Extreme working condition high carbon steel bearing gradient marb composite microstructure construction forming manufacturing method

Abstract

The application provides a forming manufacturing method of a gradient Mabe composite phase structure of an extreme working condition high-carbon steel bearing, and relates to the technical field of bearing manufacturing. The method comprises the following steps: determining a target carbonitriding temperature according to a first target carbon potential of a workpiece to be processed, determining a target carbonitriding time according to a target carbonitriding depth, and performing carbonitriding on the rolled workpiece to be processed according to the target carbonitriding temperature and the target carbonitriding time; determining a target austenitizing temperature according to a second target carbon potential of a carbonitriding furnace, and placing the workpiece to be processed after the carbonitriding treatment into a high-temperature box-type furnace to perform austenitizing on the workpiece to be processed after the carbonitriding treatment according to the target austenitizing temperature; determining a target isothermal quenching temperature according to the second target carbon potential in the carbonitriding furnace, and immersing the workpiece to be processed after the austenitizing into a low-temperature salt bath furnace to perform isothermal quenching according to the target isothermal quenching temperature. The application can improve the wear resistance, strength and toughness of the bearing.

Description

Technical Field

[0001] This invention relates to the field of bearing manufacturing technology, and more specifically, to a method for manufacturing high-carbon steel bearings under extreme operating conditions by constructing and forming a gradient Marbe multiphase microstructure. Background Technology

[0002] Bearings, as key components for transmitting motion and bearing force in mechanical equipment, directly affect the performance and lifespan of the host machine. Bearings mainly consist of raceways, rolling elements, and cages, with raceways being the core component. Controlling the microstructure of bearing raceways through forming and manufacturing processes to obtain high-performance bearing raceways is of great significance. High-end equipment bearings typically operate under extreme conditions such as high temperature, high speed, and heavy load, requiring bearing raceways to possess high wear resistance, high strength, and high toughness simultaneously. How to obtain bearing raceways that are both wear-resistant and possess high strength and toughness is a critical problem that urgently needs to be solved for high-end equipment bearings to meet extreme service conditions. Currently, high-carbon steel bearings have been using traditional martensitic heat treatment processes, resulting in martensitic structures with high strength but low toughness, and the surface and core properties are consistent, failing to achieve a synergistic match between high wear resistance and impact resistance. Therefore, to meet the requirements of extreme service conditions in high-end equipment, there is an urgent need to develop forming and manufacturing methods that achieve both surface strength and internal toughness. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the prior art by providing a method for manufacturing high-carbon steel bearings under extreme operating conditions by constructing a gradient Mabe multiphase microstructure, so as to achieve a synergistic improvement in the bearing's wear resistance, strength, and toughness.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0005] In a first aspect, embodiments of this application provide a method for constructing and manufacturing a high-carbon steel bearing with a gradient Marbe multiphase microstructure under extreme operating conditions, comprising: rolling a workpiece to be processed according to a target size; determining a target carbonitriding temperature based on a first target carbon potential in the workpiece to be processed, determining a target carbonitriding time based on a target carbonitriding layer depth, and performing carbonitriding on the rolled workpiece to be processed according to the target carbonitriding temperature and the target carbonitriding time; determining a target austenitizing temperature based on a second target carbon potential in the carbonitriding furnace, and placing the carbonitrided workpiece to be processed into a box-type high-temperature furnace to austenitize the carbonitrided workpiece to be processed according to the target austenitizing temperature; determining a target isothermal quenching temperature based on the second target carbon potential in the carbonitriding furnace, and immersing the austenitized workpiece to be processed into a low-temperature salt bath furnace for isothermal quenching according to the target isothermal quenching temperature, thereby constructing and obtaining a high-carbon steel bearing with a gradient Marbe multiphase microstructure under extreme operating conditions.

