A high load type load wheel forming process

Abstract

The present application relates to the technical field of forming technology of support wheel, and particularly relates to a high-load support wheel forming process. The structure comprises the steps of forging forming, quenching, tempering, machining, rim surface treatment, post-treatment and assembly. The present application solves the problems of large quenching crack tendency, insufficient rim wear resistance and difficult oxide skin cleaning in the existing support wheel manufacturing process, and brings the effects of comprehensive mechanical property improvement, no quenching crack, high rim wear resistance, energy saving and environmental protection and automatic continuous production, and is mainly applied to the manufacturing of high-load support wheels of excavators, bulldozers, cranes and other tracked engineering machinery.

Description

Technical Field

[0001] This invention relates to the field of track roller forming technology, and in particular to a high-load track roller forming process. Background Technology

[0002] Track rollers are key load-bearing components of the chassis system of tracked construction machinery (such as excavators, bulldozers, and cranes). Operating under heavy loads, low speeds, high impacts, and harsh muddy environments, they require extremely high wear resistance, fatigue strength, and impact toughness. Current technology typically employs a "forging + reheating + overall oil quenching or water quenching + low-temperature tempering" process for track roller manufacturing. This method has the following drawbacks: single-medium quenching makes it difficult to balance deformation control and microstructure hardness requirements; oil quenching results in insufficient hardness; and water quenching easily leads to cracking. Using the same heat treatment process for the wheel rim working surface and the base material results in insufficient wear resistance of the wheel rim and a relatively short overall lifespan. Furthermore, the oxide scale and debris generated during quenching are difficult to clean, affecting continuous production. Summary of the Invention

[0003] Therefore, in view of the above problems, the present invention proposes a high-load type support roller forming process, which solves the technical problems of high quenching crack tendency, insufficient wear resistance of wheel rim and difficulty in removing oxide scale in the existing support roller manufacturing.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: including forging, quenching, tempering, machining, rim surface treatment, post-treatment, and assembly steps, specifically including the following steps:

[0005] S1. Heat the alloy structural steel billet to 1050℃~1150℃ and perform closed-die forging to obtain the support roller forging billet. Control the final forging temperature to 780℃~810℃.

[0006] S2. Using the final forging temperature, a composite medium graded quenching is performed on the forging billet using a contour induction hardening device. Combined with the quenching treatment structure 3, the forging billet undergoes segmented quenching. During the quenching process, a segmented cooling mode with progressively increasing cooling rates is adopted. The quenching media for each segment are continuously sprayed and switched through a spray device 4, ensuring no air exposure gaps on the surface of the forging billet throughout the entire process.

[0007] S21. First stage quenching: Cooling is achieved by spraying quenching oil at a temperature of 60℃~100℃ for 10s~25s.

[0008] S22. Second stage quenching: Cooling is carried out by spraying clean water at a temperature of 15℃~30℃ for 2s~5s.

[0009] S23. Third stage quenching: Cooling is achieved by spraying with brine at a temperature of 10℃~25℃ and a mass fraction of 8%~12%, with a cooling time of 1s~3s.

[0010] S3. Temper the quenched support rollers at 450℃~550℃ for 60min~120min.

[0011] S4. Perform precision machining on the tempered support rollers to ensure the external dimensions and assembly accuracy.

[0012] S5. The working surface of the support roller is subjected to targeted induction hardening to make the surface hardness of the rim reach HRC52~58 and the hardened layer depth 5mm~10mm.

[0013] S6. Complete the post-processing of the workpiece and the overall assembly in sequence to obtain the finished high-load type support roller.

[0014] Furthermore, the final forging temperature in step S1 is achieved by controlling the mold opening time and / or setting a heat preservation device, so that the forging billet enters the first stage of quenching in step S2 within 3s to 8s after leaving the mold.

[0015] Furthermore, the alloy structural steel is a medium-carbon alloy steel with a carbon content of 0.45% to 0.55%; the chemical composition of the steel contains composite microalloying elements, including at least one of 0.02% to 0.05% by mass of niobium (Nb) and 0.05% to 0.12% by mass of vanadium (V).

