Machining process of spring for shock absorber

Abstract

The invention discloses a shock absorber spring technology, and aims to provide a machining process of a shock absorber spring, and the technical scheme is characterized by comprising the following steps: S1, material selection and pretreatment; s2, cutting the raw materials; s3, stretching and heat treatment of the raw materials; s4, cold forming; s5, surface treatment and anti-corrosion treatment; s6, heat treatment and tempering; s7, carrying out size correction and straightening; s8, inspection and quality control; and S9, packaging and delivery inspection. Compared with the prior art, the processing technology of the spring for the shock absorber has the advantages that each step from raw material selection to final packaging and delivery inspection is strictly controlled, so that high quality and high performance of the spring are ensured; the damper is suitable for the technical field of dampers.

Description

Technical Field

[0001] The present invention relates to a shock absorber spring technology, and more specifically, to a processing technology for a shock absorber spring. Background Art

[0002] Spring shock absorbers are widely used in shock absorption systems of automobiles, motorcycles, engineering machinery and other equipment. Their main function is to absorb and reduce vibrations to maintain the smooth operation of the equipment. Most of the existing spring shock absorbers use ordinary springs, but due to improper spring production process and material selection, they are prone to problems such as insufficient spring performance, poor durability, poor fatigue resistance, etc., resulting in shock absorber failure or short service life. Therefore, there is an urgent need for a new processing technology that can improve the performance of the spring and ensure that it still maintains a good shock absorption effect under high-intensity and high-frequency use. Summary of the invention

[0003] In view of the deficiencies in the prior art, the object of the present invention is to provide a high-quality and high-performance processing technology for a shock absorber spring.

[0004] To achieve the above object, the present invention provides the following technical solution: a processing technology for a spring for a shock absorber, comprising the following steps: S1. Material selection and pretreatment: Select high-strength alloy steel or stainless steel as raw material, requiring its yield strength to be no less than 600MPa, tensile strength to be no less than 1000MPa, and excellent elastic recovery; the chemical composition of alloy steel includes but is not limited to C: 0.7%-0.9%, Si: 0.2%-0.3%, Mn: 0.5%-0.8%, Cr: 0.5%-0.7%, Ni: 0.3%-0.5%, Mo: 0.2%-0.3%; degrease and rust the selected steel, use pickling process to remove surface oxides to ensure the cleanliness of the steel surface, and use sandblasting to further clean impurities; S2. Raw material cutting: Use CNC cutting equipment to cut the raw materials to ensure that the length of the cut material meets the design requirements of the spring; S3. Stretching and heat treatment of raw materials: The treated steel is stretched to adjust the initial size of the steel to meet the design requirements of the spring. After stretching, high-temperature annealing is performed. The annealing temperature is controlled within the range of 550℃-600℃. The duration is adjusted according to the diameter and length of the steel. After annealing, the grains of the steel are homogenized to improve its plasticity and strength. S4, cold forming: the annealed steel is sent to the CNC spring forming machine for precise spring forming. According to the design requirements of the spring, the tension, pressure and rotation angle of the forming machine are adjusted to make the steel be wound according to the predetermined shape, and ensure that the wire diameter, inner diameter and outer diameter of each circle are uniform; S5. Surface treatment and anti-corrosion treatment: The spring after forming needs to be surface hardened and anti-corrosion treated. First, the surface is phosphated to increase the adhesion of the coating, and an anti-corrosion nickel-chromium alloy layer is plated on the surface of the spring by electroplating. The thickness of the coating is controlled at 5μm-15μm, so that the hardness range of the spring surface is 60HRC-65HRC. S6. Heat treatment and tempering: Carburizing is used to heat treat the formed springs. The carburizing temperature is controlled at 900℃-950℃. The carburizing time is adjusted according to the size of the springs. After carburizing, tempering is performed. The tempering temperature is controlled at 200℃-250℃. The overall hardness range of the spring after heat treatment and tempering is 45HRC-55HRC, so that the hardness and toughness of the springs reach the best balance to avoid brittle fracture during use. S7. Dimension correction and straightening: Use an automatic straightening machine to correct the size of the formed spring to ensure that the straightness and shape of the spring are not deformed. After straightening, check the shape and size of the spring to confirm that it meets the design requirements. Use a laser measuring instrument to detect the various dimensions of the spring to ensure that its accuracy is within 0.1mm; S8. Inspection and quality control: Strict quality inspection is carried out on each batch of springs produced to ensure that all products meet the standards; S9. Packaging and factory inspection: Finally, all qualified springs will be marked and packaged according to customer requirements and undergo final factory inspection; factory inspection includes appearance inspection, packaging inspection, and random sampling of samples for tensile strength and fatigue testing to ensure that each batch of products can meet the use requirements.