[0006] In one embodiment, rolling the workpiece to be processed according to the target size includes: determining the target feed speed of the pressure roll corresponding to the workpiece to be processed based on the relationship between the inner diameter and outer diameter of the workpiece, the speed of the drive roll of the rolling mill, the radius of the drive roll, the friction angle between the roll and the workpiece, and the radius of the pressure roll and the feed speed of the pressure roll; determining the target rolling ratio corresponding to the workpiece to be processed based on the principle of constant rolling volume, the relationship between the inner diameter of the workpiece, the radius of the pressure roll, the radius of the drive roll and the rolling ratio; and rolling the workpiece to be processed according to the target size, the target feed speed and the target rolling ratio.

[0007] In one embodiment, after rolling the workpiece to be processed, the method further includes: inspecting the rolled workpiece to be processed according to the target size to determine whether the rolled workpiece to be processed meets the finished product requirements.

[0008] In one embodiment, determining the target carbonitriding temperature based on the first target carbon potential in the workpiece to be processed includes: determining the relationship between the pressure of carbon dioxide in the gas introduced into the carbonitriding furnace, the pressure of carbon monoxide, the carbonitriding temperature and the carbon activity in the carbonitriding furnace; and determining the target carbonitriding temperature corresponding to the first target carbon potential in the workpiece to be processed based on the relationship between the carbon potential in the workpiece, the carbon activity in the carbonitriding furnace and the carbonitriding temperature.

[0009] In one embodiment, determining the target carbonitriding time based on the target carbonitriding layer depth includes: determining the target carbonitriding time corresponding to the target carbonitriding layer depth based on the relationship between carbonitriding temperature, carbonitriding time and carbonitriding layer depth.

[0010] In one embodiment, determining the target austenitizing temperature based on the second target carbon potential in the carbonitriding furnace includes: determining the target austenitizing temperature corresponding to the second target carbon potential in the carbonitriding furnace based on the relationship between the initial austenitizing transformation temperature, the final austenite formation temperature, and the carbon potential and austenitizing temperature in the carbonitriding furnace.

[0011] In one embodiment, the relationship between the initial austenitizing transformation temperature, the final austenite formation temperature, the carbon potential in the carbonitriding furnace, and the austenitizing temperature is shown in the following formula:

[0012] T A =T AC3 +(K A -C P )T AC1

[0013] Among them, T AIndicates the austenitizing temperature; T AC1 Indicates the initial austenitizing transformation temperature; T AC3 Indicates the final temperature at which austenite forms; K A This represents the austenitizing temperature correction factor, with a value ranging from 0.25 to 0.28; C P This indicates the carbon potential within the carbonitriding furnace.

[0014] In one embodiment, determining the target isothermal quenching temperature based on the second target carbon potential in the carbonitriding furnace includes: determining the target isothermal quenching temperature corresponding to the second target carbon potential in the carbonitriding furnace based on the initial martensite transformation temperature, the outer diameter and inner diameter of the workpiece, and the relationship between the carbon potential in the carbonitriding furnace and the isothermal quenching temperature.

[0015] In one embodiment, the relationship between the initial martensitic transformation temperature, the outer diameter and inner diameter of the workpiece, the carbon potential in the carbonitriding furnace, and the isothermal quenching temperature is shown in the following formula:

[0016]

[0017] Among them, T B Indicates the isothermal quenching temperature; K B This represents the isothermal quenching temperature correction factor, with a value ranging from 0.05 to 0.1; C P The carbon potential in the carbonitriding furnace is represented by d; the inner diameter of the workpiece is represented by d; the outer diameter of the workpiece is represented by D; and T represents the carbon potential in the carbonitriding furnace. MS This indicates the initial martensite transformation temperature.

[0018] In one embodiment, after immersing the austenitized workpiece in a low-temperature salt bath furnace for isothermal quenching according to the target isothermal quenching temperature, the method further includes: placing the isothermally quenched workpiece into a high-temperature tempering furnace and tempering the isothermally quenched workpiece according to preset tempering parameters.