[0016] Furthermore, the contour induction hardening device includes a main body, a control and processing box, a hardening treatment structure, a spraying device, a workpiece placement platform, and a hardening auxiliary cleaning mechanism. The control and processing box is installed on the surface of the main body, and the hardening treatment structure is electrically connected to the control and processing box. The hardening treatment structure includes a large induction section corresponding to the end of the support roller and a small induction section corresponding to the other side of the support roller. The small induction section and the large induction section, when enclosed, are consistent with the structure of the support roller. The spraying device is located below the small induction section and the large induction section. The workpiece placement platform is axially collinear with the spraying device and the hardening treatment structure. The hardening auxiliary cleaning mechanism is located inside the main body of the device.

[0017] Furthermore, the quenching structure includes a mounting plate and two symmetrically arranged processing units. The mounting plate has a lifting rod on its surface, and a connecting plate is mounted on the lifting rod. The other end of the connecting plate is connected to the large induction section in conjunction with a heat-conducting strip. A heat-conducting plate is mounted on the surface of each processing unit, and a telescopic drive component is also mounted on the surface of the processing unit. The telescopic end of the telescopic drive component is connected to the small induction section in conjunction with the connecting component. The small induction section is connected to the processing unit through a heat-conducting strip.

[0018] Furthermore, in step S2, the three quenching media are supplied independently and switched sequentially through a spray device, with the switching time between adjacent media not exceeding 0.5s. The spray device includes a spray frame, inside which are three equally spaced flow chambers. Water inlet pipes are symmetrically installed on the surface of the spray frame. The water inlet pipes are arranged in groups of three, and each water inlet pipe is connected to one of the three flow chambers. The inner wall of the spray frame is surrounded by spray pipes that are connected to each flow chamber and are arranged in a uniform array.

[0019] Furthermore, the water outlet end of each spray pipe is equipped with a fan-shaped spray plate. The three sets of spray pipes, corresponding to different quenching media, have their fan-shaped spray plates installed differently in a vertical and horizontal staggered arrangement to achieve uniform cooling of the entire support roller.

[0020] Furthermore, the quenching auxiliary cleaning mechanism includes a receiving plate, a waste chip conveying assembly, a centralized collection frame, a waste chip lifting assembly, a scraper, and a drive frame; the receiving plate adopts a hollow filter screen structure; the waste chip conveying assembly is installed at the edge of the receiving plate; the discharge end of the waste chip conveying assembly is connected to the centralized collection frame; the waste chip lifting assembly is assembled on the outside of the centralized collection frame for directional discharge of waste residue; and the scraper is installed at the output end of the receiving plate for scraping off and collecting quenching waste residue and oxide scale.

[0021] The waste conveying assembly and the waste lifting assembly have the same structure, both consisting of a mesh conveying plate and a drive motor;

[0022] The drive frame integrates a hydraulic push rod, which drives the scraper to perform reciprocating linear motion.

[0023] Furthermore, the scraping component includes a movable plate, a scraper, a cleaning strip, and a flexible pusher. The scraper has a triangular structure and is fixed to the bottom of the movable plate as an integral structure. The cleaning strip is detachably assembled to the lower surface of the movable plate and fits against the rear side of the scraper. Two sets of movable plates are symmetrically arranged, and the two sets of movable plates are respectively connected to the hydraulic push rod inside the drive frame. Flexible pushers are fixed to the opposite ends of the two sets of movable plates.

[0024] Furthermore, the waste conveying assembly also includes an adjustable scraper, which is installed at one end of the waste conveying assembly near the centralized collection frame.

[0025] By adopting the aforementioned technical solution, the beneficial effects of the present invention are:

[0026] This invention achieves an excellent combination of no quenching cracks, high core toughness, high wear resistance of the rim, and long fatigue life through a synergistic process of "direct utilization of forging waste heat + graded quenching with oil, water, and brine + high-temperature tempering + independent induction strengthening of the rim". The overall performance is improved by more than 72% compared with the traditional process.

[0027] Using the final forging temperature (780℃~810℃) directly for subsequent stage quenching not only saves energy but also avoids surface oxidation and decarburization caused by reheating.