[0005] The present invention is further configured as follows: in the S1, the alloy steel adopts a special alloying composition, wherein the C content is 0.8%, the Mn content is 0.6%, the Cr content is 0.6%, the Mo content is 0.25%, and the V content is 0.2%, so as to improve the fatigue resistance and corrosion resistance of the spring.

[0006] The present invention is further configured as follows: in S3, annealing is performed in a protective atmosphere, using nitrogen or argon as a protective gas to avoid oxidation of the steel surface and improve the surface quality.

[0007] The present invention is further configured as follows: in S4, the forming speed of the CNC spring forming machine is controlled at ≤1000r / min, and the number of coils and tension of the spring are adjusted in real time.

[0008] The present invention is further configured as follows: in S5, the electroplating process includes nickel electroplating and chromium electroplating, and the thickness of the electroplating layer is 6 μm and 8 μm respectively, so as to enhance its corrosion resistance.

[0009] The present invention is further configured as follows: in S6, the carburizing treatment adopts a gas carburizing method, the carburizing atmosphere contains 10%-15% methane, the temperature is 930° C., and the carburizing time is 3 hours.

[0010] The present invention is further configured as follows: in S7, dimension correction and straightening are performed by combining a laser scanner and an automatic straightening machine to ensure the geometrical dimension and shape accuracy of the spring.

[0011] The present invention is further configured as follows: in S9, the factory inspection adopts an air tightness test and a static strength test to ensure the performance stability and safety of the spring when used in the shock absorber.

[0012] The present invention is further configured as follows: in S8, the quality inspection includes: S81, Dimensional accuracy inspection: S811. Use a high-precision three-dimensional measuring machine to measure the dimensions of each spring in all directions, including but not limited to the outer diameter, inner diameter and free height of the spring; the measurement error is ±0.1mm; for mass production, at least 5% of each batch of products must be randomly sampled for inspection to ensure that they meet the design requirements; S812. Check the number of spiral turns of each spring to ensure that it is consistent with the number of turns in the design requirements; if the error is found to exceed the set tolerance range, the spring will be scrapped and the production process will need to be adjusted; S82, surface quality inspection: S821. Use a surface finish tester to test the surface finish of the spring, and the surface roughness value is less than 0.8μm; S822. Test the coating of the spring and use an electronic probe analyzer to accurately measure the thickness of the coating to ensure that the thickness of the coating meets the standard requirements; S83, hardness and strength test: S831. Use Rockwell hardness tester to test the surface hardness of the spring to ensure that the hardness meets the design requirements; S832. Use a tensile testing machine to test the tensile strength of the spring to ensure that its tensile strength meets the requirements. The tensile speed of the tensile test is controlled at 5 mm / min. S84, fatigue life test: S841. Use a fatigue testing machine to test the durability of the spring. Repeated loading and unloading is used to simulate the load of the spring in actual shock absorber use. The loading frequency is 5 Hz, the maximum load is 1.3-1.5 times the rated load of the spring, and at least 100,000 cycles of loading are performed. S842. Evaluate the fatigue life of the spring by monitoring any cracks or signs of failure during the test, and adjust the tension and shape of the spring appropriately based on the test results to ensure that it has excellent elasticity and durability under normal use; S85, Anti-corrosion Performance Test: S851, Salt spray test: Use neutral salt spray test standard to test the anti-corrosion performance of the spring. The test duration is 48 hours to ensure that there is no obvious rust or corrosion on the spring surface. S852, Sodium chloride solution immersion test: Soak the spring in 5% sodium chloride solution for 48 hours, and then check the integrity of the coating and surface corrosion.