[0019] The beneficial effects of this application are: (1) By actively coordinating the movement of the drive roller / pressure roller, the dual-drive deformation controls the metal flow speed and deformation amount on the bearing rolling surface, thereby achieving ultra-fine grain deformation on the bearing rolling surface; (2) By introducing nitrogen-containing martensite and carbonitride compounds into the bearing ring surface through carbonitriding preheating treatment, the surface wear resistance is improved; the high concentration of carbonitride on the surface reduces the critical cooling rate of the steel, increases the content of residual austenite on the bearing ring surface, reduces the origin-type spalling on the bearing ring surface, and further enhances the surface wear resistance; the compressive stress introduced in the co-diffusion layer after carbonitriding can effectively improve the wear resistance and fatigue performance of the bearing ring; (3) Based on the surface carbon potential and nitrogen potential, the austenitization and isothermal quenching temperatures of the Marbe multiphase heat treatment are determined, thereby introducing different contents of bainite on the bearing surface and core (usually more in the core). Under the genetic effect of rolling deformation and carbonitriding heat treatment, a nano-sized Marbe multiphase gradient structure with wear resistance on the surface and high toughness in the core is finally constructed, thereby achieving a synergistic improvement in bearing wear resistance, strength and toughness. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic flowchart illustrating a method for constructing and manufacturing a gradient Mabe multiphase microstructure for a high-carbon steel bearing under extreme working conditions, provided in an embodiment of this application.

[0022] Figure 2 A schematic flowchart illustrating a method for constructing and manufacturing a gradient Mabe multiphase microstructure for a high-carbon steel bearing under extreme working conditions, provided in an embodiment of this application.

[0023] Figure 3 A schematic flowchart illustrating a method for constructing and manufacturing a gradient Mabe multiphase microstructure for a high-carbon steel bearing under extreme working conditions, provided in an embodiment of this application.

[0024] Figure 4 A schematic flowchart illustrating a method for constructing and manufacturing a gradient Mabe multiphase microstructure for a high-carbon steel bearing under extreme working conditions, provided in an embodiment of this application.

[0025] Figure 5 This application provides a schematic diagram of the bearing surface structure in a method for manufacturing a high-carbon steel bearing under extreme working conditions by constructing a gradient Mabe multiphase microstructure.

[0026] Figure 6A schematic diagram of the bearing core structure in a method for constructing and manufacturing a high-carbon steel bearing under extreme working conditions using gradient Mabe multiphase microstructure, provided in an embodiment of this application;

[0027] Figure 7 This is a schematic diagram illustrating the relationship between bearing hardness and distance from the surface in a method for manufacturing a high-carbon steel bearing under extreme working conditions using gradient Mabe multiphase microstructure, as provided in an embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0029] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0030] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0031] Furthermore, the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Additionally, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0033] Figure 1A schematic flowchart illustrating a method for constructing and manufacturing a gradient Mabe multiphase microstructure for a high-carbon steel bearing under extreme operating conditions, as provided in this application embodiment; Figure 1 As shown, the method includes:

[0034] Step 110: Roll the workpiece to be processed according to the target dimensions.

[0035] The target size is the final size of the workpiece to be rolled; in actual operation, the target size includes the target diameter and the target height.

[0036] The workpiece to be processed refers to the bearing ring. This is because, although a bearing is composed of the ring, rolling elements and cage, the ring is the core component of the bearing. Therefore, it is of great significance to control the microstructure of the bearing ring through forming and manufacturing to obtain high-performance bearing rings.

[0037] During ring rolling, the main motor drives the drive roller to rotate, and the friction between the drive roller and the blank pulls the blank in and applies continuous pressure. At the same time, the friction between the ring blank and the pressure roller drives the pressure roller to rotate. Driven by the feed system, the pressure roller moves radially at a certain feed speed, and the center distance between it and the drive roller gradually decreases until deformation is complete.

[0038] During the rolling process, it is necessary to control the feed speed of the pressure rolls and the pressing ratio; specifically, such as Figure 2 As shown, step 110 above may further include steps 210 to 230:

[0039] Step 210: Determine the target feed speed of the pressure roller corresponding to the workpiece based on the relationship between the inner diameter and outer diameter of the workpiece, the speed of the driving roller of the rolling mill, the radius of the driving roller, the friction angle between the roller and the workpiece, the radius of the pressure roller and the feed speed of the pressure roller.

