A method for preparing a high-strength wear-resistant bearing

Abstract

The present invention relates to the field of alloy steel materials, and in particular to a method for preparing a high-strength wear-resistant bearing. A controllable medium composite tissue processing step is added to the process, and a metal material modification technology in a controllable medium environment is used to form a composite tissue in a product matrix. The composite tissue is distributed in a gradient manner to make the core of the product high in strength and impact resistance, and the surface hardness and wear resistance are high, so that a service life of 500 hours under low-speed and heavy-load service conditions and a friction coefficient of less than 0.05 in the entire life cycle can be achieved. The 500-hour service life under the service conditions greatly reduces the replacement frequency of the shaft sleeve and the equipment production downtime loss. The friction coefficient of less than 0.05 in the entire life cycle greatly improves the wear degree of the friction pair of the shaft hole matching, alleviates the sliding friction strength, and serves the purpose of extending the service life of the shaft sleeve itself and the shaft body matched therewith.

Description

Technical Field

[0001] The invention relates to the field of alloy steel materials, and in particular to a method for preparing a high-strength wear-resistant bearing. Background Art

[0002] Bearings are an indispensable and important component in modern mechanical equipment. Their main function is to support mechanical rotating bodies, reduce the friction coefficient during their movement, and ensure rotation accuracy. During use, bearings are prone to surface wear and dimensional changes due to the need to withstand long-term periodic loads, poor lubrication, or harsh working environments, which affects the service life of bearings and increases equipment maintenance costs. Therefore, it is necessary to improve the strength and wear resistance of bearings to increase the service life of bearings.

[0003] Existing products generally use conventional heat treatment processes. The Chinese invention patent with the authorization announcement number CN113430462B discloses a high-strength, corrosion-resistant low-carbon alloy steel and its preparation method. By regulating the chemical element composition and mass percentage of the raw materials and strictly controlling the quenching, tempering and cooling methods, the strength and corrosion resistance of the low-carbon alloy steel are improved. However, the heat treatment process is still prone to large fluctuations in the hardness of the product matrix, uneven surface hardness, and soft spots, resulting in the product being not wear-resistant and having a short life, and also affecting the service life of the shaft body that cooperates with it. Summary of the invention

[0004] Technical purpose: In order to overcome the deficiencies in the prior art, the present invention provides a method for preparing a high-strength wear-resistant bearing, so as to achieve a product with high core strength and impact resistance, high surface hardness and wear resistance.

[0005] Technical solution: To achieve the above purpose, the present invention discloses a method for preparing a high-strength wear-resistant bearing, comprising the following steps:

[0006] S1: Raw material blanking, designing products of different specifications according to the shape and structure of the sliding bearing, and cutting or forging according to the length of the product to form a blank, wherein the raw material is low-carbon alloy steel;

[0007] S2: Pre-fire processing, pre-processing the blank, adjusting the shape of the blank according to the size of the sliding bearing, and processing all dimensions except the outer circle and the inner hole to the finished product state. The outer circle and the inner hole dimensions are processed to the semi-finished product state in this process;

[0008] S3: heat treatment, the product obtained in step S2 is quenched at 850-950°C and tempered at 650-950°C to obtain 100% S structure on the surface, with a grain size of ≥ grade 5;

[0009] S4: Finishing: According to the design requirements of the sliding bearing, the outer circle and inner hole dimensions are finely ground to the finished product size to obtain the initial bearing;

[0010] S5: Controllable medium composite tissue processing, the controllable medium includes a gas medium and a liquid medium, the gas medium includes CO, H2 and N2, and the liquid medium includes K2CO3, Na2CO3, NaCNO, Pr and Nd.

[0011] Furthermore, the percentage of the gas medium is: CO 15-20%, H2 40-45%, N2 35-45%; the percentage of the liquid medium is: K2CO3 30%-40%, Na2CO3 42%-50%, NaCNO 17%-28%, trace amount of Pr, trace amount of Nd.

[0012] Furthermore, the percentage of the gas medium is: CO 18%, H2 42%, N2 40%; the percentage of the liquid medium is: K2CO3 32%, Na2CO3 48%, NaCNO 19%, trace amount of Pr, trace amount of Nd.

[0013] Furthermore, the controllable medium composite tissue processing comprises the following steps:

[0014] S51: gas medium treatment, placing the initial bearing in the gas medium, controlling the temperature at 800-900° C., and maintaining it for 10-20 hours;

[0015] S52: liquid medium treatment, placing the initial bearing after gas medium treatment in the liquid medium, controlling the temperature at 500-600° C., and maintaining it for 2-4 hours;

[0016] The obtained high-strength wear-resistant bearing composite structure composition is: S+C+Fe2N+Fe3N+Fe4N.

[0017] Furthermore, in the step S51, the temperature is 830-850°C and maintained for 15 hours; in the step S52, the temperature is 545-560°C and maintained for 3 hours.

[0018] Furthermore, the low carbon alloy steel includes the following components in percentage by mass: C 0.17-0.23%, Si 0.15-0.37%, Mn 0.55-0.95%, S≤0.035%, P≤0.035, Cr 0.30-0.70%, Ni 0.45-0.80%, Cu≤0.03%, Mo 0.15-0.30%, Ti 0.04-0.10%, and the rest is Fe and unavoidable impurities.