[0013] The beneficial effects of the present invention are: 1. Compared with the prior art, the processing technology of the spring for shock absorber of the present invention is strictly controlled in each step from the selection of raw materials to the final packaging and factory inspection, ensuring the high quality and high performance of the spring; by selecting high-strength alloy steel or stainless steel with excellent elastic recovery, the durability and high load bearing capacity of the spring in long-term use are ensured; at the same time, pretreatment processes such as pickling and sandblasting can effectively remove surface impurities, reduce defects in subsequent processing, and improve the surface quality of the final spring; through precise CNC cutting, stretching and heat treatment processes, the geometric dimensions and mechanical properties of the spring are ensured, and failure caused by uneven materials or poor molding is avoided; in addition, the spring that has undergone multiple surface treatments such as electroplating and carburizing has strong corrosion resistance and fatigue life, and can cope with frequent impacts and vibrations during the operation of the shock absorber; furthermore, through precise dimensional correction and straightening, the straightness and shape stability of the spring are ensured, and the safety and reliability of its working process are improved; finally, strict quality inspection is performed to ensure that the produced spring meets the design requirements.

[0014] 2. The alloy steel in the processing technology of the spring for shock absorber of the present invention adopts specific alloying components. The C element improves the hardness and strength of the steel, while the Mn element can enhance the toughness of the steel and avoid damage caused by brittle fracture. The addition of Cr and Mo effectively improves the anti-oxidation and anti-corrosion capabilities of the steel, and can maintain good working performance in harsh environments. The addition of the V element helps to refine the grains of the steel, improve the fatigue resistance of the steel, and extend the service life of the spring. These optimized chemical composition combinations enable the final spring to maintain stable performance in the high-frequency and high-pressure environment of the shock absorber, reduce failures caused by factors such as fatigue and corrosion, and provide a longer service life.

[0015] 3. In the present invention, the advantage of using protective atmosphere annealing is that it can effectively avoid oxidation damage in the traditional annealing process, ensuring that the surface of the spring remains smooth, uniform and free of cracks. At the same time, the use of protective atmosphere improves the control accuracy of the annealing process, so that the steel maintains better structural stability during the annealing process, further improving the toughness and strength of the steel. Through the protective atmosphere annealing technology, the grain structure of the steel can be optimized, making it easier to deform during the forming process, reducing the risk of cracks in the forming process.

[0016] 4. In the present invention, the quality inspection procedure includes dimensional accuracy inspection, surface quality inspection, hardness and strength inspection, fatigue life inspection and anti-corrosion performance inspection; dimensional accuracy inspection can ensure that the geometric dimensions of the spring meet the design requirements, thereby avoiding incompatibility or unstable working performance caused by dimensional deviation; surface quality inspection ensures the surface finish of the spring and the integrity of the coating, avoiding fatigue cracks or corrosion problems caused by surface defects; hardness and strength inspection can verify whether the spring has excellent hardness and strength, ensuring that it will not deform or break due to excessive load during operation, thereby improving the service life and safety of the spring; fatigue life inspection simulates the repeated loading of the spring in actual use, predicts its durability and fatigue performance in long-term use, and reduces the risk of failure; anti-corrosion performance inspection can evaluate the corrosion resistance of the spring in a specific environment, avoid corrosion problems caused by the external environment, and ensure the long-term reliability and stability of the spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a flow chart of the processing technology of the spring for the shock absorber of the present invention.

[0018] Figure 2 It is a flow chart of quality inspection in the present invention. DETAILED DESCRIPTION

[0019] Reference Figure 1-2 The processing technology embodiment of the shock absorber spring of the present invention is further described.

[0020] 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.

[0021] 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.