[0040] The relationship between the inner diameter and outer diameter of the workpiece, the speed of the rolling mill's drive roll, the radius of the drive roll, the friction angle between the roll and the workpiece, the radius of the pressure roll, and the feed speed of the pressure roll is shown in the following formula (1):

[0041]

[0042] Where v represents the feed speed of the pressure roller; n represents the rotational speed of the drive roller; β represents the friction angle between the workpiece and the roller; R represents the outer diameter of the workpiece; r represents the inner diameter of the workpiece; R1 represents the radius of the drive roller; and R2 represents the radius of the pressure roller.

[0043] In actual operation, by substituting the inner diameter and outer diameter of the workpiece to be processed into the above formula (1), the target feed speed of the pressure roller corresponding to the workpiece to be processed can be obtained.

[0044] Step 220: Based on the principle of constant rolling volume, determine the target rolling ratio of the workpiece according to the relationship between the inner diameter of the workpiece, the radius of the pressure roller, the radius of the drive roller and the rolling ratio.

[0045] The relationship between the inner diameter of the workpiece, the radius of the pressure roller, the radius of the drive roller, and the rolling ratio is shown in the following formula (2):

[0046]

[0047] Where k represents the rolling ratio; k max R0 represents the maximum rolling ratio; R1 represents the inner diameter of the workpiece; R2 represents the radius of the drive roller; and R2 represents the radius of the pressure roller.

[0048] Step 230: Roll the workpiece to be processed according to the target size, target feed rate and target rolling ratio.

[0049] In actual operation, the mill is controlled by the above-mentioned target feed speed and target rolling ratio to roll the workpiece to be processed. When the diameter and height of the workpiece to be processed reach the target diameter and target height in the target dimensions, the pressure roll stops feeding and the rolling process ends.

[0050] In practice, before rolling the workpiece, a rolling pretreatment can be performed. Specifically, the surface of the workpiece can be cleaned, such as by washing and degreasing it, and then the pretreated workpiece can be placed into the rolling mill for rolling.

[0051] In practice, after rolling the workpiece, the rolled workpiece can be inspected to determine whether it meets the finished product requirements. Specifically, after rolling the workpiece, the methods also include:

[0052] The rolled workpiece is inspected according to the target dimensions to determine whether it meets the finished product requirements.

[0053] In practice, an error range can be set for the target size based on experience or by consulting literature. When the rolled workpiece is within this error range, it is determined that the rolled workpiece meets the finished product requirements; otherwise, it does not meet the finished product requirements.

[0054] Step 120: Determine the target carbonitriding temperature based on the first target carbon potential in the workpiece to be processed, determine the target carbonitriding time based on the target carbonitriding layer depth, and perform carbonitriding on the rolled workpiece based on the target carbonitriding temperature and target carbonitriding time.

[0055] The first target carbon potential in the workpiece to be processed is the carbon potential in the workpiece to be processed.

[0056] The target carbonitriding temperature can be determined based on the relationship between carbon activity and carbon potential in the workpiece; specifically, such as... Figure 3 As shown, step 120 above may further include steps 310 to 330:

[0057] Step 310: Determine the relationship between the pressure of carbon dioxide, the pressure of carbon monoxide, the carbonitriding temperature, and the carbon activity in the carbonitriding furnace.

[0058] The relationship between the pressure of carbon dioxide and carbon monoxide in the gas introduced into the carbonitriding furnace, the carbonitriding temperature, and the carbon activity in the carbonitriding furnace is shown in the following formula (3):

[0059]

[0060] Among them, a c Indicates carbon activity; K represents the equilibrium constant; P CO This indicates the pressure of carbon monoxide in the gas introduced into the carbonitriding furnace; The pressure of carbon dioxide in the gas introduced into the carbonitriding furnace is indicated by T; T represents the carbonitriding temperature.