[0019] The method for preparing the high-strength wear-resistant bearing of the present invention has at least the following technical effects:

[0020] The present invention adds a controllable medium composite tissue processing step in the process, and forms a composite tissue in the product matrix through the metal material modification technology in the controllable medium environment. The composite tissue is distributed in a gradient manner to make the core of the product high in strength and impact resistance, and the surface hardness is high and wear-resistant, so as to achieve a service life of 500 hours under the low-speed and heavy-load bench test conditions of GB / T23894 and a friction coefficient of less than 0.05 in the entire life cycle. The 500-hour service life under the bench test conditions greatly reduces the replacement frequency of the bushing and the equipment production downtime loss. The friction coefficient of less than 0.05 in the entire life cycle greatly improves the wear degree of the friction pair of the shaft hole matching, alleviates the sliding friction strength, and serves the purpose of extending the service life of both the bushing itself and the shaft body matched therewith. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a microstructure photo of a high-strength wear-resistant bearing after 500 times magnification;

[0022] Figure 2 This is a comparison chart of the friction coefficient of high-strength wear-resistant bearings with different process solutions. DETAILED DESCRIPTION

[0023] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0024] Example 1: A method for preparing a high-strength wear-resistant bearing, the raw material is low-carbon alloy steel, the low-carbon alloy steel includes the following components in percentage by mass: C 0.20%, Si 0.3%, Mn 0.70%, S 0.030%, P 0.030%, Cr 0.50%, Ni 0.55%, Cu 0.02%, Mo 0.20%, Ti 0.07%, and the rest is Fe and unavoidable impurities. The wear-resistant bearing is prepared according to the following steps:

[0025] S1: Raw material blanking: according to the shape and structure of the sliding bearing, design the raw materials of products with different specifications, and cut or forge them according to the length of the product to form blanks;

[0026] S2: Pre-fire processing, pre-processing the blank, adjusting the shape of the blank according to the size of the sliding bearing, and processing all dimensions except the outer circle and the inner hole to the finished product state. The outer circle and the inner hole dimensions are processed to the semi-finished product state in this process;

[0027] S3: heat treatment, the product obtained in step S2 is quenched at 850-950°C and tempered at 650-950°C to obtain 100% S structure on the surface, with a grain size of ≥5;

[0028] S4: Finishing: According to the design requirements of the sliding bearing, the outer circle and inner hole dimensions are finely ground to the finished product size to obtain the initial bearing.

[0029] Example 2-Example 5: Referring to the low carbon alloy steel composition and heat treatment method in Example 1, the obtained initial bearing is treated as follows:

[0030] S5: Controllable medium composite tissue processing, the controllable medium includes gas medium and liquid medium, the gas medium includes CO, H2 and N2, and the liquid medium includes K2CO3, Na2CO3, NaCNO, trace amount of Pr and trace amount of Nd. Each gas medium and liquid medium is adjusted, and multiple embodiments are carried out. The specific parameters of each embodiment are shown in Table 1.

[0031] Table 1: Test parameters of Example 2-Example 5

[0032]

[0033] According to the parameters in each embodiment, the initial bearing is processed as follows:

[0034] S51: Gas medium treatment, placing the initial bearing in a gas medium, controlling the temperature at 850°C, and maintaining it for 15 hours;

[0035] S52: Liquid medium treatment, placing the initial bearing after gas medium treatment in the liquid medium, controlling the temperature at 560° C., and maintaining it for 3 hours.

[0036] The final product performance test results obtained from Example 1 to Example 5 are shown in Table 2. Figure 2 A comparison chart of the friction coefficient of high-strength wear-resistant bearings of different process schemes in Examples 1 to 5 is also provided.

[0037] Table 2: Test results of Example 1-Example 5

[0038]

[0039] Example 6: Referring to the parameters of Example 5, the temperature and time of the controllable medium treatment are adjusted as follows:

[0040] S51: gas medium treatment, placing the initial bearing in a gas medium, controlling the temperature at 800°C, and maintaining it for 20 hours;

[0041] S52: Liquid medium treatment, placing the initial bearing after gas medium treatment in the liquid medium, controlling the temperature at 500° C., and maintaining it for 4 hours.

[0042] Example 7: Referring to the parameters of Example 5, the temperature and time of the controllable medium treatment are adjusted as follows:

[0043] S51: gas medium treatment, placing the initial bearing in a gas medium, controlling the temperature at 900°C, and maintaining it for 10 hours;

[0044] S52: Liquid medium treatment, placing the initial bearing after gas medium treatment in the liquid medium, controlling the temperature at 600° C., and maintaining it for 2 hours.

[0045] Example 8: Referring to the parameters of Example 5, the temperature and time of the controllable medium treatment are adjusted as follows:

[0046] S51: gas medium treatment, placing the initial bearing in a gas medium, controlling the temperature at 830°C, and maintaining it for 10 hours;

[0047] S52: Liquid medium treatment, placing the initial bearing after gas medium treatment in the liquid medium, controlling the temperature at 545° C., and maintaining it for 2 hours.