[0028] A three-stage composite medium quenching process using "oil + water + brine" with progressively accelerated cooling is employed. The first stage uses oil cooling to reduce thermal stress, the second stage uses water cooling to quickly avoid the bainite region, and the third stage uses brine to enhance martensitic transformation. By controlling the cooling time and switching speed of each stage, the risk of cracking is significantly reduced while ensuring hardenability.

[0029] Furthermore, the heat-conducting structure in the contour induction hardening device is used to prevent overheating of the induction section, the differentiated arrangement of the fan-shaped spray plates ensures uniform cooling, the switching time is ≤0.5s to achieve no air exposure, the hardening auxiliary cleaning mechanism realizes automatic removal of waste chips, and the cooperation of each structure ensures stable execution of the process.

[0030] Meanwhile, by setting up three independent chambers for different media and different arrangements of fan-shaped spray plates, and with a switching time of no more than 0.5 seconds, it is ensured that there are no air exposure gaps on the surface of the forging billet, and the microstructure transformation is excellent.

[0031] The quenching auxiliary cleaning mechanism utilizes the reciprocating motion of the scraper and the hollow receiving plate to efficiently remove the oxide scale and waste chips that fall off during graded quenching, preventing blockages. It also avoids the waste chips being carried up or stuck to the workpiece surface after the workpiece is immersed in the cooling water during the quenching cooling process. This mechanism is suitable for automated continuous production. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the quenching treatment structure of the present invention;

[0034] Figure 3 This is a schematic diagram of the spray device of the present invention;

[0035] Figure 4 This is the present invention. Figure 3 Schematic diagram of the structure of AA;

[0036] Figure 5 This is a schematic diagram of the quenching auxiliary cleaning mechanism of the present invention. Figure 1 ;

[0037] Figure 6 This is a schematic diagram of the quenching auxiliary cleaning mechanism of the present invention. Figure 2 ;

[0038] In the diagram: Main body of the device-1, Control and processing box-2, Quenching treatment structure-3, Mounting plate-31, Lifting rod-32, Connecting plate-33, Large induction section-34, Processing unit-35, Heat-conducting plate-36, Telescopic drive component-37, Connecting component-38, Small induction section-39, Heat-conducting strip two-310, Heat-conducting strip one-341, Spraying device-4, Spraying frame-41, Flow chamber-411, Water inlet pipe-42, Spraying pipe-43, Fan-shaped spray plate-431, Workpiece placement platform-5, Quenching auxiliary cleaning mechanism-6, Receiving plate-61, Waste chip conveying component-62, Centralized collection frame-63, Waste chip lifting component-64, Scraper component-65, Drive frame-66, Movable plate-651, Scraper-652, Cleaning strip-653, Flexible pusher-654, Adjustable scraper-621. Detailed Implementation

[0039] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. Example 1

[0040] This embodiment provides a high-load-bearing support roller forming process, which includes forging, quenching, tempering, machining, rim surface treatment, post-treatment, and assembly steps, specifically including the following steps:

[0041] S1. Select a medium carbon alloy steel billet with a carbon content of 0.5%, add 0.03% niobium (Nb) and 0.08% vanadium by mass to the steel, heat the billet to 1100℃, and perform closed die forging on a 1600-ton closed press to obtain a support roller forging billet. By controlling the air cooling time after the die is opened and the heat preservation conveying channel, the final forging temperature is stabilized at 795±15℃. Within 5 seconds after the forging billet leaves the die, it is automatically transferred by a robot to the workpiece placement table 5 of the contour induction hardening device.

[0042] S2. Utilizing the final forging temperature, activate the lifting rod 32 and the telescopic drive component 37 to maintain a 2-3mm contour gap between the large induction section 34 and the small induction section 39 and the support roller forging blank. Control the processing box 2 to activate the spray device 4 according to the preset timing sequence. The workpiece placement table 5 drives the support roller to rotate at 30r / min. The specific segmentation is as follows:

[0043] S21. First stage quenching: Open the flow chamber corresponding to the quenching oil, spray 80°C quenching oil through the vertically arranged fan-shaped spray plates 431, cool for 15 seconds, and at the same time cut off the induction heating power supply. The workpiece relies on residual heat to cool itself.