[0061] Step 320: Based on the relationship between the carbon potential in the workpiece, the carbon activity in the carbonitriding furnace, and the carbonitriding temperature, determine the target carbonitriding temperature corresponding to the first target carbon potential in the workpiece to be processed.

[0062] The relationship between the carbon potential in the workpiece, the carbon activity in the carbonitriding furnace, and the carbonitriding temperature is shown in the following formula (4):

[0063]

[0064] Among them, a c [%C] represents carbon activity; T represents carbonitriding temperature; [%C] represents carbon potential in the workpiece.

[0065] The target carbonitriding time can be determined based on the relationship between carbonitriding temperature, carbonitriding time, and carbonitriding layer depth. Specifically, determining the target carbonitriding time based on the target carbonitriding layer depth includes:

[0066] Based on the relationship between carbonitriding temperature, carbonitriding time, and carbonitriding layer depth, the target carbonitriding time corresponding to the target carbonitriding layer depth is determined.

[0067] The relationship between carbonitriding temperature, carbonitriding time, and carbonitriding layer depth is shown in the following formula (5):

[0068]

[0069] Where d represents the depth of the carbonitriding layer; t represents the carbonitriding time; and T represents the carbonitriding temperature.

[0070] In practice, before carbonitriding the rolled workpiece, a carbonitriding pretreatment can be performed. Specifically, the surface of the rolled workpiece can be cleaned, such as by washing, degreasing, and removing rust. After placing the rolled workpiece into the carbonitriding furnace, the air inside the furnace should be vented as soon as possible to prevent oxidation of the workpiece.

[0071] Step 130: Determine the target austenitizing temperature based on the second target carbon potential in the carbonitriding furnace, and place the carbonitrided workpiece into a box-type high-temperature furnace to austenitize it according to the target austenitizing temperature.

[0072] Among them, the second target carbon potential in the carbonitriding furnace is the carbon potential in the carbonitriding furnace.

[0073] The target austenitizing temperature can be determined based on the initial austenitizing transformation temperature, the final austenite formation temperature, and the relationship between the carbon potential and the austenitizing temperature in the carbonitriding furnace. Specifically, the target austenitizing temperature is determined based on the second target carbon potential in the carbonitriding furnace, including:

[0074] Based on the relationship between the initial austenitizing transformation temperature, the final austenite formation temperature, and the carbon potential and austenitizing temperature in the carbonitriding furnace, the target austenitizing temperature corresponding to the second target carbon potential in the carbonitriding furnace is determined.

[0075] The relationship between the initial austenitizing transformation temperature, the final austenite formation temperature, the carbon potential in the carbonitriding furnace, and the austenitizing temperature is shown in the following formula (6):

[0076] T A =T AC3 +(K A -C P )T AC1 (6)

[0077] Among them, T A Indicates the austenitizing temperature; T AC1 Indicates the initial austenitizing transformation temperature; T AC3 Indicates the final temperature at which austenite forms; K A This represents the austenitizing temperature correction factor, with a value ranging from 0.25 to 0.28; C P This indicates the carbon potential within the carbonitriding furnace.

[0078] Step 140: Determine the target isothermal quenching temperature based on the second target carbon potential in the carbonitriding furnace. Immerse the austenitized workpiece to be processed into a low-temperature salt bath furnace for isothermal quenching according to the target isothermal quenching temperature, and construct a high-carbon steel bearing with a Marbe multiphase gradient structure under extreme working conditions.

[0079] The target isothermal quenching temperature can be determined based on the initial martensitic transformation temperature, the outer diameter and inner diameter of the workpiece, and the relationship between the carbon potential in the carbonitriding furnace and the isothermal quenching temperature. Specifically, determining the target isothermal quenching temperature based on the second target carbon potential in the carbonitriding furnace includes:

[0080] Based on the relationship between the initial martensitic transformation temperature, the outer diameter and inner diameter of the workpiece, the carbon potential in the carbonitriding furnace and the isothermal quenching temperature, the target isothermal quenching temperature corresponding to the second target carbon potential in the carbonitriding furnace is determined.

