A metal steel ring in a steel belt assembly for continuously variable transmissions and its preparation method

Abstract

This invention discloses a metal steel ring for a continuously variable transmission (CVT) steel belt assembly and its preparation method. The metal steel ring is made of a strip-shaped general-purpose 18Ni series martensitic aging steel with laser-textured patterns on both sides, welded into a ring shape. Then, CoCrFeNiAl is deposited on the inner and outer walls of the ring by magnetron sputtering. X Ta Y )N Z It is made of high-entropy alloy film; the present invention uses general 18Ni martensitic aging steel instead of special martensitic aging steel, and the raw materials are easy to obtain; the fatigue strength of the metal steel ring prepared by the present invention is increased by more than 30%, and the wear depth is reduced by more than 70% under the same pin-disc wear test conditions.

Description

Technical Field

[0001] This invention relates to a metal steel ring in a steel belt assembly for continuously variable transmissions and its preparation method. Background Technology

[0002] Continuously variable transmissions (CVTs) offer advantages such as smooth operation, absence of sudden acceleration abruptness, and light weight, but also present manufacturing challenges. The steel belt assembly is one of the core components of a CVT, consisting of push plates and metal rings placed on either side. These metal rings are made of a certain number of stacked annular thin steel sheets, the number varying depending on the model, typically 6, 10, or 12. The quality of the steel rings affects not only the transmitted torque but also their service life. During CVT operation, the metal rings are subjected to alternating stress and wear with the push plates; therefore, the main failure modes of the metal rings are fatigue fracture and wear. Consequently, improving their wear resistance and fatigue strength has always been a research focus. Summary of the Invention

[0003] To overcome the problems of insufficient wear resistance and easy fatigue failure between the metal steel ring and the push plate in the steel belt assembly for continuously variable transmissions (CVTs), the present invention provides a metal steel ring in the steel belt assembly for CVTs and its preparation method.

[0004] The technical solution of the present invention is as follows:

[0005] A metal steel ring in a continuously variable transmission (CVT) steel belt assembly is made of strip-shaped, double-sided laser-textured general-purpose 18Ni series martensitic aging steel welded into a ring shape, and then deposited on the inner and outer walls of the ring by magnetron sputtering (CoCrFeNiAl). X Ta Y )N Z Made of high-entropy alloy thin film;

[0006] The specific composition by mass percentage of general-purpose 18Ni series martensitic aging steel is as follows: nickel 16-19%, cobalt 10-13%, molybdenum 4-6%, titanium 1-2%, aluminum <0.2%, carbon <0.02%, silicon <0.01%, sulfur <0.001%, phosphorus <0.001%, and the balance is iron;

[0007] Laser-textured patterns include geometric patterns such as grooves, circles, or rhombuses.

[0008] (CoCrFeNiAl X Ta Y )N Z The thickness of the high-entropy alloy thin film is 4-6 μm, (CoCrFeNiAl) X Ta Y )N ZIn this context, X, Y, and Z represent atomic ratios, where X = 0.3-0.9, Y = 0.4-0.8, and Z = 0.3-0.5. Co, Cr, Fe, and Ni have an equal atomic ratio of 1.

[0009] (CoCrFeNiAl X Ta Y )N Z In high-entropy alloy thin films, the atomic ratios of Al, Ta, and N are X = 0.3-0.9, Y = 0.4-0.8, and Z = 0.3-0.5, respectively. If X < 0.3, the film has low hardness and poor wear resistance, resulting in poor wear resistance of the prepared metal steel ring. If X > 0.9, the film has poor ductility and toughness, resulting in poor fatigue strength of the prepared metal steel ring. If Y < 0.4, no phase transformation occurs, leading to low film hardness. If Y > 0.8, the film is prone to brittleness and cracking. If Z < 0.3, the amount of metal nitride phase in the film is small, and its effect on improving film hardness and wear resistance is not significant. If Z > 0.5, the amount of metal nitride phase in the film increases rapidly, causing columnar coarse grains and pores, which lead to cracking, reduce film hardness and elastic modulus, and worsen the wear resistance of the metal steel ring.