[0044] Switching time: 0.3s (seamless switching controlled by a high-speed solenoid valve);

[0045] S22, Second stage quenching: Close the quenching oil circuit, immediately open the flow chamber corresponding to the clean water, and spray 25°C clean water through the horizontally staggered fan-shaped spray plates 431, and cool for 3 seconds.

[0046] Switching time: 0.3s;

[0047] S23, Third stage quenching: Close the clean water circuit, open the flow chamber corresponding to the brine (mass fraction 10%), spray 20℃ brine through the fan-shaped spray plate 431, and cool for 2 seconds;

[0048] Throughout the entire process, there is no air exposure on the surface of the forging billet. In the quenching treatment structure 3 of the contour induction hardening device, the large induction section 34 is precisely fitted with the end of the support roller, and the small induction section 39 is fitted with the other side of the support roller after the position is adjusted by the telescopic drive component 37. The three sets of spray pipes of the spray device 4 are vertically and horizontally staggered, and the switching time between adjacent media is 0.3s. The quenching auxiliary cleaning mechanism 6 works normally and cleans up waste residue and oxide scale in a timely manner.

[0049] S3. After quenching, the support roller is kept at 500℃ for 90 minutes, then cooled in the furnace to below 300℃ and air-cooled to obtain tempered sorbite structure.

[0050] S4. High-precision CNC machine tools are used to turn, mill, drill and grind the tempered support rollers. The tolerance of the wheel flange diameter is controlled to be ±0.02mm, the tolerance of the wheel flange thickness is ±0.01mm, and the coaxiality of the mounting holes is 0.015mm. After machining, grinding and polishing are performed.

[0051] S5. Secondary strengthening treatment of wheel flange surface: Using an independent induction hardening machine tool, the working surface of the wheel flange of the support roller is subjected to scanning hardening; Parameters: frequency 8kHz, power 60kW, scanning speed 180mm / min, self-tempering, after treatment the surface hardness of the wheel flange reaches HRC55, and the hardened layer depth is 7mm.

[0052] S6. The surface of the support roller is cleaned with ultrasonic cleaning, and rust-proof paint is sprayed for rust prevention. After passing the ultrasonic flaw detection, the support roller is assembled with the shaft, bearings, seals and other components. After passing the no-load test and load test, it is packaged and put into storage.

[0053] Among them, reference Figures 1-6 The above-mentioned contour induction hardening device includes a main body 1, a control processing box 2, a hardening processing structure 3, a spraying device 4, a workpiece placement platform 5, and a hardening auxiliary cleaning mechanism 6. The control processing box 2 is installed on the surface of the main body 1 and is used to control the timing, medium switching, and motion execution of the entire hardening process. It is equipped with a PLC controller and a high-speed solenoid valve drive circuit. The hardening processing structure 3, the spraying device 4, the workpiece placement platform 5, and the hardening auxiliary cleaning mechanism 6 are all electrically connected to the control processing box 2.

[0054] The quenching treatment structure 3 is electrically connected to the control processing box 2. Further, the quenching treatment structure 3 includes a mounting plate 31 and two symmetrically arranged processing units 35. The mounting plate 31 has a lifting rod 32 on its surface, and a connecting plate 33 is mounted on the lifting rod 32. The other end of the connecting plate 33 is connected to the large induction section 34 via a heat-conducting strip 341. A heat-conducting plate 36 is mounted on the surface of each processing unit 35, and a telescopic drive component 37 is also mounted on the surface of each processing unit 35. It should be noted that in this embodiment, the telescopic drive component 37 is preferably a servo cylinder or an electric push rod; however, the appropriate type can be selected based on actual conditions in practical applications. The telescopic end of the telescopic drive component 37 is connected to the small induction section 39 via a connecting piece 38, and the small induction section 39 is connected to the processing unit 35 via a heat-conducting strip 310.