[0022] Figure 1 to Figure 2 The processing technology of a spring for a shock absorber shown in the figure includes the following steps: S1. Material selection and pretreatment: Select high-strength alloy steel or stainless steel as raw material, requiring its yield strength to be no less than 600MPa, tensile strength to be no less than 1000MPa, and excellent elastic recovery; the chemical composition of alloy steel includes but is not limited to C: 0.7%-0.9%, Si: 0.2%-0.3%, Mn: 0.5%-0.8%, Cr: 0.5%-0.7%, Ni: 0.3%-0.5%, Mo: 0.2%-0.3%; degrease and rust the selected steel, use pickling process to remove surface oxides to ensure the cleanliness of the steel surface, and use sandblasting to further clean impurities; S2. Raw material cutting: Use CNC cutting equipment to cut the raw materials to ensure that the length of the cut material meets the design requirements of the spring; S3. Stretching and heat treatment of raw materials: The treated steel is stretched to adjust the initial size of the steel to meet the design requirements of the spring. After stretching, high-temperature annealing is performed. The annealing temperature is controlled within the range of 550℃-600℃. The duration is adjusted according to the diameter and length of the steel. After annealing, the grains of the steel are homogenized to improve its plasticity and strength. S4, cold forming: the annealed steel is sent to the CNC spring forming machine for precise spring forming. According to the design requirements of the spring, the tension, pressure and rotation angle of the forming machine are adjusted to make the steel be wound according to the predetermined shape, and ensure that the wire diameter, inner diameter and outer diameter of each circle are uniform; S5. Surface treatment and anti-corrosion treatment: The spring after forming needs to be surface hardened and anti-corrosion treated. First, the surface is phosphated to increase the adhesion of the coating, and an anti-corrosion nickel-chromium alloy layer is plated on the surface of the spring by electroplating. The thickness of the coating is controlled at 5μm-15μm, so that the hardness range of the spring surface is 60HRC-65HRC. S6. Heat treatment and tempering: Carburizing is used to heat treat the formed springs. The carburizing temperature is controlled at 900℃-950℃. The carburizing time is adjusted according to the size of the springs. After carburizing, tempering is performed. The tempering temperature is controlled at 200℃-250℃. The overall hardness range of the spring after heat treatment and tempering is 45HRC-55HRC, so that the hardness and toughness of the springs reach the best balance to avoid brittle fracture during use. S7. Dimension correction and straightening: Use an automatic straightening machine to correct the size of the formed spring to ensure that the straightness and shape of the spring are not deformed. After straightening, check the shape and size of the spring to confirm that it meets the design requirements. Use a laser measuring instrument to detect the various dimensions of the spring to ensure that its accuracy is within 0.1mm; S8. Inspection and quality control: Strict quality inspection is carried out on each batch of springs produced to ensure that all products meet the standards; S9, Packaging and factory inspection: Finally, all qualified springs will be marked, packaged and inspected according to customer requirements. The factory inspection includes appearance inspection, packaging inspection and random sampling of samples for tensile strength and fatigue testing to ensure that each batch of products can meet the use requirements. Compared with the prior art, the processing technology of the spring for shock absorber of the present invention is strictly controlled in each step from the selection of raw materials to the final packaging and factory inspection, thereby ensuring the high quality and high performance of the spring; by selecting high-strength alloy steel or stainless steel with excellent elastic recovery, the durability and high load bearing capacity of the spring in long-term use are ensured; at the same time, pretreatment processes such as pickling and sandblasting can effectively remove surface impurities, reduce defects in subsequent processing, and improve the surface quality of the final spring; through precise CNC cutting, stretching and heat treatment processes, the geometric dimensions and mechanical properties of the spring are ensured, and failure caused by uneven materials or poor molding is avoided; in addition, the spring that has undergone multiple surface treatments such as electroplating and carburizing has strong corrosion resistance and fatigue life, and can cope with frequent impacts and vibrations during the operation of the shock absorber; furthermore, through precise dimensional correction and straightening, the straightness and shape stability of the spring are ensured, and its safety and reliability during operation are improved; finally, strict quality inspection is performed to ensure that the produced spring meets the design requirements.

[0023] In the S1, the alloy steel adopts a special alloying composition, wherein the C content is 0.8%, the Mn content is 0.6%, the Cr content is 0.6%, the Mo content is 0.25%, and the V content is 0.2%, so as to improve the fatigue resistance and corrosion resistance of the spring; The alloy steel in the present invention adopts specific alloying components. The C element improves the hardness and strength of the steel, while the Mn element can enhance the toughness of the steel and avoid damage caused by brittle fracture. The addition of Cr and Mo effectively improves the oxidation resistance and corrosion resistance of the steel, and can maintain good working performance in harsh environments. The addition of the V element helps to refine the grains of the steel, improve the fatigue resistance of the steel, and extend the service life of the spring. These optimized chemical composition combinations enable the final spring to maintain stable performance in the high-frequency and high-pressure environment of the shock absorber, reduce failures caused by factors such as fatigue and corrosion, and provide a longer service life.

[0024] In S3, annealing is performed in a protective atmosphere, using nitrogen or argon as a protective gas to avoid oxidation of the steel surface and improve the surface quality; The advantage of this process in the present invention is that it can effectively avoid oxidation damage in the traditional annealing process, ensuring that the surface of the spring remains smooth, uniform and free of cracks. At the same time, the use of a protective atmosphere improves the control accuracy of the annealing process, allowing the steel to maintain better structural stability during the annealing process, further improving the toughness and strength of the steel. Through the protective atmosphere annealing technology, the grain structure of the steel can be optimized, making it easier to deform during the forming process, reducing the risk of cracks occurring during the forming process.