[0010] The method for preparing the metal steel ring in the continuously variable transmission (CVT) steel belt assembly of the present invention includes the following steps:

[0011] (1) Using laser to prepare textured patterns on two surfaces of strip-shaped general-purpose 18Ni series martensitic aging steel;

[0012] (2) Weld the strip-shaped general-purpose 18Ni series martensitic aging steel treated in step (1) into a metal steel ring;

[0013] (3) Deposit (CoCrFeNiAl) on the inner and outer walls of the metal ring obtained in step (2) by magnetron sputtering. X Ta Y )N Z High-entropy alloy thin films.

[0014] Furthermore, the operation method of step (1) is as follows:

[0015] Using silicon carbide sandpaper, the surface of the strip-shaped general-purpose 18Ni series martensitic aging steel was polished in the order of 320#, 600#, 1000#, 1500#, and 2000#. After polishing, the surface was ultrasonically vibrated in acetone for 15 minutes to remove impurities. Then, it was ultrasonically vibrated in anhydrous ethanol for 15 minutes to remove residual acetone solution. Finally, it was removed and dried. The pretreated strip-shaped general-purpose 18Ni series martensitic aging steel was fixed on the laser processing platform, and the laser was turned on. Switch on the laser and input the laser process parameters: laser power 60-80W, scanning speed 5-20mm / s, spot diameter 10-30μm, pulse width 0.2-0.6ms, pulse frequency 15-30Hz, and number of scans 2-4. Process textured patterns on both surfaces of the steel, with texture dimensions of 10-40μm width, 5-20μm depth, 100-300μm spacing between textures, and texture coverage of 20-40% of the area. After processing, remove the steel and turn off the laser switch.

[0016] The purpose of using laser to prepare different textures in this invention is: (1) to improve the bonding force between the substrate and the film; and (2) to increase the wear resistance of the metal steel ring. In this invention, the area ratio of different textures is 20-40%, where the area ratio refers to the proportion of the texture area in the total area of ​​the substrate. If the texture area ratio is less than 20%, the lubricant storage capacity will be small, and the improvement in wear resistance will not be significant. If the texture area ratio is greater than 40%, the excessively small pit spacing will cause the surface roughness of the friction pair to increase rapidly, thereby affecting the wear resistance of the metal steel ring.

[0017] Furthermore, the welding in step (2) can be performed using welding methods such as laser welding or argon arc welding. The specific operation method is as follows:

[0018] The strip-shaped general-purpose 18Ni series martensitic aging steel with textured morphology was placed in acetone and ultrasonically vibrated for 15 minutes to remove the surface oxides. Then, it was placed in anhydrous ethanol and ultrasonically vibrated for 15 minutes to remove the residual acetone solution. Finally, it was taken out and dried. The welding equipment was turned on, and the pretreated steel was placed on the welding fixture. After the steel was rounded, it was welded close to the rolled edge. The welding parameters were set as follows: welding power 180-200W, welding speed 4-8mm / s, and welding spot 0.5-1.2mm. After welding, the equipment was turned off and the metal steel ring was removed.

[0019] Furthermore, the magnetron sputtering equipment in step (3) includes: a cavity, a frame, a substrate heating rotary stage, a magnetron target, a vacuum pumping system, a cooling water unit, and a computer control platform; wherein, the cavity is installed on the frame and connected to the vacuum pumping system located inside the frame, multiple magnetron targets and magnetron target baffles are evenly distributed on the inner wall of the cavity, and multiple gas channels are distributed on the outer wall of the cavity; the substrate heating rotary stage is installed inside the cavity, and the rotary stage is divided into two parts: a sample stage and a rotating disk; the sample stage includes rollers, a rotary motor, a rotating shaft, an adjustable connecting rod, and a sample stage base, the bottom end of the connecting rod is connected to the rotating disk, and the top end is connected to the sample stage base, and the position, direction, and angle of the sample stage can be adjusted by adjusting the curvature of the connecting rod; the sample stage base has two circular holes for connecting the rotating shaft, and the rotating shaft is connected to the rotary motor and The rollers and rotary motor are equipped with heat insulation boxes. Heating devices are installed inside the rollers. The sample is placed on two rollers, and the rotary motor drives the rollers to rotate, causing the sample to rotate. The working principle of the spin disk is as follows: the output end of the spin motor is connected to a small gear meshing with a spin gear inside the machine. A spin shaft is installed on the spin gear, and the top of the spin shaft is connected to the spin disk, thus driving the spin disk to rotate via gear transmission. Multiple mounting positions for sample stage connecting rods are arranged in a circular array on the spin disk. The vacuum pumping system includes a mechanical pump and a molecular pump. The cooling water unit has inlets and outlets for the molecular pump, the magnetron target, and the magnetron target, primarily for cooling the magnetron target and the molecular pump. The computer control platform controls the heating devices and the rotation of the spin disk in the substrate heating spin stage.

