High-temperature tempering process of spring for shock absorber

Abstract

The invention discloses a shock absorber spring manufacturing technology, and aims to provide a high-temperature tempering process of a shock absorber spring, and the technical scheme is that the high-temperature tempering process comprises the following steps: S1, preparing materials; s2, primary processing; s3, spring forming; s4, annealing for the first time; s5, heating to a tempering temperature; s6, high-temperature tempering; s7, cooling treatment; s8, tempering for the second time; s9, surface treatment; s10, annealing for the second time; s11, carrying out quality detection; and S12, final inspection and packaging. According to the high-temperature tempering process of the spring for the shock absorber, through fine treatment of multiple links, the comprehensive performance of the spring is effectively improved; firstly, the stability of alloy steel in a high-temperature environment is ensured through material selection, the high-temperature resistance and fatigue resistance of the spring are improved, the size precision and surface quality of the spring are ensured through the steps of primary machining, spring forming and the like, and the risk that the function of the spring is affected due to a rough surface or a size error is avoided; the method is suitable for the technical field of damper spring manufacturing.

Description

Technical Field

[0001] The present invention relates to a shock absorber spring manufacturing technology, and more specifically, it relates to a high temperature tempering process for a shock absorber spring. Background Art

[0002] As a key component in the shock absorption system, the shock absorber spring is required to have high strength, fatigue resistance, high temperature resistance and other properties.

[0003] In the prior art, the tempering process is generally used in the manufacturing process of springs, but the existing tempering method has certain defects in precision, efficiency, and optimization of material properties. Therefore, it is necessary to improve the tempering process, especially for improving the performance of shock absorber springs in high temperature environments. Summary of the invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide a high-performance high-temperature tempering process for a shock absorber spring.

[0005] To achieve the above object, the present invention provides the following technical solution: a high temperature tempering process for a spring for a shock absorber, comprising the following steps:

[0006] S1. Material preparation: Select high-strength alloy steel materials suitable for shock absorber springs, including but not limited to carbon steel, stainless steel or alloy steel; the specifications of the selected materials are 6mm-12mm in diameter and 5mm-20mm in length, depending on the specific application requirements;

[0007] S2. Primary processing: hot rolling or cold rolling of the selected materials to ensure that the surface is flat and meets the specification requirements. The steel after primary processing needs to be rust-removed and cleaned to remove surface impurities and oxide layers to ensure the processing quality of the spring;

[0008] S3. Spring forming: The pre-processed steel is cold-formed or hot-formed according to the required spring shape. According to the spring diameter, length and number of turns, the winding and shearing process is carried out by precise CNC equipment, and the dimensional accuracy of the formed spring is tested to ensure that it meets the design requirements;

[0009] S4, first annealing: The formed spring needs to be annealed for the first time. The formed spring is heated to 550℃-650℃, the heat preservation time is 60min-120min, and then slowly cooled to room temperature to remove the internal stress of the spring and improve its subsequent tempering performance;

[0010] S5. Heating to tempering temperature: Place the annealed spring in a tempering furnace and gradually heat it to 850°C-950°C, with a heating rate of 2°C-5°C per minute to ensure uniform temperature rise and prevent material deformation or damage caused by over-rapid heating;

[0011] S6, high temperature tempering: when the temperature reaches 850℃-950℃, maintain this high temperature environment for 30min-60min. During this process, the grain of the steel is refined, the internal structure of the spring is optimized, and its high temperature resistance and fatigue resistance are significantly improved;

[0012] S7. Cooling treatment: After high-temperature tempering, take the spring out of the tempering furnace and quickly cool it to room temperature. The cooling method is natural air cooling or oil quenching to ensure that its surface hardness and internal toughness are balanced.

