, the jet pressure is usually set in the medium range, such as 0.4-0.6 MPa. The pressure within this range can effectively remove dirt and attachments while avoiding excessive damage to the ring surface.

[0055] High pressure range: For particularly stubborn dirt or large-area ferrules that need to be cleaned quickly, the spray pressure may be set at a higher range, such as 0.6-0.8 MPa. However, please note that excessively high pressure may increase the risk of damage to the ferrule surface.

[0056] Specific parameters of quartz sand spraying angle:

[0057] Conventional angle: Usually, the spray angle is set between 30° and 60°. Angles within this range can make the sand particles evenly and comprehensively cover the surface of the ring, while avoiding excessive impact and damage caused by vertical spraying.

[0058] Special Angles: For some special cleaning tasks or ferrule shapes, the spray angle may need to be adjusted to suit different cleaning needs. For example, for hard-to-reach corners or edge areas, a smaller angle may be required for spraying.

[0059] The above parameters are not fixed values. In actual operation, they should be adjusted and optimized according to specific conditions. At the same time, in order to ensure the cleaning effect and avoid damage to the surface of the ring, a small-scale trial sandblasting test is carried out before formal cleaning, and the spray pressure and angle are adjusted according to the test results.

[0060] In S2, the bearing ring is subjected to a segmented heating treatment including primary heating, secondary heating and tertiary heating; wherein the primary heating includes first placing the bearing ring in a heating furnace and heating it to 80-100° C., and keeping the bearing ring warm for 1-1.5 minutes per millimeter of thickness.

[0061] The secondary heating includes heating the bearing ring to 300-320°C and keeping it warm for 1-1.5 minutes per millimeter of thickness; the tertiary heating includes heating the bearing ring to 820-860°C and keeping it warm for 1-1.5 minutes per millimeter of thickness.

[0062] The above-mentioned segmented heating avoids the bearing ring from being subjected to drastic temperature changes in a short period of time. The bearing ring has enough time to adapt to the temperature changes, thereby reducing the generation of thermal stress. The stress distribution inside the ring can be adjusted to make it more uniform, reducing the risk of cracking due to stress concentration. The segmented heating treatment of the bearing ring has a positive effect on the residual stress, which can reduce the generation of residual stress, promote the release of residual stress, and improve the uniformity of residual stress distribution, thereby improving the quality and performance of the bearing ring.

[0063] In S3, the bearing ring is quenched and cooled by using a salt bath. The bearing ring is quickly taken out from the heating furnace after the holding time is reached, and is placed vertically in a quenching salt bath tank. The bearing ring is kept stable when entering the water to avoid collision between the bearing ring and the water tank wall or excessive splashes. The temperature of the salt bath is controlled at 180-220°C, and the cooling time is 5 to 15 minutes. The temperature of the salt bath is preferably 190°C, and the cooling time is preferably 10 minutes. The salt bath has a high cooling rate and good uniformity, and the temperature of the salt bath can be precisely controlled. When the bearing ring is quenched, the salt bath can quickly transfer heat to the inside and outside of the bearing ring, so that the temperature of the entire ring is uniform, thereby reducing thermal stress and deformation caused by uneven temperature. Placing the bearing ring vertically in the quenching medium can ensure that all parts of the bearing ring are evenly in contact with the salt bath, avoiding uneven cooling caused by tilting or laying flat.

[0064] The temperature of the bearing ring after quenching is 20-40℃. Within this temperature range, the bearing ring has completed the rapid cooling during the quenching process and formed a martensitic structure, which significantly improves the hardness of the bearing ring and enhances its wear resistance and fatigue resistance.

[0065] In S4, the tempering treatment of the bearing ring includes primary tempering and secondary tempering; wherein the primary tempering includes placing the bearing ring in a tempering furnace for primary tempering heating, the primary tempering temperature is 150-170°C, and the holding time is 3-4 hours; the secondary tempering includes placing the bearing ring in a tempering furnace for secondary tempering heating, the secondary tempering temperature is 180-210°C, and the holding time is 3-4 hours, the primary tempering temperature is preferably 160°C, the holding time is preferably 3.5 hours, the secondary tempering temperature is preferably 200°C, and the holding time is preferably 3. 5 hours, the first tempering can keep the bearing ring at a certain temperature, promote the change of internal structure, thereby reducing residual stress, which helps to improve the dimensional stability of the ring and reduce the risk of deformation and cracking caused by stress release in subsequent use. The second tempering can further promote the release of residual stress on the basis of the first tempering, so that the stress level of the ring is lower. Through the coordinated use of the first tempering and the second tempering, the residual stress can be effectively reduced, the toughness can be improved, the structure can be refined and the stability can be improved, thereby improving the quality and service life of the bearing.

[0066] In S5, the cooling method for the bearing ring after tempering is furnace cooling. Furnace cooling can reduce the residual stress of the bearing ring to the greatest extent. Because the temperature changes very slowly, the temperature gradient between the inside and outside of the ring is very small, which helps to make the internal structure of the bearing ring more uniform and further reduce the residual stress.