[0020] Specifically, CoCrFeNiAl is deposited on the inner and outer walls of the metal ring. X Ta Y )N Z The method for producing high-entropy alloy thin films is as follows:

[0021] The textured metal ring was ultrasonically cleaned in anhydrous ethanol for 15 minutes to remove residual impurities, and then dried with a blower. The CoCrFeNi high-entropy alloy target, Ta target, and Al target were placed on the magnetron target. The cleaned metal ring was then mounted on the two rollers of the sample stage. The angle of the connecting rod was adjusted and fixed to ensure the metal ring was perpendicular to the magnetron target, allowing the sputtered atoms from the target to deposit onto the inner and outer surfaces of the metal ring. After sample loading, the chamber door and vent valve were closed. The mechanical pump and evacuation valve were turned on, and the vacuum was evacuated to below 8.0 Pa. The evacuation valve was then closed. The cooling water unit was turned on, and the molecular pump and gate valve were turned on, evacuating to a vacuum of 3.0 × 10⁻⁶ Pa. -3Below Pa; adjust the gas pressure to between 0.8-1 Pa using a gate valve; turn on the heating switch, rotation switch, and rotary switch on the computer control platform, setting the substrate temperature to 400-600℃, the rotational disk speed to 10-20 r / min, and the roller speed to 5-10 r / min; turn on the argon valve, setting the argon flow rate to 10-30 sccm; turn on the bias switch, setting the bias voltage to 80-120V; sequentially perform ignition on the CoCrFeNi alloy target, Al target, and Ta target. After successful ignition, adjust the deposition power of the CoCrFeNi alloy target to 150W, the Al target to 30-90W, and the Ta target to 40-80W, and pre-sputter the targets for 10 minutes to remove surface contaminants; turn on the nitrogen valve, setting the nitrogen flow rate to 10-20 sccm; open the magnetron target baffle and pre-sputter the metal steel ring (CoCrFeNiAl) X Ta Y )N Z High-entropy alloy thin film sputtering was performed for 140-220 minutes. After deposition, the magnetron target power, magnetron target baffle, nitrogen valve, argon valve, heating and rotation switches, gate valve, molecular pump, mechanical pump, and cooling water unit were sequentially turned off. The film was then cooled to 25°C in a vacuum environment. The vent valve was opened to release gas from the chamber to atmospheric pressure. The chamber door was then opened, and the film deposited on the inner and outer surfaces (CoCrFeNiAl) was removed. X Ta Y )N Z Metal steel rings with high-entropy alloy thin films.

[0022] In this invention, the temperature of magnetron sputtering deposition of the thin film is 400-600℃. Within this temperature range, it is not only conducive to the mutual diffusion of atoms between the high-entropy alloy film and the substrate, forming chemical bonds and increasing the bonding force, but also enables the aging treatment of the 18Ni martensitic aging steel substrate, enhancing the substrate hardness, saving the process of aging separately in a box-type resistance furnace, and improving efficiency.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) This invention uses general-purpose 18Ni martensitic aging steel instead of special martensitic aging steel, and the raw materials are easy to obtain;

[0025] (2) The fatigue strength of the metal steel ring prepared by the present invention is increased by more than 30%, and the wear depth is reduced by more than 70% under the same pin wear test conditions. Attached Figure Description

[0026] Figure 1 : Schematic diagram of the preparation process of the metal steel ring in this invention.

[0027] Figure 2: Schematic diagram of different texture patterns in this invention.

[0028] Figure 3 : Schematic diagram of the magnetron sputtering equipment in this invention.

[0029] Figure 4 : Cross-sectional view of the magnetically controlled target in this invention.