[0025] In S4, the forming speed of the CNC spring forming machine is controlled at ≤1000r / min, and the number of coils and tension of the spring are adjusted in real time; This technical solution ensures that the forming speed is strictly controlled during the spring forming process, avoiding uneven material deformation or surface defects caused by too fast forming speed. At the same time, the number of coils and tension of the spring can be adjusted in real time, and can be flexibly adjusted according to the design requirements of the spring to ensure that the size and mechanical properties of each spring meet the design standards. This process can minimize material waste, improve production efficiency, and ensure the forming quality and precision of the spring.

[0026] In S5, the electroplating process includes nickel electroplating and chromium electroplating, and the thickness of the electroplated layers is 6 μm and 8 μm respectively, so as to enhance the corrosion resistance thereof; The nickel-chromium combination of the plating not only enhances the hardness of the spring surface, but also significantly improves its corrosion resistance. The nickel layer can provide excellent anti-corrosion protection, while the chromium layer forms a dense protective film on the surface, which effectively prevents moisture, acid-base gases and other external environments from corroding the spring surface, thereby extending the service life of the spring. The appropriate plating thickness can meet the anti-corrosion requirements without being too thick to affect the elasticity and precision of the spring. Therefore, this electroplating process can effectively improve the comprehensive performance of the spring, especially in a humid and highly corrosive environment, to ensure the long-term stable operation of the spring and reduce damage and failures caused by corrosion.

[0027] In S6, the carburizing treatment adopts a gas carburizing method, the carburizing atmosphere contains 10%-15% methane, the temperature is 930° C., and the carburizing time is 3 hours; The gas carburizing process can achieve precise adjustment of the surface hardened layer of the spring by controlling the carburizing temperature, time and atmosphere composition. The use of methane as the carbon source in the carburizing atmosphere can effectively control the depth and uniformity of the carburized layer, thereby improving the wear resistance and strength of the spring. By precisely controlling the temperature and atmosphere during the carburizing process, the transition between the surface hardened layer and the matrix is ​​smoother, avoiding the performance difference between the hard and brittle outer layer and the soft inner layer, ensuring that the spring has excellent fatigue resistance and high load bearing capacity. The carburized spring can effectively resist friction and fatigue in the working environment of the shock absorber, greatly extending its service life and reliability.

[0028] In S7, the dimension correction and straightening are performed by combining a laser scanner and an automatic straightening machine to ensure the geometric dimension and shape accuracy of the spring; The laser scanner can accurately measure the geometric dimensions of the spring to ensure that the shape and dimensional accuracy of the spring meet the requirements, including but not limited to the straightness and free height of the spring. The automatic straightening machine can automatically correct the shape of the spring during the production process to ensure that it maintains the correct geometric form and avoids performance problems caused by deformation or uneven stress. This technical solution combines modern automated measurement and correction technology to maintain high precision for each spring in large-scale production, reduce the workload of manual measurement and correction, improve production efficiency, and ensure the high quality of the final product.

[0029] In the S9, the factory inspection adopts air tightness test and static strength test to ensure the performance stability and safety of the spring when used in the shock absorber; The air tightness test can ensure that the spring will not leak gas or fail due to poor sealing performance during operation; the static strength test can evaluate the bearing capacity of the spring under static load and ensure that the spring will not break or deform due to overload during operation. Through these strict factory inspections, it can be ensured that each batch of springs meets the use requirements and reduces the safety hazards caused by spring failure.