[0013] S8, Second tempering: In order to further improve the comprehensive performance of the spring, the second tempering treatment is carried out. The cooled spring is heated again to 300℃-400℃, kept for 10min-20min, and then naturally cooled to room temperature, which helps to optimize the durability of the spring;

[0014] S9. Surface treatment: Surface treatment of the spring after tempering, including but not limited to galvanizing, phosphating, sandblasting, carburizing, coating, to ensure that the surface of the spring is smooth and flawless and improve its corrosion resistance;

[0015] S10, Second annealing: low temperature annealing is performed on the spring that has completed the surface treatment, the annealing temperature is 200℃-300℃, and the holding time is 30min-60min, to ensure further elimination of internal stress and improve the plasticity of the spring;

[0016] S11. Quality inspection: Strict quality inspection is carried out on each batch of processed springs. The inspection contents include but are not limited to hardness, toughness, fatigue life, and dimensional accuracy to ensure that the springs meet the design requirements;

[0017] S12. Final inspection and packaging: The springs that have passed the inspection are subject to final inspection to ensure that their appearance and performance meet the design requirements. The springs that have passed the inspection are packaged and marked and sent to the warehouse or directly to the customer.

[0018] The present invention is further configured as follows: the tempering furnace used in the high-temperature tempering is an atmosphere-controlled furnace, and the atmosphere in the furnace is protected by nitrogen or argon to prevent oxidation of the spring surface.

[0019] The present invention is further configured as follows: the cooling treatment method is oil quenching and air cooling alternately, wherein the oil quenching time is 10s-30s, and the air cooling time is 30s-60s, so as to ensure that the spring hardness is uniform and does not deform.

[0020] The present invention is further configured such that the temperature change rate during the cooling process of the cooling treatment is controlled at ≤30°C / min to reduce structural damage to the spring caused by temperature differences.

[0021] The present invention is further configured as follows: the coating in the surface treatment process is a PTFE coating, the coating thickness is 0.05mm-0.1mm, and the coating can improve the corrosion resistance of the spring and reduce the friction coefficient.

[0022] The present invention is further configured as follows: after the second tempering, the hardness value is tested by a Rockwell hardness test method to ensure that the hardness of the spring is between 35HRC and 45HRC; after the second annealing, the tensile strength of the spring is increased by 10% to 15%.

[0023] The present invention is further configured as follows: the steel selected in the material preparation is alloy steel, and the composition ratio of the alloy steel is: carbon: 0.4%-0.8%, chromium: 0.5%-1.0%, manganese: 0.5%-1.5%, silicon: 0.1%-0.3%, aluminum: 0.02%-0.05%, vanadium: 0.01%-0.1%, and molybdenum: 0.1%-0.3%.

[0024] The beneficial effects of the present invention are:

[0025] 1. Compared with the prior art, the high-temperature tempering process of the spring for shock absorber of the present invention effectively improves the comprehensive performance of the spring through the fine processing of multiple links; first, the selection of materials ensures the stability of alloy steel in high temperature environment, improves the high temperature resistance and fatigue resistance of the spring, and the steps of initial processing, spring forming and other steps ensure the dimensional accuracy and surface quality of the spring, avoiding the risk of affecting the function of the spring due to rough surface or dimensional error; through two annealing treatments, not only can the internal stress be effectively removed, but also the microstructure of the spring can be optimized, and its elasticity and toughness can be improved; during the high-temperature tempering process, precise heating and temperature holding time ensure the refinement of the internal grains of the spring, thereby enhancing the strength and durability of the spring; in addition, the surface treatment step enhances the corrosion resistance of the spring and improves its service life; the combination of the second tempering and low-temperature annealing balances the hardness and plasticity of the spring, ensuring that the spring will not be excessively brittle or fatigue failure during long-term use.