[0030] Figures 3-4 In the middle, 1-frame, 2-rotating motor, 3-pinion, 4-mechanical pump, 5-electromagnetic differential pressure valve, 6-rotating shaft, 7-rotating gear, 8-high vacuum electromagnetic baffle valve, 9-rotating disc, 10-molecular pump, 11-gate valve, 12-molecular pump cooling water inlet, 13-molecular pump cooling water outlet, 14-cooling water unit, 15-magnetic target cooling water inlet, 16-magnetic target cooling water outlet, 17-... 18-Nitrogen valve, 19-Third gas valve, 20-Magnetic target, 21-Magnetic target baffle, 22-Roller, 23-Heating device, 24-Rotating shaft, 25-Heat insulation box, 26-Metal steel ring, 27-Sputtering chamber, 28-Sample stage base, 29-Vent valve, 30-Argon valve, 31-Adjustable connecting rod, 32-Fourth gas valve, 33-Evacuation valve, 34-Computer control platform. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. The present invention provides a metal steel ring in a steel belt assembly for a continuously variable transmission (CVT) and a method for its preparation. The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0032] Example 1: As Figure 1 As shown, the preparation of the metal steel ring in the steel belt assembly for continuously variable transmissions includes the following steps:

[0033] Process 1: Groove textures are prepared on the inner and outer surfaces of general-purpose 18Ni series martensitic aging steel, such as... Figure 2 As shown, it includes the following steps:

[0034] In this embodiment, a metal steel ring (diameter 90.7±0.1mm) was prepared using 18Ni(350) martensitic aging steel plate (285mm long, 12mm wide, and 0.2mm thick). The mass percentage of each component is as follows: nickel: 18.5%, cobalt: 12.1%, molybdenum: 5.3%, titanium: 1.3%, aluminum: 0.15%, carbon: less than 0.02%, silicon: less than 0.01%, sulfur: less than 0.001%, phosphorus: less than 0.001%, and the balance is iron.

[0035] For pretreatment, the surface of the substrate was polished sequentially with silicon carbide sandpaper at grits of 320#, 600#, 1000#, 1500#, and 2000#. After polishing, the substrate was ultrasonically vibrated in acetone for 15 minutes to remove surface impurities. Then, it was ultrasonically vibrated in anhydrous ethanol for 15 minutes to remove residual acetone solution. Finally, the sample was removed and dried. The substrate was fixed on the laser processing platform, and the Nd:YAG pulsed laser was turned on. The laser process parameters were entered as follows: laser power 70W, scanning speed 10mm / s, spot diameter 20μm, pulse width 0.4ms, pulse frequency 25Hz, and 3 scans. Textured patterns of different morphologies were processed on the inner and outer surfaces of the substrate. The specific dimensions were: width 20μm, depth 10μm, inter-texture spacing 200μm, and texture area 30%. After processing, the sample was removed, and the laser was turned off.

[0036] Step two, welding, includes the following steps:

[0037] The plate with the textured morphology was ultrasonically vibrated in acetone for 15 minutes to remove surface oxides; then ultrasonically vibrated in anhydrous ethanol for 15 minutes to remove residual acetone solution; finally, the sample was removed and dried. The welding equipment was turned on, the plate was placed on the welding fixture, and after rounding the plate, it was welded close to the rolled edge. The welding parameters were set as follows: welding power 190W, welding speed 6mm / s, and welding spot size 0.8mm. After welding, the equipment was turned off, and the metal ring with the grooved texture was removed.

[0038] Step 3, such as Figure 3As shown, the magnetron sputtering equipment in this embodiment includes a cavity 27, a frame 1, a substrate heating and rotating stage, a magnetron target 19, a vacuum pumping system, a cooling water unit 14, and a computer control platform 34. The cavity 27 is mounted on the frame 1 and connected to the vacuum pumping system located inside the frame 1. Multiple magnetron targets 19 and magnetron target baffles 20 are evenly distributed on the inner wall of the cavity 27, and multiple gas channels are distributed on the outer wall of the cavity. The substrate heating and rotating stage is installed inside the cavity 27 and consists of two parts: a sample stage and an upper and lower rotating disk 9. The sample stage includes rollers 21, a rotary motor 24, a rotating shaft 23, an adjustable connecting rod 31, and a sample stage base 28. The bottom end of the connecting rod 31 is connected to the spindle 9, and the top end is connected to the sample stage base 28. The position, direction, and angle of the sample stage can be adjusted by adjusting the curvature of the connecting rod 31. The sample stage base 28 has two circular holes for connecting the rotating shaft 23. The rotating shaft 23 is connected to the rotary motor 24 and the rollers 21. The rotary motor 24 is equipped with a heat insulation box 25, and the rollers are equipped with a heating device 22. The sample is placed on the two rollers 21, and the rotating motor 24 drives the rollers 21 to rotate, thus causing the sample to rotate. The working principle of the spindle 9 is that the output end of the spindle 2 is connected to the pinion 3 meshing with the spindle gear 7 inside the frame 1. The spindle gear 7 is equipped with a spindle shaft 6, and the top end of the spindle shaft 6 is connected to the spindle 9, thereby driving the spindle 9 to rotate through gear transmission. In addition, multiple mounting positions for the sample stage connecting rods 31 are arranged in a ring array on the rotating disk 9. The vacuum pumping system includes a mechanical pump 4 and a molecular pump 12. The cooling water unit 14 is equipped with a molecular pump cooling water inlet 12, a molecular pump cooling water outlet 13, a magnetron target cooling water inlet 15, and a magnetron target cooling water outlet 16, mainly for cooling the magnetron target and the molecular pump. The computer control platform 34 controls the heating device and the rotation of the rotating disk in the substrate heating rotating stage.