[0067] During the cooling process of the bearing ring, argon gas is introduced into the tempering furnace. Argon gas can form a protective gas film on the surface of the bearing ring to prevent oxygen from contacting the bearing ring, thereby maintaining the surface finish and dimensional accuracy of the ring and preventing oxidation. It can also inhibit the diffusion of carbon elements from the surface of the bearing ring into the air, thereby reducing the thickness of the decarburized layer and improving the quality of the bearing ring. In addition, argon gas has a low thermal conductivity, which can slow down the cooling rate of the bearing ring and make the bearing ring cool evenly in the furnace, which helps to reduce the temperature gradient inside the bearing ring, reduce residual stress, and improve the dimensional stability of the ring.

[0068] There is a spacing distance between each bearing ring in the tempering furnace, which is not less than 1cm. The bearing rings should maintain an appropriate spacing distance to ensure air circulation and uniform heat distribution. If the spacing distance is too small, it will affect the cooling effect and increase residual stress. If the spacing distance is too large, it will waste space in the furnace and reduce production efficiency.

[0069] There are multiple thermocouples installed inside the tempering furnace, and the multiple thermocouples are evenly installed at different positions inside the tempering furnace. By installing thermocouples at multiple different positions, the temperature conditions of various areas in the tempering furnace can be fully monitored, providing operators with more detailed temperature information, which can ensure that each bearing ring can get the same heat treatment effect during the tempering process, thereby improving the quality stability of the product.

[0070] The working principle of the embodiment of the present invention is as follows: first, mechanical cleaning is used to remove the more stubborn attachments such as scale, rust and old coating on the surface of the bearing ring, and then chemical cleaning is used to remove the fine oxides that are difficult to completely remove by mechanical cleaning, ensuring that the residual oxides and rust on the surface can be completely removed. Finally, solvent cleaning is used to effectively remove the residual oil on the surface of the bearing ring, ensuring the cleanliness of the surface of the bearing ring, providing the best surface state for the heat treatment process, and avoiding foreign matter on the surface of the bearing ring causing the cooling speed and cooling uniformity of the bearing ring.

[0071] The bearing ring is placed in a heating furnace and heated to 80-100°C, and is kept warm for 1-1.5 minutes per millimeter thickness of the bearing ring. After the first insulation time is completed, a second heating is performed, which includes heating the bearing ring to 300-320°C and keeping it warm for 1-1.5 minutes per millimeter thickness of the bearing ring. After the second insulation time is completed, a third heating is performed, which includes heating the bearing ring to 820-860°C and keeping it warm for 1-1.5 minutes per millimeter thickness of the bearing ring. The three-stage heating avoids the bearing ring from being subjected to drastic temperature changes in a short period of time. The bearing ring has enough time to adapt to the temperature changes, thereby reducing the generation of thermal stress, and can adjust the stress distribution inside the ring to make it more uniform, reducing the risk of cracking caused by stress concentration. The segmented heating treatment of the bearing ring has a positive effect on the residual stress, can reduce the generation of residual stress, promote the release of residual stress, and improve the uniformity of residual stress distribution, thereby improving the quality and performance of the bearing ring.

[0072] After the bearing ring insulation time is completed, the bearing ring is quickly taken out of the heating furnace and placed vertically in the quenching salt bath tank. The bearing ring should remain stable when entering the water to avoid collision between the bearing ring and the water tank wall or excessive splashes. The temperature of the salt bath is controlled at 180-220℃, and the cooling time is 5 to 15 minutes. The salt bath has a high cooling rate and good uniformity, and the temperature of the salt bath can be precisely controlled. When the bearing ring is quenched, the salt bath can quickly transfer heat to the inside and outside of the bearing ring, so that the temperature of the entire ring is uniform, thereby reducing the thermal stress and deformation caused by uneven temperature. Placing the bearing ring vertically in the quenching medium can ensure that all parts of the bearing ring are evenly in contact with the salt bath, avoiding uneven cooling caused by tilting or laying flat.

[0073] The bearing ring is tempered, and the bearing ring is placed in a tempering furnace for primary tempering heating. The primary tempering temperature is 150-170℃, and the holding time is 3 to 4 hours. The secondary tempering includes placing the bearing ring in a tempering furnace for secondary tempering heating. The secondary tempering temperature is 180-210℃, and the holding time is 3 to 4 hours. The primary tempering can keep the bearing ring at a certain temperature, promote changes in the internal structure, and thus reduce residual stress, which helps to improve the dimensional stability of the ring and reduce the risk of deformation and cracking caused by stress release during subsequent use. The secondary tempering can further promote the release of residual stress on the basis of the first tempering, so that the stress level of the ring is lower. Through the coordinated use of primary and secondary tempering, the residual stress can be effectively reduced, the toughness can be improved, the structure can be refined, and the stability can be improved, thereby improving the quality and service life of the bearing.