[0026] 2. The high-temperature tempering process of the shock absorber spring of the present invention adopts an atmosphere-controlled furnace for high-temperature tempering, which prevents the oxidation problem caused by the reaction of oxygen in the air with the metal at high temperature in the traditional tempering process, keeps the spring surface smooth and flawless, and avoids the formation of an oxide layer, ensuring the surface quality and performance stability of the spring. At the same time, the use of an atmosphere-controlled furnace can also improve the temperature control accuracy during the tempering process, ensure uniform temperature inside and outside the spring, further improve the tempering effect, and optimize the microstructure of the spring. This technology can greatly reduce surface defects on the spring and effectively improve the corrosion resistance of the spring.

[0027] 3. In the present invention, the alternating method of oil quenching and air cooling enables the spring to quickly and effectively reduce the temperature during the cooling process, avoiding temperature differences and stress concentration on the surface or inside of the spring caused by inconsistent cooling speed. This treatment method can not only ensure that the hardness of the spring meets the design requirements, but also effectively reduce the cracks and deformation problems caused by uneven cooling. The rapid cooling of oil quenching is combined with the slow cooling of air cooling, so that the spring can avoid the brittleness caused by rapid cooling while ensuring the hardness, thereby improving the comprehensive performance of the spring and enhancing its reliability in use.

[0028] 4. In the present invention, too fast or too slow cooling speed will have adverse effects on the internal and external structures of the spring, which may cause problems such as breakage and deformation of the spring during use. By strictly controlling the cooling rate, not only can the internal stress concentration caused by excessive temperature difference be avoided, but also the microstructure of the spring can be ensured to be more uniform, and its fatigue resistance and durability can be improved. The optimization of this cooling process can effectively improve the quality and service life of the spring, and is particularly suitable for shock absorber springs that require high precision and high performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flowchart of the high temperature tempering process of the shock absorber spring. DETAILED DESCRIPTION

[0030] Reference Figure 1 The high temperature tempering process embodiment of the shock absorber spring of the present invention is further described.

[0031] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0032] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0033] Figure 1 A high temperature tempering process for a spring for a shock absorber is shown, comprising the following steps:

[0034] S1. Material preparation: Select high-strength alloy steel materials suitable for shock absorber springs, including but not limited to carbon steel, stainless steel or alloy steel; the specifications of the selected materials are 6mm-12mm in diameter and 5mm-20mm in length, depending on the specific application requirements;

[0035] S2. Primary processing: hot rolling or cold rolling of the selected materials to ensure that the surface is flat and meets the specification requirements. The steel after primary processing needs to be rust-removed and cleaned to remove surface impurities and oxide layers to ensure the processing quality of the spring;

[0036] S3. Spring forming: The pre-processed steel is cold-formed or hot-formed according to the required spring shape. According to the spring diameter, length and number of turns, the winding and shearing process is carried out by precise CNC equipment, and the dimensional accuracy of the formed spring is tested to ensure that it meets the design requirements;

[0037] S4, first annealing: The formed spring needs to be annealed for the first time. The formed spring is heated to 550℃-650℃, the heat preservation time is 60min-120min, and then slowly cooled to room temperature to remove the internal stress of the spring and improve its subsequent tempering performance;

[0038] S5. Heating to tempering temperature: Place the annealed spring in a tempering furnace and gradually heat it to 850°C-950°C, with a heating rate of 2°C-5°C per minute to ensure uniform temperature rise and prevent material deformation or damage caused by over-rapid heating;

[0039] S6, high temperature tempering: when the temperature reaches 850℃-950℃, maintain this high temperature environment for 30min-60min. During this process, the grain of the steel is refined, the internal structure of the spring is optimized, and its high temperature resistance and fatigue resistance are significantly improved;

[0040] S7. Cooling treatment: After high-temperature tempering, take the spring out of the tempering furnace and quickly cool it to room temperature. The cooling method is natural air cooling or oil quenching to ensure that its surface hardness and internal toughness are balanced.