[0055] The quenching structure 3 includes a large induction section 34 corresponding to the end of the support wheel and a small induction section 39 corresponding to the other side of the support wheel. The small induction section 39 and the large induction section 34, when combined, form a structure consistent with the support wheel. The large induction section 34 is a cylindrical shape with one open end, and its inner cavity shape is similar to the outer contour of the large end of the support wheel (i.e., the transition area between the wheel rim and the wheel body). The small induction section 39 is an arc-shaped panel, and its concave curved surface shape is similar to the outer contour of the small end of the support wheel (i.e., the journal end). The specific structural arrangement of the large induction section 34 and the small induction section 39 can be customized according to the structure of the actual workpiece. In the quenching working state, the lifting rod 32 drives the large induction section 34 to move from top to bottom, fitting around the outer end of the support wheel; simultaneously, the two symmetrically arranged small induction sections 39, pushed by the telescopic drive 37, converge from both sides of the lower end of the support wheel towards the center. When the lower end face of the large induction section 34 and the concave curved surfaces of the two small induction sections 39 completely cover the circumferential surface of the small end of the support roller, the small induction section 39 and the large induction section 34 together form a cavity that is consistent with the overall outer contour shape of the support roller. A 2-3 mm induction heating gap (non-contact type) is maintained between the cavity and the outer surface of the support roller.

[0056] Specifically, the aforementioned heat-conducting strip 341, heat-conducting strip 310, and heat-conducting plate 36 are all made of materials with a thermal conductivity greater than or equal to 380 W / (m·K), such as copper or copper alloy. It should be noted that the mounting plate 31 is also equipped with a heat dissipation structure; in this embodiment, this heat dissipation structure is an air-cooled fin, but it can be selected according to the actual application. An independent air-cooled or water-cooled radiator is installed on the heat-conducting plate 36, which can also be selected according to the actual application. During induction hardening, the large induction section 34 and the small induction section 39 generate a large amount of heat due to the eddy current effect. If this heat is not dissipated in time, it will cause the induction section to overheat, deform, soften, or even burn out. One end of the heat-conducting strip 341 is fixedly connected to the large induction section 34, and the other end is thermally connected to the heat dissipation structure (such as air-cooled fins) on the mounting plate 31 through the connecting plate 33, thereby quickly dissipating the heat from the large induction section 34. Similarly, heat-conducting strip 310 connects the small induction section 39 to the heat-conducting plate 36 on the surface of the processing unit 35. An independent air-cooled or water-cooled radiator is installed on the heat-conducting plate 36. Through the above heat conduction path, the temperature of the induction section is always controlled below 150℃, ensuring the stability of long-term operation and the accurate output of heating power.

[0057] The spray device 4 includes a spray frame 41, inside which are three equally spaced flow chambers 411. Water inlet pipes 42 are symmetrically installed on the surface of the spray frame 41. The water inlet pipes 42 are arranged in groups of three, and each water inlet pipe 42 is connected to one of the three flow chambers 411. Spray pipes 43 are arranged in a uniform array around the inner wall of the spray frame 41, which are connected to each flow chamber 411.

[0058] Each inlet pipe 42 is equipped with a high-speed solenoid valve (response time ≤ 0.05s) at the connection between itself and the flow chamber 411. The PLC in the control processing box 2 issues commands according to a preset timing sequence: 0.1s before the end of the first stage quenching, the high-speed solenoid valve corresponding to the second stage begins to be pre-energized. Simultaneously, the second stage solenoid valve is fully open when the first stage solenoid valve closes, ensuring seamless media connection. At the same time, the spray pipes 43 of the three flow chambers are staggered circumferentially, and the fan-shaped spray plates of adjacent spray systems have a 5-10mm overlap coverage area. Therefore, at the moment of media switching, the surface of the forging billet always has a residual liquid film of the previous medium that has not yet dried before the second medium is sprayed on, preventing air exposure. Actual measurements show that the flow interruption time during the switching process is ≤ 0.3s.

[0059] The water outlet of each spray pipe 43 is equipped with a fan-shaped spray plate 431. The three sets of spray pipes 43, which correspond to different quenching media, have their fan-shaped spray plates arranged vertically, staggered horizontally, and differently installed to achieve uniform cooling of the entire support roller.