[0081] The relationship between the initial martensitic transformation temperature, the outer diameter and inner diameter of the workpiece, the carbon potential in the carbonitriding furnace, and the isothermal quenching temperature is shown in the following formula (7):

[0082]

[0083] Among them, T B Indicates the isothermal quenching temperature; K B This represents the isothermal quenching temperature correction factor, with a value ranging from 0.05 to 0.1; C P The carbon potential in the carbonitriding furnace is represented by d; the inner diameter of the workpiece is represented by d; the outer diameter of the workpiece is represented by D; and T represents the carbon potential in the carbonitriding furnace. MS This indicates the initial martensite transformation temperature.

[0084] In practice, before austenitizing the carbonitrided workpiece, a Marbe multiphase heat treatment pretreatment can be performed. Specifically, the carbonitrided workpiece can be preheated, for example, by placing it in an oven at a preheating temperature of 200-350℃ for 5-10 minutes to ensure uniform heating during the austenitizing process.

[0085] In practice, after rolling the workpiece, it can be tempered to reduce the brittleness of the steel, reduce or eliminate internal stress, prevent workpiece deformation or cracking, stabilize workpiece dimensions, and obtain the required mechanical properties. Specifically, after immersing the austenitized workpiece in a low-temperature salt bath furnace for isothermal quenching according to the target isothermal quenching temperature, the extreme working condition high-carbon steel bearing gradient Mabe multiphase microstructure construction manufacturing method provided in this application embodiment further includes:

[0086] The isothermal quenched workpiece is placed in a high-temperature tempering furnace and tempered according to the preset tempering parameters.

[0087] In practice, when the workpiece material is high-temperature bearing steel, it is tempered three times at a tempering temperature of 535℃~550℃; when the workpiece material is ordinary bearing steel, it is tempered for 2 hours at a tempering temperature of 150~160℃.

[0088] The method for constructing and manufacturing high-carbon steel bearings with gradient Marbe multiphase microstructure under extreme working conditions provided in this application includes the following steps: First, the workpiece to be processed is rolled according to the target dimensions. Second, the target carbonitriding temperature is determined based on the first target carbon potential in the workpiece, and the target carbonitriding time is determined based on the target carbonitriding layer depth. The rolled workpiece is then carbonitrided according to the target carbonitriding temperature and the target carbonitriding time. Third, the target austenitizing temperature is determined based on the second target carbon potential in the carbonitriding furnace. The carbonitrided workpiece is then placed in a box-type high-temperature furnace and austenitized according to the target austenitizing temperature. Finally, the target isothermal quenching temperature is determined based on the second target carbon potential in the carbonitriding furnace. The austenitized workpiece is then immersed in a low-temperature salt bath furnace for isothermal quenching according to the target isothermal quenching temperature, thereby constructing a high-carbon steel bearing with a gradient Marbe multiphase microstructure under extreme working conditions. Thus, (1) by actively coordinating the movement of the drive roller / pressure roller, the dual-drive deformation controls the metal flow rate and deformation amount on the bearing rolling surface, thereby achieving ultra-fine grain deformation on the bearing rolling surface; (2) by introducing nitrogen-containing martensite and carbonitride compounds into the bearing ring surface through carbonitriding preheating treatment, the surface wear resistance is improved; the high concentration of carbonitride on the surface reduces the critical cooling rate of the steel, increases the content of residual austenite on the bearing ring surface, reduces the origin-type spalling on the bearing ring surface, and further enhances the surface wear resistance; the compressive stress introduced in the co-diffusion layer after carbonitriding can effectively improve the wear resistance and fatigue performance of the bearing ring; (3) based on the surface carbon potential and nitrogen potential, the austenitization and isothermal quenching temperatures of the Marbe multiphase heat treatment are determined, thereby introducing different contents of bainite on the bearing surface and core (usually more in the core). Under the genetic effect of rolling deformation and carbonitriding heat treatment, a nano-sized Marbe multiphase gradient structure with wear resistance on the surface and high toughness in the core is finally constructed, thereby achieving a synergistic improvement in bearing wear resistance, strength and toughness.