[0048] The performance test results of the final products obtained from Examples 6 to 8 are shown in Table 3:

[0049] Table 3: Test results of Example 6-Example 8

[0050]

[0051] Example 9: Referring to the parameters of Example 5, the mass percentage of each component of low-carbon alloy steel is adjusted as follows:

[0052] C 0.17%, Si 0.15%, Mn 0.55%, S 0.030%, P 0.030%, Cr 0.30%, Ni 0.45%, Cu 0.02%, Mo 0.15%, Ti 0.04%, and the rest are Fe and inevitable impurities.

[0053] Example 10: Referring to the parameters of Example 5, the mass percentage of each component of low-carbon alloy steel is adjusted as follows:

[0054] C 0.23%, Si 0.37%, Mn 0.95%, S 0.035%, P 0.035%, Cr 0.70%, Ni 0.80%, Cu 0.03%, Mo 0.30%, Ti 0.10%, and the rest are Fe and inevitable impurities.

[0055] The performance test results of the final products obtained in Example 9 and Example 10 are shown in Table 4:

[0056] Table 4: Test results of Example 9-Example 10

[0057]

[0058] By comparing the test results of Example 1 with those of Example 2-Example 10, it can be seen that by subjecting the initial bearing to a controllable medium composite structure treatment and controlling the component system and treatment process of each gas medium and liquid medium during the treatment process, a bearing product with high strength and high wear resistance can be finally obtained. Through the metal material modification technology in a controllable medium environment, the product matrix forms a composite structure, and the composition of the composite structure is: S+C+Fe2N+Fe3N+Fe4N+nanomolecules. Figure 1 The figure shows a 500-fold magnified microstructure photograph of the high-strength wear-resistant bearing obtained in Example 5 of the present invention. The composite structure has a high core strength and impact resistance, a high surface hardness and wear resistance through a gradient distribution, and can achieve a service life of 500 hours under low-speed and heavy-load bench test conditions and a friction coefficient of less than 0.05 during the entire life cycle.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-strength wear-resistant bearing, characterized in that: The steps include: S1: Raw material blanking, designing products of different specifications according to the shape and structure of the sliding bearing, and cutting or forging the products according to their length to form blanks, wherein the raw material is low-carbon alloy steel; S2: Pre-fire processing, pre-processing the blank, adjusting the shape of the blank according to the size of the sliding bearing, processing all dimensions except the outer circle and the inner hole to the finished product state, and the outer circle and the inner hole dimensions are processed to the semi-finished product state in this process; S3: heat treatment, the product obtained in step S2 is quenched at 850-950°C and tempered at 650-950°C to obtain 100% S structure on the surface, with a grain size of ≥ grade 5; S4: Finishing: According to the design requirements of the sliding bearing, the outer circle and inner hole dimensions are finely ground to the finished product size to obtain the initial bearing; S5: Controllable medium composite tissue processing, the controllable medium includes a gas medium and a liquid medium, the gas medium includes CO, H2 and N2, and the liquid medium includes K2CO3, Na2CO3, NaCNO, Pr and Nd.

2. The method for preparing a high-strength wear-resistant bearing according to claim 1, characterized in that: The percentage of the gas medium is: CO 15-20%, H2 40-45%, N2 35-45%; the percentage of the liquid medium is: K2CO3 30%-40%, Na2CO3 42%-50%, NaCNO 17%-28%, trace amount of Pr, trace amount of Nd.

3. The method for preparing a high-strength wear-resistant bearing according to claim 2, characterized in that: The percentage of the gas medium is: CO 18%, H2 42%, N2 40%; the percentage of the liquid medium is: K2CO3 32%, Na2CO3 48%, NaCNO19%, trace amount of Pr, trace amount of Nd.

4. A method for preparing a high-strength wear-resistant bearing according to claim 2 or 3, characterized in that: The controllable medium composite tissue processing comprises the following steps: S51: gas medium treatment, placing the initial bearing in the gas medium, controlling the temperature at 800-900° C., and maintaining it for 10-20 hours; S52: liquid medium treatment, placing the initial bearing after gas medium treatment in the liquid medium, controlling the temperature at 500-600° C., and maintaining it for 2-4 hours; The obtained high-strength wear-resistant bearing composite structure composition is: S+C+Fe2N+Fe3N+Fe4N.

5. The method for preparing a high-strength wear-resistant bearing according to claim 4, characterized in that: In the step S51, the temperature is 830-850°C and maintained for 15 hours; in the step S52, the temperature is 545-560°C and maintained for 3 hours.

6. The method for preparing a high-strength wear-resistant bearing according to claim 1, characterized in that: The low carbon alloy steel comprises the following components in percentage by mass: C 0.17-0.23%, Si 0.15-0.37%, Mn 0.55-0.95%, S≤0.035%, P≤0.035, Cr 0.30-0.70%, Ni 0.45-0.80%, Cu≤0.03%, Mo 0.15-0.30%, Ti 0.04-0.10%, and the rest are Fe and unavoidable impurities.

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