[0060] The quenching auxiliary cleaning mechanism 6 includes a receiving plate 61, a waste chip conveying assembly 62, a centralized collection frame 63, a waste chip lifting assembly 64, a scraper 65, and a drive frame 66. The receiving plate 61 adopts a hollow filter screen structure and is located below the workpiece placement platform to receive dripping quenching media and detached oxide scale. The waste chip conveying assembly 62 is installed at the edge of the receiving plate 61, and its discharge end connects to the centralized collection frame 63. The waste chip lifting assembly 64 is assembled on the outside of the centralized collection frame 63 for directional discharge of waste residue. The scraper 65 is installed at the output end of the receiving plate 61 to scrape off and collect the quenching waste residue and oxide scale adhering to the receiving plate.

[0061] The waste chip conveying assembly 62 and the waste chip lifting assembly 64 have the same structure, both consisting of a mesh conveyor plate and a drive motor;

[0062] The drive frame 66 integrates a hydraulic push rod, which drives the scraper 65 to perform reciprocating linear motion.

[0063] Specifically, the scraper component 65 includes a movable plate 651, a scraper 652, a cleaning strip 653, and a flexible pusher 654. The scraper 652 has a triangular structure (the cross-section is a right triangle). The scraper 652 is fixed to the bottom of the movable plate 651 and is an integral structure. In this embodiment, the cleaning strip 653 is detachably assembled to the lower surface of the movable plate 651 and fits against the rear side of the scraper 652 by Velcro or screws. Two sets of movable plates 651 are symmetrically arranged. The two sets of movable plates 651 are respectively connected to the hydraulic push rod inside the drive frame 66. The flexible pusher 654 is fixed to the opposite ends of the two sets of movable plates 651.

[0064] During operation, the hydraulic push rods within the drive frame 66 drive two sets of movable plates 651 to perform reciprocating linear motion in opposite directions (moving from both ends of the receiving plate 61 towards the middle, and then returning to their original positions). The sequence of coordinated actions is as follows: When the two sets of movable plates 651 move towards the discharge end of the waste conveying assembly 62, the flexible pusher 654 moves synchronously with the movable plates 651, and when passing the workpiece placement table 5, the flexible pusher 654 will bypass the workpiece placement table 5 to push the material. The cutting edge of the triangular scraper 652 is in close contact with the surface of the receiving plate, scooping up the waste debris on the surface of the receiving plate 61 and pushing it forward to the entrance of the waste conveying assembly 62. During this process, the cleaning strip 653 will also sweep the iron filings along this path to prevent them from adhering to the surface of the receiving plate 61. When the movable plate 651 retracts, the cleaning strip 653 sweeps off the small particles remaining on the cutting edge of the scraper 652 to prevent them from being carried back to the cleaned area.

[0065] Furthermore, the waste conveying assembly 62 also includes an adjustable scraper 621. The adjustable scraper 621 is installed at one end of the waste conveying assembly 62 near the centralized collection frame 63. When the waste layer on the conveying plate is too thick, the adjustable scraper 621 scrapes off the excess waste, preventing blockage at the entrance of the centralized collection frame 63. At the same time, the scraper can also forcibly peel off wet waste adhering to the conveying plate, improving the waste removal efficiency. Preferably, the adjustable scraper 621 is made of wear-resistant stainless steel, and its lower edge is machined into a serrated shape. The specific design can also be adjusted according to the actual application. Example 2

[0066] The difference between this embodiment and Embodiment 1 is as follows: S1 final forging temperature 780℃; S21: quenching oil temperature 60℃ / 25s; S22: clean water 15℃ / 5s; S23: brine mass fraction 8% / 10℃ / 3s; S3: tempering 450℃ / 120min; S5: rim hardness HRC52, hardened layer depth 5mm. All other steps are the same. Example 3

[0067] The difference between this embodiment and Embodiment 1 is as follows: S1 final forging temperature 810℃; S21: quenching oil temperature 100℃ / 10s; S22: clean water 30℃ / 2s; S23: brine mass fraction 12% / 25℃ / 1s; S3: tempering 550℃ / 60min; S5: rim hardness HRC58, hardened layer depth 10mm. All other steps are the same.