[0089] After introducing the manufacturing method for gradient Mabe multiphase microstructure formation of high-carbon steel bearings under extreme operating conditions according to exemplary embodiments of this disclosure, the following will be discussed... Figure 4 The following is an illustration of an experimental example:

[0090] For a certain type of bearing (outer diameter 90mm, inner diameter 75mm) made of GCr15, the manufacturing method of its Mabe multiphase gradient structure construction is implemented according to the following steps:

[0091] Step 1: Controlled Strain Rolling Forming

[0092] After cleaning and degreasing the bearing ring blank, it is placed on a rolling mill for rolling. The drive roll speed is 146 r / min, the pressure roll feed speed is 1 mm / s, and the rolling ratio is 1.35. When the diameter and height of the workpiece reach the predetermined dimensions, the pressure roll stops feeding, and the rolling process ends. The workpiece diameter and height are then inspected to ensure they meet the finished product requirements.

[0093] Step 2: Carbonitriding preheating treatment

[0094] The workpiece surface is cleaned, degreased, and derusted. After loading the workpiece into the furnace, the air inside the furnace must be vented as soon as possible, with a venting time of 40 minutes. The workpiece undergoes a strong carbonitriding treatment, maintaining the furnace temperature at 850℃ for 150 minutes, with the carbon potential controlled at 1.3% and the ammonia flow rate at 1.5 NL / min. The workpiece then undergoes a diffusion treatment, continuing to maintain the furnace temperature at 850℃, with a diffusion time of 60 minutes (the carbonitriding time), a carbon potential of 1.0%, and an ammonia flow rate of 1.5 NL / min.

[0095] Step 3: Marbe multiphase heat treatment

[0096] The bearing races were preheated in an oven at 300℃ for 5 minutes. Then, they were placed in a box-type high-temperature furnace for austenitization at 850℃ for 22 minutes. After austenitization, the bearing races were immersed in a low-temperature salt bath furnace and isothermally quenched at 240℃ for 20 minutes. After quenching, the bearing races were quickly removed and placed in a large oil bath. Once salt crystallized on the surface of the bearing races, they were removed, rinsed in warm water, and air-dried. Finally, the bearing races were placed in a tempering furnace and tempered at 160℃ for 2 hours.

[0097] Microscopic observation of the bearing rings obtained in the above embodiments revealed that the bearing surface of the embodiments of the present invention (such as...) Figure 5 (as shown) and core (as shown) Figure 6 As shown, different amounts of bainite were introduced, with a higher bainite content in the core. Mechanical property tests on the bearing rings revealed that the hardness of the GCr15 bearing rings in this embodiment of the invention decreased progressively from the surface to the core (e.g., ...). Figure 7(As shown); the wear rate is reduced by 52% compared to the traditional heat-treated bearing rings; the impact energy of the traditionally manufactured bearing rings is 17 J / cm², and the impact strength is 62 J / cm², resulting in a synergistic improvement in the wear resistance and impact toughness of the bearing rings. This demonstrates that the Marbe multiphase gradient structure constructed using the extreme-condition high-carbon steel bearing gradient Marbe multiphase structure construction method provided in this application can achieve high wear resistance / high strength and toughness in bearings, meeting the service requirements of bearings under extreme conditions.