[0041] S8, Second tempering: In order to further improve the comprehensive performance of the spring, the second tempering treatment is carried out. The cooled spring is heated again to 300℃-400℃, kept for 10min-20min, and then naturally cooled to room temperature, which helps to optimize the durability of the spring;

[0042] S9. Surface treatment: Surface treatment is performed on the spring after tempering, including but not limited to galvanizing, phosphating, sandblasting, carburizing, and coating to ensure that the surface of the spring is smooth and flawless and improve its corrosion resistance;

[0043] S10, Second annealing: low temperature annealing is performed on the spring that has completed the surface treatment, the annealing temperature is 200℃-300℃, and the holding time is 30min-60min, to ensure further elimination of internal stress and improve the plasticity of the spring;

[0044] S11. Quality inspection: Strict quality inspection is carried out on each batch of processed springs. The inspection contents include but are not limited to hardness, toughness, fatigue life, and dimensional accuracy to ensure that the springs meet the design requirements;

[0045] S12. Final inspection and packaging: Conduct final inspection on the springs that have passed the inspection to ensure that their appearance and performance meet the design requirements. The springs that have passed the inspection will be packaged and marked and sent to the warehouse or directly to the customer;

[0046] Compared with the prior art, the high-temperature tempering process of the spring for shock absorber of the present invention effectively improves the comprehensive performance of the spring through the fine processing of multiple links; first, the selection of materials ensures the stability of alloy steel in high temperature environment, improves the high temperature resistance and fatigue resistance of the spring, and the initial processing, spring forming and other steps ensure the dimensional accuracy and surface quality of the spring, avoiding the risk of affecting the spring function due to rough surface or dimensional error; through two annealing treatments, not only can the internal stress be effectively removed, but also the microstructure of the spring can be optimized to improve its elasticity and toughness; during the high-temperature tempering process, precise heating and temperature holding time ensure the refinement of the internal grains of the spring, thereby enhancing the strength and durability of the spring; in addition, the surface treatment step enhances the corrosion resistance of the spring and improves its service life; the combination of the second tempering and low-temperature annealing balances the hardness and plasticity of the spring, ensuring that the spring will not be excessively brittle or fatigue failure during long-term use.

[0047] The tempering furnace used in the high temperature tempering is an atmosphere controlled furnace, and the atmosphere in the furnace is protected by nitrogen or argon to prevent oxidation of the spring surface;

[0048] The use of an atmosphere-controlled furnace for high-temperature tempering prevents oxidation problems caused by the reaction of oxygen in the air with metal at high temperatures during the traditional tempering process, keeps the spring surface smooth and flawless, and avoids the formation of an oxide layer, ensuring the surface quality and performance stability of the spring. At the same time, the use of an atmosphere-controlled furnace can also improve the temperature control accuracy during the tempering process, ensure uniform temperature inside and outside the spring, further improve the tempering effect, and optimize the microstructure of the spring. This technology can greatly reduce surface defects on the spring and effectively improve the corrosion resistance of the spring.

[0049] The cooling treatment method is oil quenching and air cooling alternately, wherein the oil quenching time is 10s-30s, and the air cooling time is 30s-60s, so as to ensure that the spring hardness is uniform and does not deform;

[0050] The alternating method of oil quenching and air cooling enables the spring to quickly and effectively reduce the temperature during the cooling process, avoiding temperature differences and stress concentration on the surface or inside of the spring caused by inconsistent cooling speed. This treatment method can not only ensure that the hardness of the spring meets the design requirements, but also effectively reduce the cracks and deformation problems caused by uneven cooling. The combination of rapid cooling of oil quenching and slow cooling of air cooling ensures the hardness of the spring while avoiding the brittleness caused by rapid cooling, thereby improving the comprehensive performance of the spring and enhancing its reliability in use.

[0051] The temperature change rate during the cooling process of the cooling treatment is controlled at ≤30°C / min to reduce structural damage to the spring caused by temperature differences;

[0052] Too fast or too slow cooling speed will have adverse effects on the internal and external structures of the spring, and may cause problems such as breakage and deformation of the spring during use. By strictly controlling the cooling rate, not only can the internal stress concentration caused by excessive temperature difference be avoided, but also the microstructure of the spring can be ensured to be more uniform, thereby improving its fatigue resistance and durability. This optimization of the cooling process can effectively improve the quality and service life of the spring, and is especially suitable for shock absorber springs that require high precision and high performance.