[0068] Comparative Example 1

[0069] This comparative example uses a conventional process: the same steel as in Example 1 is used, and the conventional "reheating oil quenching + low-temperature tempering" process is employed: the forging is heated to 850℃ and held for 2 hours, then immersed in 80℃ quenching oil for cooling, and finally tempered at 200℃ for 2 hours. No secondary strengthening treatment of the rim is performed. The remaining machining steps are the same.

[0070] Comparative Example 2

[0071] This comparative example uses single-water quenching: it employs the same forging residual heat (final forging temperature 795℃) and the same contour-following induction spraying device as the present invention, but only uses 25℃ clean water for continuous spraying cooling (no segmented switching, no oil and brine sections), with a total cooling time of 20s. Subsequent tempering, rim strengthening, and other steps are the same as in Example 1.

[0072] Comparative Example 3

[0073] This comparative example uses the same three-stage switching mode and switching time as the present invention, but the medium switching order is reversed: the first stage is brine (20℃ / 2s), the second stage is clean water (25℃ / 3s), and the third stage is quenching oil (80℃ / 15s). Other steps are the same as in Example 1.

[0074] The following performance tests were performed on the support rollers obtained in Examples 1-3 and Comparative Examples 1-3:

[0075]

[0076] As can be seen from the table above, the overall performance of Examples 1-3 of the present invention is significantly better than that of the comparative examples, achieving an excellent combination of high hardness, high toughness, low wear, long life and no cracks.

[0077] In summary, Example 1 exhibits the best overall performance; Example 2 has the highest toughness and is suitable for high-impact conditions; Example 3 has the highest hardness and the least wear, making it suitable for extreme wear conditions.

[0078] The process of this invention patent achieves a significant improvement in the comprehensive mechanical properties and service life of the track roller through a specific sequence of three-stage graded quenching (oil → water → brine) + rapid switching without air exposure + high-temperature tempering + secondary strengthening of the wheel rim, and there are no quenching cracks. The technical effect is significantly better than the existing technology.

[0079] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A high-load-bearing support roller forming process, comprising forging, quenching, tempering, machining, rim surface treatment, post-treatment, and assembly steps, characterized in that, Includes the following steps: S1. Heat the alloy structural steel billet to 1050℃~1150℃ and perform closed-die forging to obtain the support roller forging billet. Control the final forging temperature to 780℃~810℃. S2. Using the final forging temperature, the forging blank is subjected to composite medium graded quenching using a contour induction hardening device. The forging blank is then subjected to segmented quenching using the quenching treatment structure in the contour induction hardening device. During the quenching process, a segmented cooling mode with progressively increasing cooling rate is adopted. The quenching medium for each segment is continuously sprayed and switched through the spray device in the contour induction hardening device. There are no air exposure gaps on the surface of the forging blank throughout the entire process. S21. First stage quenching: Cooling is achieved by spraying quenching oil at a temperature of 60℃~100℃ for 10s~25s. S22. Second stage quenching: Cooling is carried out by spraying clean water at a temperature of 15℃~30℃ for 2s~5s. S23. Third stage quenching: Cooling is achieved by spraying with brine at a temperature of 10℃~25℃ and a mass fraction of 8%~12%, with a cooling time of 1s~3s. S3. Temper the quenched support rollers at 450℃~550℃ for 60min~120min. S4. Perform precision machining on the tempered support rollers to ensure the external dimensions and assembly accuracy. S5. Perform targeted induction hardening on the working surface of the support roller flange to achieve a surface hardness of HRC52-58 and a hardened layer depth of 5mm-10mm. S6. Complete the post-processing of the workpiece and the overall assembly in sequence to obtain the finished high-load type support roller.

2. The high-load-bearing support roller forming process according to claim 1, characterized in that: The final forging temperature in step S1 is achieved by controlling the mold opening time and / or setting a heat preservation device, so that the forging billet enters the first stage of quenching in step S2 within 3s to 8s after leaving the mold.