[0098] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A manufacturing method of a gradient M-Abe multi-phase structure of an extreme working condition high carbon steel bearing, characterized in that, The method comprises the following steps: rolling a workpiece according to a target size; determining a target carbonitriding temperature according to a first target carbon potential in the workpiece, determining a target carbonitriding time according to a target carbonitriding layer depth, and carbonitriding the rolled workpiece according to the target carbonitriding temperature and the target carbonitriding time; determining a target austenitizing temperature according to a second target carbon potential in a carbonitriding furnace, and austenitizing the carbonitriding workpiece in a box-type high-temperature furnace according to the target austenitizing temperature; determining a target isothermal quenching temperature according to the second target carbon potential in the carbonitriding furnace, and isothermal quenching the austenitized workpiece in a low-temperature salt bath furnace according to the target isothermal quenching temperature, thereby obtaining an extreme working condition high-carbon steel bearing with a marbain complex gradient structure; the determination of the target isothermal quenching temperature according to the second target carbon potential in the carbonitriding furnace comprises: determining the target isothermal quenching temperature corresponding to the second target carbon potential in the carbonitriding furnace according to a relationship between a martensite initial transformation temperature, an outer diameter and an inner diameter of the workpiece, and a carbon potential in the carbonitriding furnace and the isothermal quenching temperature; the relationship between the martensite initial transformation temperature, the outer diameter and the inner diameter of the workpiece, the carbon potential in the carbonitriding furnace and the isothermal quenching temperature is shown in the following formula: ； wherein, represents the isothermal quenching temperature; represents the isothermal quenching temperature correction coefficient, and the value range is 0.05~0.1; represents the carbon potential in the carbonitriding furnace; represents the inner diameter of the workpiece; represents the outer diameter of the workpiece; represents the martensite initial transformation temperature; after the austenitized workpiece is immersed in the low-temperature salt bath furnace according to the target isothermal quenching temperature, the method further comprises: putting the isothermal quenched workpiece into a high-temperature tempering furnace, and tempering the isothermal quenched workpiece according to preset tempering parameters.

2. The method of claim 1, wherein, the rolling of the workpiece according to the target size comprises: determining a target feed speed of a pressure roller corresponding to the workpiece according to a relationship between an inner diameter and an outer diameter of the workpiece, a driving roller rotation speed of a rolling mill, a driving roller radius, a friction angle between a rolling roller and the workpiece, a pressure roller radius and a pressure roller feed speed; determining a target rolling ratio corresponding to the workpiece according to a relationship between the inner diameter of the workpiece, the pressure roller radius, the driving roller radius and a rolling ratio based on a rolling volume invariable principle; rolling the workpiece according to the target size, the target feed speed and the target rolling ratio.

3. The method of claim 2, wherein, after the rolling of the workpiece, the method further comprises: inspecting the rolled workpiece according to the target size to determine whether the rolled workpiece meets product requirements.

4. The method of claim 1, wherein, the determination of the target carbonitriding temperature according to the first target carbon potential in the workpiece comprises: determining a relationship between a pressure of carbon dioxide, a pressure of carbon monoxide, a carbonitriding temperature and a carbon activity in the carbonitriding furnace; determining the target carbonitriding temperature corresponding to the first target carbon potential in the workpiece according to a relationship between a carbon potential in the workpiece, the carbon activity in the carbonitriding furnace and the carbonitriding temperature.

5. The method of claim 1, wherein, The target carbonitriding time is determined according to the target carbonitriding layer depth, and the target carbonitriding layer depth is determined according to the target carbonitriding temperature and the target carbonitriding time. The target carbonitriding time corresponding to the target carbonitriding layer depth is determined according to the relationship among the carbonitriding temperature, the carbonitriding time and the carbonitriding layer depth.

6. The method of claim 1, wherein, The target austenitizing temperature is determined according to the second target carbon potential in the carbonitriding furnace. The target austenitizing temperature corresponding to the second target carbon potential in the carbonitriding furnace is determined according to the relationship among the austenitizing initial transformation temperature, the austenite formation final temperature, the carbon potential in the carbonitriding furnace and the austenitizing temperature.

7. The method of claim 6, wherein, The relationship among the austenitizing initial transformation temperature, the austenite formation final temperature, the carbon potential in the carbonitriding furnace and the austenitizing temperature is shown in the following formula: ； wherein, represents an austenitizing temperature; represents an austenitizing initial transformation temperature; represents an austenite formation final temperature; represents an austenitizing temperature correction factor, and has a value range of 0.25~0.28; represents a carbon potential in a carbonitriding furnace.

Images