[0053] The coating in the surface treatment process is a PTFE coating with a coating thickness of 0.05 mm to 0.1 mm. The coating can improve the corrosion resistance of the spring and reduce the friction coefficient;

[0054] The surface treatment process of applying PTFE coating can significantly improve the corrosion resistance of the spring and reduce the friction coefficient. PTFE (polytetrafluoroethylene) coating has excellent chemical stability and low friction characteristics, which can effectively protect the surface of the spring from corrosive substances, thereby extending the service life of the spring, especially when used in a humid or corrosive environment. At the same time, the presence of the coating can also reduce the friction between the spring and other components during operation, reduce energy loss, and improve the shock absorption effect. The coating thickness is controlled between 0.05mm-0.1mm, which can not only ensure the effectiveness of the coating, but also will not have too much impact on the size and shape of the spring, thereby comprehensively improving the performance of the spring.

[0055] After the second tempering, the hardness value is tested by Rockwell hardness test method to ensure that the hardness of the spring is 35HRC-45HRC; after the second annealing, the tensile strength of the spring is increased by 10%-15%;

[0056] By testing the hardness value through the Rockwell hardness test method and ensuring that the spring hardness is between 35HRC-45HRC, the balance between the strength and toughness of the spring can be effectively guaranteed. The hardness value after the second tempering is in line with this range, which helps to improve the fatigue resistance and wear resistance of the spring and adapt to high-frequency workloads and long-term use requirements. At the same time, the tensile strength after the second annealing is increased by 10%-15%, which further improves the tensile properties of the spring and enhances its adaptability in high-stress environments. These measures help to ensure the stability and reliability of the spring under various harsh working conditions, thereby improving the overall performance of the shock absorber.

[0057] The steel selected in the material preparation is alloy steel, and the composition ratio of the alloy steel is: carbon: 0.4%-0.8%, chromium: 0.5%-1.0%, manganese: 0.5%-1.5%, silicon: 0.1%-0.3%, aluminum: 0.02%-0.05%, vanadium: 0.01%-0.1%, molybdenum: 0.1%-0.3%;