[0039] Deposited on the surface of a metal steel ring (CoCrFeNiAl) 0.3 Ta 0.4 )N 0.4 High-entropy alloy thin films, comprising the following steps:

[0040] The textured metal ring was ultrasonically cleaned in anhydrous ethanol for 15 minutes to remove surface impurities, and then dried with a blower. The CoCrFeNi high-entropy alloy target, Ta target, and Al target were placed on the magnetron target 19. The cleaned metal ring 13 was then mounted on the two rollers 21 on the sample stage. The angle of the connecting rod 31 was adjusted and fixed to ensure that the metal ring 13 was perpendicular to the magnetron target 19, allowing the sputtered atoms from the target material to deposit onto the inner and outer surfaces of the metal ring. After sample loading, the chamber door 27 was closed, and the vent valve 29 was closed. The mechanical pump 4 and the evacuation valve 33 were turned on, and a vacuum was drawn to 7.0 Pa. The evacuation valve 33 was then closed. The cooling water unit 14 was turned on, and the molecular pump 10 and the gate valve 11 were turned on, and a vacuum was drawn to 2.5 × 10⁻⁶ Pa. -3 Pa. Adjust the gas pressure to 0.9 Pa using gate valve 11. Turn on the heating switch, rotation switch, and rotary switch on the computer control platform 34. Set the substrate temperature to 500℃, the rotation speed of the rotating disk 9 to 15 r / min, and the rotation speed of the roller 21 to 8 r / min. Open the argon valve 30, setting the argon flow rate to 20 sccm. Open the bias switch, setting the bias voltage to 100V. Sequentially perform ignition on the CoCrFeNi alloy target, Al target, and Ta target. After successful ignition, adjust the deposition power of the CoCrFeNi alloy target to 150W, the Al target to 30W, and the Ta target to 40W. Perform pre-sputtering on the targets for 10 minutes to remove surface contaminants. Open the nitrogen valve 17, setting the nitrogen flow rate to 15 sccm. Open the magnetron target baffle 20 and perform (CoCrFeNiAl) sputtering on the metal steel ring. 0.3 Ta 0.4 )N 0.4 High-entropy alloy thin films were deposited over a period of 180 minutes. After deposition, the following were sequentially shut off: magnetron target 19 power, magnetron target baffle 20, nitrogen valve 17, argon valve 30, heating and rotation switches, gate valve 11, molecular pump 10, mechanical pump 4, and cooling water unit 14. The film was cooled to 25°C in a vacuum environment. Venting valve 29 was opened to release gas from chamber 27 to atmospheric pressure. The chamber door was then opened, and the film deposited on the inner and outer surfaces (CoCrFeNiAl) was removed. 0.3 Ta 0.4 )N 0.4 Metal steel rings with high-entropy alloy thin films.

[0041] The metal rings prepared above were subjected to the following performance tests:

[0042] (1) According to GB / T 3075-2008, the fatigue strength of the metal steel ring was tested using an INSTRON 8801 hydraulic servo fatigue testing machine. The test conditions were: loading frequency of 15Hz, stress ratio of 0.1, and temperature of 25℃. The test results are shown in Table 1. The fatigue strength of the metal steel ring was 1269±9.1MPa.