3. The high-load-bearing support roller forming process according to claim 1, characterized in that: The alloy structural steel is a medium-carbon alloy steel with a carbon content of 0.45% to 0.55%. The chemical composition of the steel contains composite microalloying elements, including at least one of niobium (Nb) at a mass fraction of 0.02% to 0.05% and vanadium (V) at a mass fraction of 0.05% to 0.12%.

4. The high-load-bearing support roller forming process according to claim 1, characterized in that: The contour induction hardening device includes a main body, a control and processing box, a hardening treatment structure, a spraying device, a workpiece placement platform, and a hardening auxiliary cleaning mechanism. The control and processing box is installed on the surface of the main body. The hardening treatment structure is electrically connected to the control and processing box. The hardening treatment structure includes a large induction section corresponding to the end of the support roller and a small induction section corresponding to the other side of the support roller. The small induction section and the large induction section, when enclosed, are consistent with the structure of the support roller. The spraying device is located below the small induction section and the large induction section. The workpiece placement platform is axially collinear with the spraying device and the hardening treatment structure. The hardening auxiliary cleaning mechanism is located inside the main body of the device.

5. The high-load-bearing support roller forming process according to claim 4, characterized in that: The quenching structure includes a mounting plate and two symmetrically arranged processing units. The mounting plate has a lifting rod on its surface, and a connecting plate is mounted on the lifting rod. The other end of the connecting plate is connected to the large induction section with a heat-conducting strip. The surface of each processing unit is equipped with a heat-conducting plate and a telescopic drive component. The telescopic end of the telescopic drive component is connected to the small induction section with a connecting component. The small induction section is connected to the processing unit through a heat-conducting strip.

6. The high-load-bearing support roller forming process according to claim 1, characterized in that: In step S2, the three quenching media are supplied independently and switched sequentially through a spraying device, with the switching time between adjacent media not exceeding 0.5s. The spraying device includes a spraying frame, inside which are three equally spaced flow chambers. Water inlet pipes are symmetrically installed on the surface of the spraying frame. The water inlet pipes are arranged in groups of three, and each water inlet pipe is connected to one of the three flow chambers. Spraying pipes are arranged in a uniform array around the inner wall of the spraying frame, communicating with each flow chamber.

7. The high-load-bearing support roller forming process according to claim 6, characterized in that: The water outlet of each spray pipe is equipped with a fan-shaped spray plate. The three sets of spray pipes, corresponding to different quenching media, have their fan-shaped spray plates installed differently in a vertical and horizontal staggered arrangement to achieve uniform cooling of the entire support roller.

8. The high-load-bearing support roller forming process according to claim 4, characterized in that: The quenching auxiliary cleaning mechanism includes a receiving plate, a waste chip conveying assembly, a centralized collection frame, a waste chip lifting assembly, a scraper, and a drive frame. The receiving plate adopts a hollow filter screen structure. The waste chip conveying assembly is installed at the edge of the receiving plate. The discharge end of the waste chip conveying assembly is connected to the centralized collection frame. The waste chip lifting assembly is assembled on the outside of the centralized collection frame for directional discharge of waste residue. The scraper is installed at the output end of the receiving plate for scraping off and collecting quenching waste residue and oxide scale. The waste conveying assembly and the waste lifting assembly have the same structure, both consisting of a mesh conveyor plate and a drive motor; The drive frame integrates a hydraulic push rod, which drives the scraper to perform reciprocating linear motion.

9. The high-load-bearing support roller forming process according to claim 8, characterized in that: The scraping component includes a movable plate, a scraper, a cleaning strip, and a flexible pusher. The scraper has a triangular structure and is fixed to the bottom of the movable plate as an integral structure. The cleaning strip is detachably assembled to the lower surface of the movable plate and fits against the rear side of the scraper. Two sets of movable plates are symmetrically arranged, and the two sets of movable plates are respectively connected to the hydraulic push rod inside the drive frame. Flexible pushers are fixed to the opposite ends of the two sets of movable plates.

10. The high-load-bearing support roller forming process according to claim 8, characterized in that: The waste conveying assembly also includes an adjustable scraper, which is installed at one end of the waste conveying assembly near the centralized collection frame.

Images