[0058] The selection of alloy steel as the material and precise control of its composition ratio can greatly improve the mechanical properties of the spring. The reasonable proportion design of the main components of alloy steel such as carbon, chromium, manganese, silicon, aluminum, vanadium and molybdenum can enhance the spring's resistance to high temperature, oxidation and fatigue, while improving its strength and hardness. Reasonable control of carbon content ensures the strength and hardness of the steel. The addition of chromium and molybdenum effectively enhances the corrosion resistance of the steel. The addition of vanadium improves the toughness of the steel, ensuring that the spring is not easy to break when subjected to heavy loads. By optimizing the alloy composition, this process can produce shock absorber springs with excellent mechanical properties and long-term durability to meet high-strength and high-performance application requirements.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A high temperature tempering process for a spring for a shock absorber, characterized in that: The following steps are involved: S1. Material preparation: Select high-strength alloy steel materials suitable for shock absorber springs, including but not limited to carbon steel, stainless steel or alloy steel; the specifications of the selected materials are 6mm-12mm in diameter and 5mm-20mm in length, depending on the specific application requirements; S2. Primary processing: hot rolling or cold rolling of the selected materials to ensure that the surface is flat and meets the specification requirements. The steel after primary processing needs to be rust-removed and cleaned to remove surface impurities and oxide layers to ensure the processing quality of the spring; S3. Spring forming: The pre-processed steel is cold-formed or hot-formed according to the required spring shape. According to the spring diameter, length and number of turns, the winding and shearing process is carried out by precise CNC equipment, and the dimensional accuracy of the formed spring is tested to ensure that it meets the design requirements; S4, first annealing: The formed spring needs to be annealed for the first time. The formed spring is heated to 550℃-650℃, the heat preservation time is 60min-120min, and then slowly cooled to room temperature to remove the internal stress of the spring and improve its subsequent tempering performance; S5. Heating to tempering temperature: Place the annealed spring in a tempering furnace and gradually heat it to 850°C-950°C, with a heating rate of 2°C-5°C per minute to ensure uniform temperature rise and prevent material deformation or damage caused by over-rapid heating; S6, high temperature tempering: when the temperature reaches 850℃-950℃, maintain this high temperature environment for 30min-60min. During this process, the grain of the steel is refined, the internal structure of the spring is optimized, and its high temperature resistance and fatigue resistance are significantly improved; S7. Cooling treatment: After high-temperature tempering, take the spring out of the tempering furnace and quickly cool it to room temperature. The cooling method is natural air cooling or oil quenching to ensure that its surface hardness and internal toughness are balanced. S8, Second tempering: In order to further improve the comprehensive performance of the spring, the second tempering treatment is carried out. The cooled spring is heated again to 300℃-400℃, kept for 10min-20min, and then naturally cooled to room temperature, which helps to optimize the durability of the spring; S9. Surface treatment: Surface treatment of the spring after tempering, including but not limited to galvanizing, phosphating, sandblasting, carburizing, coating, to ensure that the surface of the spring is smooth and flawless and improve its corrosion resistance; S10, Second annealing: low temperature annealing is performed on the spring that has completed the surface treatment, the annealing temperature is 200℃-300℃, and the holding time is 30min-60min, to ensure further elimination of internal stress and improve the plasticity of the spring; S11. Quality inspection: Strict quality inspection is carried out on each batch of processed springs. The inspection contents include but are not limited to hardness, toughness, fatigue life, and dimensional accuracy to ensure that the springs meet the design requirements; S12. Final inspection and packaging: The springs that have passed the inspection are subject to final inspection to ensure that their appearance and performance meet the design requirements. The springs that have passed the inspection are packaged and marked and sent to the warehouse or directly to the customer.

2. A high temperature tempering process for a shock absorber spring according to claim 1, characterized in that: The tempering furnace used in the high temperature tempering is an atmosphere controlled furnace, and the atmosphere in the furnace is protected by nitrogen or argon to prevent oxidation of the spring surface.

3. The high temperature tempering process for a shock absorber spring according to claim 1, characterized in that: The cooling treatment method is to perform oil quenching and air cooling alternately, wherein the oil quenching time is 10s-30s, and the air cooling time is 30s-60s, so as to ensure that the spring hardness is uniform and does not deform.

4. A high temperature tempering process for a shock absorber spring according to claim 3, characterized in that: The temperature change rate during the cooling process of the cooling treatment is controlled at ≤30°C / min to reduce structural damage to the spring caused by temperature differences.

5. The high temperature tempering process for a shock absorber spring according to claim 1, characterized in that: The coating in the surface treatment process is a PTFE coating with a thickness of 0.05 mm to 0.1 mm. The coating can improve the corrosion resistance of the spring and reduce the friction coefficient.

6. The high temperature tempering process for a shock absorber spring according to claim 1, characterized in that: After the second tempering, the hardness value is tested by Rockwell hardness test method to ensure that the hardness of the spring is 35HRC-45HRC; after the second annealing, the tensile strength of the spring is increased by 10%-15%.

7. The high temperature tempering process for a shock absorber spring according to claim 1, characterized in that: The steel material selected in the material preparation is alloy steel, and the composition ratio of the alloy steel is: carbon: 0.4%-0.8%, chromium: 0.5%-1.0%, manganese: 0.5%-1.5%, silicon: 0.1%-0.3%, aluminum: 0.02%-0.05%, vanadium: 0.01%-0.1%, and molybdenum: 0.1%-0.3%.

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