[0043] (2) The wear resistance of the metal steel ring was tested using an MFT-500 friction and wear testing machine. The wear test adopted the pin-disc friction method, with the upper specimen being a cylindrical pin made of bearing steel and the lower specimen being a metal steel ring. During the test, the lower specimen was fixed, while the upper specimen underwent reciprocating friction and wear. The load was set to 80 N, the stroke distance to 100 mm, the frequency to 2 Hz, the temperature to 25 ℃, and the time to 30 min. The lubricating oil used was CVTF-EX1, which needed to cover the surface of the lower specimen. The test results are shown in Table 1. The wear depth of the metal steel ring was 1.31 ± 0.47 μm.

[0044] Examples 2-3:

[0045] The preparation and testing methods for Examples 2-3 are the same as those for Example 1, such as... Figure 2 As shown, the difference lies in the texture morphology, which is circular and rhomboid in Examples 2-3, respectively. The test results of texture morphology, texture area, atomic ratio of film composition, deposition temperature, fatigue strength and wear depth of the metal steel rings prepared in Examples 2-3 are shown in Table 1.

[0046] Examples 4-5:

[0047] The preparation and testing methods for Examples 4-5 are the same as those for Example 1, except that the area occupied by the texture in Examples 4-5 is 20% and 40%, respectively. The test results of the texture morphology, texture area, atomic ratio of film composition, deposition temperature, fatigue strength and wear depth of the metal steel rings prepared in Examples 4-5 are shown in Table 1.

[0048] Examples 6-11:

[0049] The preparation and testing methods for Examples 6-11 are the same as those for Example 1, except that the high-entropy alloy thin films in Examples 6-11 have the following compositions: (CoCrFeNiAl) 0.3 Ta 0.4 )N 0.3 、(CoCrFeNiAl 0.3 Ta 0.4 )N 0.5 、(CoCrFeNiAl 0.3 Ta 0.6 )N 0.4 、(CoCrFeNiAl 0.3 Ta 0.8 )N 0.4 、(CoCrFeNiAl 0.6 Ta 0.4 )N 0.4 、(CoCrFeNiAl 0.9 Ta 0.4 )N 0.4The corresponding process parameters in thin film deposition were nitrogen flow rate of 10 sccm, nitrogen flow rate of 20 sccm, Ta target power of 60 W, Ta target power of 80 W, Al target power of 60 W, and Al target power of 90 W. The test results for the texture morphology, texture area, atomic ratio of film composition, deposition temperature, fatigue strength, and wear depth of the metal steel rings prepared in Examples 6-11 are shown in Table 1.

[0050] Examples 12-13:

[0051] The preparation and testing methods for Examples 12-13 are the same as those for Example 1, except that the film deposition temperatures in Examples 12-13 are 400℃ and 600℃, respectively. The test results for the texture morphology, texture area, atomic ratio of film composition, deposition temperature, fatigue strength, and wear depth of the metal steel rings prepared in Examples 12-13 are shown in Table 1.

[0052] Comparative Example 1

[0053] The preparation methods and testing conditions for steps two and three in Comparative Example 1 are the same as in Example 1, except that textures with different morphologies are not prepared on the inner and outer surfaces of the general 18Ni martensitic aging steel. The test results of the atomic ratio of film composition, deposition temperature, fatigue strength and wear depth of the metal steel ring prepared in Comparative Example 1 are shown in Table 1.

[0054] Comparative Example 2: The traditional process for preparing metal steel rings includes the following steps:

[0055] Step 1: Welding of the special martensitic aging steel, including the following steps:

[0056] In this comparative example, a 0.2 mm thick special martensitic aging steel plate was used to prepare the metal steel ring. The mass percentage of each component was as follows: nickel: 18.5%, cobalt: 15.4%, molybdenum: 5.6%, carbon: less than 0.02%, silicon: less than 0.01%, sulfur: less than 0.001%, phosphorus: less than 0.001%, and the balance was iron.

[0057] The plate was ultrasonically vibrated in acetone for 15 minutes to remove surface oxides; then ultrasonically vibrated in anhydrous ethanol for 15 minutes to remove residual acetone solution; finally, the sample was removed and dried. The welding equipment was turned on, the plate was placed on the welding fixture, and after rounding the plate, it was welded close to the rolled edge. The welding parameters were set as follows: welding power 190W, welding speed 6mm / s, and welding spot size 0.8mm. After welding, the metal ring was removed, and the equipment was turned off.