[0030] In S8, the quality inspection includes: S81, Dimensional accuracy inspection: S811. Use a high-precision three-dimensional measuring machine to measure the dimensions of each spring in all directions, including but not limited to the outer diameter, inner diameter and free height of the spring; the measurement error is ±0.1mm; for mass production, at least 5% of each batch of products must be randomly sampled for inspection to ensure that they meet the design requirements; S812. Check the number of spiral turns of each spring to ensure that it is consistent with the number of turns in the design requirements; if the error is found to exceed the set tolerance range, the spring will be scrapped and the production process will need to be adjusted; S82, surface quality inspection: S821. Use a surface finish tester to test the surface finish of the spring, and the surface roughness value is less than 0.8μm; S822. Test the coating of the spring and use an electronic probe analyzer to accurately measure the thickness of the coating to ensure that the thickness of the coating meets the standard requirements; S83, hardness and strength test: S831. Use Rockwell hardness tester to test the surface hardness of the spring to ensure that the hardness meets the design requirements; S832. Use a tensile testing machine to test the tensile strength of the spring to ensure that its tensile strength meets the requirements. The tensile speed of the tensile test is controlled at 5 mm / min. S84, fatigue life test: S841. Use a fatigue testing machine to test the durability of the spring. Repeated loading and unloading is used to simulate the load of the spring in actual shock absorber use. The loading frequency is 5 Hz, the maximum load is 1.3-1.5 times the rated load of the spring, and at least 100,000 cycles of loading are performed. S842. Evaluate the fatigue life of the spring by monitoring any cracks or signs of failure during the test, and adjust the tension and shape of the spring appropriately based on the test results to ensure that it has excellent elasticity and durability under normal use; S85, Anti-corrosion Performance Test: S851, Salt spray test: Use neutral salt spray test standard to test the anti-corrosion performance of the spring. The test duration is 48 hours to ensure that there is no obvious rust or corrosion on the spring surface. S852, Sodium chloride solution immersion test: Soak the spring in 5% sodium chloride solution for 48 hours, and then check the integrity of the coating and the surface corrosion; The quality inspection procedures in the present invention include dimensional accuracy inspection, surface quality inspection, hardness and strength inspection, fatigue life inspection and anti-corrosion performance inspection; the dimensional accuracy inspection can ensure that the geometric dimensions of the spring meet the design requirements, thereby avoiding incompatibility or unstable working performance caused by dimensional deviation; the surface quality inspection ensures the surface finish of the spring and the integrity of the coating, avoiding fatigue cracks or corrosion problems caused by surface defects; the hardness and strength inspection can verify whether the spring has excellent hardness and strength, ensuring that it will not deform or break due to excessive load during operation, thereby improving the service life and safety of the spring; the fatigue life inspection simulates the repeated loading of the spring in actual use, predicts its durability and fatigue performance in long-term use, and reduces the risk of failure; the anti-corrosion performance inspection can evaluate the corrosion resistance of the spring in a specific environment, avoid corrosion problems caused by the external environment, and ensure the long-term reliability and stability of the spring.

[0031] 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 processing technology for a spring for a shock absorber, characterized in that: The following steps are involved: S1. Material selection and pretreatment: Select high-strength alloy steel or stainless steel as raw material, requiring its yield strength to be no less than 600MPa, tensile strength to be no less than 1000MPa, and excellent elastic recovery; the chemical composition of alloy steel includes but is not limited to C: 0.7%-0.9%, Si: 0.2%-0.3%, Mn: 0.5%-0.8%, Cr: 0.5%-0.7%, Ni: 0.3%-0.5%, Mo: 0.2%-0.3%; degrease and rust the selected steel, use pickling process to remove surface oxides to ensure the cleanliness of the steel surface, and use sandblasting to further clean impurities; S2. Raw material cutting: Use CNC cutting equipment to cut the raw materials to ensure that the length of the cut material meets the design requirements of the spring; S3. Stretching and heat treatment of raw materials: The treated steel is stretched to adjust the initial size of the steel to meet the design requirements of the spring. After stretching, high-temperature annealing is performed. The annealing temperature is controlled within the range of 550℃-600℃. The duration is adjusted according to the diameter and length of the steel. After annealing, the grains of the steel are homogenized to improve its plasticity and strength. S4, cold forming: the annealed steel is sent to the CNC spring forming machine for precise spring forming. According to the design requirements of the spring, the tension, pressure and rotation angle of the forming machine are adjusted to make the steel be wound according to the predetermined shape, and ensure that the wire diameter, inner diameter and outer diameter of each circle are uniform; S5. Surface treatment and anti-corrosion treatment: The spring after forming needs to be surface hardened and anti-corrosion treated. First, the surface is phosphated to increase the adhesion of the coating, and an anti-corrosion nickel-chromium alloy layer is plated on the surface of the spring by electroplating. The thickness of the coating is controlled at 5μm-15μm, so that the hardness range of the spring surface is 60HRC-65HRC. S6. Heat treatment and tempering: Carburizing is used to heat treat the formed springs. The carburizing temperature is controlled at 900℃-950℃. The carburizing time is adjusted according to the size of the springs. After carburizing, tempering is performed. The tempering temperature is controlled at 200℃-250℃. The overall hardness range of the spring after heat treatment and tempering is 45HRC-55HRC, so that the hardness and toughness of the springs reach the best balance to avoid brittle fracture during use. S7. Dimension correction and straightening: Use an automatic straightening machine to correct the size of the formed spring to ensure that the straightness and shape of the spring are not deformed. After straightening, check the shape and size of the spring to confirm that it meets the design requirements. Use a laser measuring instrument to detect the various dimensions of the spring to ensure that its accuracy is within 0.1mm; S8. Inspection and quality control: Strict quality inspection is carried out on each batch of springs produced to ensure that all products meet the standards; S9. Packaging and factory inspection: Finally, all qualified springs will be marked and packaged according to customer requirements and undergo final factory inspection; factory inspection includes appearance inspection, packaging inspection, and random sampling of samples for tensile strength and fatigue testing to ensure that each batch of products can meet the use requirements.

2. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In the S1, the alloy steel adopts a special alloying composition, wherein the C content is 0.8%, the Mn content is 0.6%, the Cr content is 0.6%, the Mo content is 0.25%, and the V content is 0.2%, so as to improve the fatigue resistance and corrosion resistance of the spring.

3. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In S3, annealing is performed in a protective atmosphere, using nitrogen or argon as a protective gas to avoid oxidation of the steel surface and improve the surface quality.

4. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In S4, the forming speed of the CNC spring forming machine is controlled at ≤1000r / min, and the number of coils and tension of the spring are adjusted in real time.

5. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In S5, the electroplating process includes nickel electroplating and chromium electroplating, and the thickness of the electroplated layers is 6 μm and 8 μm respectively, so as to enhance the corrosion resistance thereof.

6. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In S6, the carburizing treatment adopts a gas carburizing method, the carburizing atmosphere contains 10%-15% methane, the temperature is 930° C., and the carburizing time is 3 hours.

7. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In the S7, dimension correction and straightening are combined with a laser scanner and an automatic straightening machine to ensure the geometrical dimension and shape accuracy of the spring.

8. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In the S9, the factory inspection adopts air tightness test and static strength test to ensure the performance stability and safety of the spring when used in the shock absorber.

9. The processing technology of a spring for a shock absorber according to claim 1, characterized in that: In S8, the quality inspection includes: S81, Dimensional accuracy inspection: S811. Use a high-precision three-dimensional measuring machine to measure the dimensions of each spring in all directions, including but not limited to the outer diameter, inner diameter and free height of the spring; the measurement error is ±0.1mm; for mass production, at least 5% of each batch of products must be randomly sampled for inspection to ensure that they meet the design requirements; S812. Check the number of spiral turns of each spring to ensure that it is consistent with the number of turns in the design requirements; if the error is found to exceed the set tolerance range, the spring will be scrapped and the production process will need to be adjusted; S82, surface quality inspection: S821. Use a surface finish tester to test the surface finish of the spring, and the surface roughness value is less than 0.8μm; S822. Test the coating of the spring and use an electronic probe analyzer to accurately measure the thickness of the coating to ensure that the thickness of the coating meets the standard requirements; S83, hardness and strength test: S831. Use Rockwell hardness tester to test the surface hardness of the spring to ensure that the hardness meets the design requirements; S832. Use a tensile testing machine to test the tensile strength of the spring to ensure that its tensile strength meets the requirements. The tensile speed of the tensile test is controlled at 5 mm / min. S84, fatigue life test: S841. Use a fatigue testing machine to test the durability of the spring. Repeated loading and unloading is used to simulate the load of the spring in actual shock absorber use. The loading frequency is 5 Hz, the maximum load is 1.3-1.5 times the rated load of the spring, and at least 100,000 cycles of loading are performed. S842. Evaluate the fatigue life of the spring by monitoring any cracks or signs of failure during the test, and adjust the tension and shape of the spring appropriately based on the test results to ensure that it has excellent elasticity and durability under normal use; S85, Anti-corrosion Performance Test: S851, Salt spray test: Use neutral salt spray test standard to test the anti-corrosion performance of the spring. The test duration is 48 hours to ensure that there is no obvious rust or corrosion on the spring surface. S852, Sodium chloride solution immersion test: Soak the spring in 5% sodium chloride solution for 48 hours, and then check the integrity of the coating and surface corrosion.

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