[0074] The bearing ring after tempering is cooled by furnace cooling. Argon is introduced into the tempering furnace during the cooling process. Argon can form a protective gas film on the surface of the bearing ring to prevent oxygen from contacting the bearing ring, thereby maintaining the surface finish and dimensional accuracy of the ring and preventing oxidation. It can also inhibit the diffusion of carbon elements from the surface of the bearing ring into the air, thereby reducing the thickness of the decarburized layer and improving the quality of the bearing ring. In addition, the thermal conductivity of argon is low, which can slow down the cooling rate of the bearing ring and make the bearing ring cool evenly in the furnace, which helps to reduce the temperature gradient inside the bearing ring, reduce residual stress, and improve the dimensional stability of the ring. The residual stress of the bearing ring can be reduced to the greatest extent through furnace cooling, because the temperature changes very slowly and the temperature gradient between the inside and outside of the ring is very small, which helps to make the internal structure of the bearing ring more uniform and further reduce the residual stress.

[0075] The above shows and describes the basic principles of the present invention. The above are only preferred embodiments of the present invention and are not intended to limit the present invention. The above embodiments and descriptions in the specification are only intended to illustrate the principles of the present invention. Without departing from the scope of the present invention, any modifications, equivalent substitutions and improvements made within the spirit and scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A bearing ring heat treatment process based on residual stress optimization, characterized in that The steps include: S1. Clean the surface of the bearing ring and ensure that it is clean and free of oil and impurities; S2, performing a segmented heat treatment on the bearing ring, heating the bearing ring to a predetermined heat treatment temperature; S3, quickly placing the heat-treated bearing ring into a quenching medium for rapid cooling; S4, tempering the quenched bearing ring; S5. Cooling the bearing ring after tempering.

2. A bearing ring heat treatment process based on residual stress optimization according to claim 1, characterized in that: In S1, the cleaning of the bearing ring surface is divided into three stages: the first stage is mechanical cleaning, the second stage is chemical cleaning, and the third stage is solvent cleaning; Mechanical cleaning includes sandblasting, where the sand blasting particle size is 50-70 mesh quartz sand, and the surface of the ferrule is fully covered by the sandblasting at a certain pressure and angle to ensure full coverage without damaging the surface of the ferrule; Chemical cleaning includes cleaning with a dilute hydrochloric acid solution. During the pickling process, the temperature of the dilute hydrochloric acid solution is between 20-60°C and the pickling time is 10 to 30 minutes; Solvent cleaning includes alcohol cleaning, the alcohol cleaning temperature is 20-45°C, and the cleaning time is 10 to 20 minutes.

3. A bearing ring heat treatment process based on residual stress optimization according to claim 2, characterized in that: In S2, the bearing ring is subjected to a segmented heating treatment including primary heating, secondary heating and tertiary heating; wherein The primary heating includes placing the bearing ring in a heating furnace and heating it to 80-100°C, and keeping the bearing ring warm for 1-1.5 minutes per millimeter of thickness; Secondary heating includes heating the bearing ring to 300-320°C and keeping it warm for 1-1.5 minutes per millimeter of thickness; The three heating steps include heating the bearing ring to 820-860°C and keeping the temperature for 1-1.5 minutes per millimeter of thickness.

4. The bearing ring heat treatment process based on residual stress optimization according to claim 3 is characterized in that: In S3, the bearing ring is quenched and cooled in a salt bath. The bearing ring is quickly taken out of the heating furnace after the holding time is reached and placed vertically in a quenching salt bath tank. The bearing ring is kept stable when entering the water to avoid collision between the bearing ring and the tank wall or excessive splashes. The temperature of the salt bath is controlled at 180-220°C and the cooling time is 5 to 15 minutes.

5. The bearing ring heat treatment process based on residual stress optimization according to claim 4 is characterized in that: The temperature of the bearing ring after quenching is 20-40℃.

6. The bearing ring heat treatment process based on residual stress optimization according to claim 5 is characterized in that: In S4, the bearing ring is subjected to tempering treatment including primary tempering and secondary tempering; The first tempering includes placing the bearing ring in a tempering furnace for tempering heating. The first tempering temperature is 150-170℃ and the holding time is 3-4 hours. The secondary tempering includes placing the bearing ring in a tempering furnace for secondary tempering heating. The secondary tempering temperature is 180-210°C and the insulation time is 3 to 4 hours.

7. The bearing ring heat treatment process based on residual stress optimization according to claim 1 is characterized in that: In S5, the bearing ring after the tempering treatment is cooled by furnace cooling.

8. The bearing ring heat treatment process based on residual stress optimization according to claim 7 is characterized in that: Argon gas is introduced into the tempering furnace during the cooling process of the bearing ring.

9. The bearing ring heat treatment process based on residual stress optimization according to claim 7 is characterized in that: There is a spacing distance between each bearing ring in the tempering furnace, and the spacing distance is not less than 1cm.

10. The bearing ring heat treatment process based on residual stress optimization according to claim 7, characterized in that: A plurality of thermocouples are installed inside the tempering furnace, and the plurality of thermocouples are evenly installed at different positions inside the tempering furnace.

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