[0058] Step two involves strengthening the metal ring, including the following steps:

[0059] Metal steel rings were subjected to solution treatment in a box-type resistance furnace at a temperature of 830℃ for 60 minutes, with air cooling. The solution-treated steel rings were then aged in the same furnace at 500℃ for 180 minutes, with air cooling again. The solution-treated and aged steel rings were then polished with silicon carbide sandpaper in the order of 600#, 1000#, 1500#, and 2000# grit. The surface was first ultrasonically vibrated in acetone for 15 minutes to remove impurities, then ultrasonically vibrated in anhydrous ethanol for 15 minutes to remove residual acetone solution. Finally, the samples were removed and dried. The cleaned steel rings were then placed in a pit-type gas nitriding furnace at a nitriding temperature of 480℃ for 12 hours, with furnace cooling.

[0060] The performance testing method is the same as in Example 1, and the test results are shown in Table 1.

[0061] Table 1 shows the process parameters and performance test results of the metal steel rings prepared in Examples 1-13 and Comparative Examples 1-2 of this invention.

[0062]

[0063] 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 principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A metal steel ring in a steel belt assembly for a continuously variable transmission, characterized in that, The metal steel ring is made of a general 18Ni series maraging steel with a laser texturing pattern on both sides in a strip shape, welded into a circular ring, and then (CoCrFeNiAl X Ta Y )N Z High-entropy alloy film The temperature of the magnetron sputtering is 500℃; (CoCrFeNiAl X Ta Y )N Z wherein X, Y, Z represent atomic ratio, X = 0.3-0.9, Y = 0.4-0.8, Z = 0.3-0.5, Co, Cr, Fe, Ni are equal atomic ratio 1.

2. The metal ring for a steel belt assembly for a continuously variable transmission according to claim 1, characterized in that, The general 18Ni series maraging steel has the following components in percentage by mass: nickel 16-19%, cobalt 10-13%, molybdenum 4-6%, titanium 1-2%, aluminum <0.2%, carbon <0.02%, silicon <0.01%, sulfur <0.001%, phosphorus <0.001%, and the balance of iron.

3. The metal ring for a steel belt assembly for a continuously variable transmission according to claim 1, characterized in that, The laser texturing pattern is: groove-shaped, circular or diamond-shaped.

4. The metal ring for a steel belt assembly for a continuously variable transmission according to claim 1, characterized in that, (CoCrFeNiAl X Ta Y )N Z The thickness of the high-entropy alloy film was 4-6 pm.

5. The method for preparing the metal steel ring in the continuously variable transmission (CVT) steel belt assembly as described in claim 1, characterized in that, The method comprises the following steps: (1) preparing a texturing pattern on two surfaces of a strip-shaped general 18Ni series maraging steel by using a laser; (2) welding the strip-shaped general 18Ni series maraging steel treated in step (1) into a metal steel ring; (3) depositing (CoCrFeNiAl X Ta Y )N Z high-entropy alloy thin films on the inner and outer walls of the metal steel ring obtained in step (2) by magnetron sputtering.

6. The method for preparing the metal steel ring in the continuously variable transmission (CVT) steel belt assembly as described in claim 5, characterized in that, The operation method of step (1) is as follows: Use silicon carbide sandpaper to polish the surfaces of the strip-shaped general 18Ni series maraging steel in the order of 320#, 600#, 1000#, 1500# and 2000#, and then place the polished steel in acetone for ultrasonic oscillation for 15 min, wash off the impurities on the surface, and then place the steel in anhydrous ethanol for ultrasonic oscillation for 15 min, wash off the residual acetone solution, and finally dry the steel; fix the pretreated strip-shaped general 18Ni series maraging steel on a laser processing workbench, turn on the laser switch, and input the laser process parameters: laser power 60-80 W, scanning speed 5-20 mm / s, spot diameter 10-30 μm, pulse width 0.2-0.6 ms, pulse frequency 15-30 Hz, and scanning times 2-4 times; process the texturing pattern on the two surfaces of the steel, and the texture size is width 10-40 μm, depth 5-20 μm, texture interval 100-300 μm, and texture area ratio 20-40%; after the processing, take out the steel, and turn off the laser switch.

7. The method for preparing the metal steel ring in the continuously variable transmission (CVT) steel belt assembly as described in claim 5, characterized in that, The welding in step (2) is performed by laser welding or argon arc welding.

8. The method for preparing the metal steel ring in the continuously variable transmission (CVT) steel belt assembly as described in claim 5, characterized in that, The equipment for magnetron sputtering in step (3) comprises a cavity, a rack, a substrate heating self-rotating table, a magnetron target, a vacuum pumping system, a cooling water unit and a computer control platform; the cavity is installed on the rack and connected with the vacuum pumping system in the rack, a plurality of magnetron targets and magnetron target baffles are uniformly distributed on the inner wall of the cavity, and a plurality of gas channels are distributed on the outer wall of the cavity; the substrate heating self-rotating table is installed inside the cavity, and the self-rotating table is divided into an upper sample table and a lower self-rotating disc; the sample table comprises rollers, a rotating motor, a rotating shaft, an adjustable connecting rod and a sample table base, the bottom end of the connecting rod is connected with the self-rotating disc, the top end of the connecting rod is connected with the sample table base, and the position direction and angle of the sample table can be adjusted by adjusting the curvature of the connecting rod; two circular holes are arranged on the sample table base for connecting the rotating shaft, the rotating motor and the rollers are connected on the rotating shaft, the rotating motor is provided with a heat insulation box outside, the rollers are provided with a heating device inside, the sample is placed on the two rollers, and the sample is driven to rotate by the rotating motor; a plurality of mounting positions for mounting the connecting rods of the sample tables are arranged in an annular array on the self-rotating disc; the vacuum pumping system comprises a mechanical pump and a molecular pump; the cooling water unit is provided with a molecular pump cooling water inlet, a molecular pump cooling water outlet, a magnetron target cooling water inlet and a magnetron target cooling water outlet for cooling the magnetron target and the molecular pump; and the computer control platform controls the heating device in the substrate heating self-rotating table and the self-rotation of the self-rotating disc.

9. The method for preparing the metal steel ring in the continuously variable transmission (CVT) steel belt assembly as described in claim 8, characterized in that, Deposition of (CoCrFeNiAl X Ta Y )N Z on the inner and outer walls of a metallic steel ring A method for producing a high-entropy alloy thin film is as follows: The metal steel ring with a textured morphology is placed in anhydrous ethanol and ultrasonically cleaned for 15 min, the surface residual impurities are washed away, and the metal steel ring is dried by a hair dryer; a CoCrFeNi high-entropy alloy target, a Ta target and an Al target are placed on a magnetron target, the cleaned metal steel ring is loaded on the two rollers of the sample table, the connecting rod angle is adjusted and fixed, the metal steel ring is ensured to be perpendicular to the magnetron target, and the atoms sputtered from the target material can be deposited on the inner and outer surfaces of the metal steel ring; after the sample is loaded, the cavity chamber door is closed, and the air release valve is closed; the mechanical pump and the air valve are opened, the vacuum is pumped to below 8.0 Pa, and the air valve is closed; Turn on the cooling water unit switch, open the molecular pump and gate valve, and vacuumize to 3.0*10 -3 Pa; adjust the air pressure to 0.8-1 Pa by using the gate valve; turn on the heating switch, the self-rotation switch and the rotation switch on the computer control platform, the substrate temperature is 500 DEG C, the self-rotation disc rotation speed is 10-20 r / min, and the roller rotation speed is 5-10 r / min; turn on the argon valve switch, the argon flow is 10-30 sccm; turn on the bias switch, the bias is 80-120 V; sequentially ignite the CoCrFeNi alloy target, the Al target and the Ta target, after successful ignition, adjust the CoCrFeNi alloy target deposition power to 150 W, the Al target deposition power to 30-90 W, and the Ta target deposition power to 40-80 W, pre-sputter the target material, and the sputtering time is 10 min to remove the surface contaminants of the target material; Open the nitrogen valve switch, the nitrogen flow is 10-20sccm; open the magnetron target baffle, and sputter (CoCrFeNiAl X Ta Y )N Z Sputter the high-entropy alloy film, and the sputtering time is 140-220min; after the film deposition is completed, sequentially close the magnetron target power, the magnetron target baffle, the nitrogen valve, the argon valve, the heating and self-rotation switch, the gate valve, the molecular pump, the mechanical pump, and the cooling water unit; cool to 25℃ in the vacuum environment, open the air release valve to release the cavity to the atmospheric pressure, open the cavity chamber door, and take out the metal steel ring with the (CoCrFeNiAl X Ta Y )N Z High-entropy alloy film deposited on the inner and outer surfaces.

Images