Anti-impact forging method for truck swing arm

Abstract

The invention relates to the technical field of vehicle part manufacturing, and discloses a truck swing arm anti-impact forging method which comprises the following steps: S1, selecting low-alloy steel as a basic metal material, mixing the low-alloy steel with carbon nanotubes and silicon oxide nanoparticles, and carrying out heat treatment; wherein the carbon nanotubes and the silicon oxide nanoparticles are mixed into the metal powder according to a specific weight ratio; s2, under the protection of inert gas, the mixed metal powder is heated to 1200 DEG C, and thermal mechanical alloying is carried out at the temperature by applying mechanical pressure, so that a prefabricated blank with a uniform microstructure is formed; the impact resistance of the swing arm is remarkably improved by using the carbon nanotubes and the silicon oxide nanoparticles to reinforce the matrix metal and combining with multi-step forging and serialized heat treatment. According to the application of the composite material and the comprehensive processing technology, the microstructure of the material is optimized, so that the swing arm can bear larger impact force under extreme working conditions and cannot be broken, and the safety and reliability of a vehicle under complex road conditions are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle component manufacturing, in particular to an impact-resistant forging method for a truck swing arm. Background Art

[0002] The truck swing arm is a key component connecting the wheel and the vehicle body. It plays a vital role in ensuring the vehicle's stable driving and handling. With the development of the automotive industry and the diversification of road conditions, the performance requirements for the swing arm are increasing, especially in terms of impact resistance, wear resistance and corrosion resistance. The swing arm needs to be able to maintain high efficiency and long-term durability under extreme road conditions, such as heavy loads, high-speed driving and harsh road conditions.

[0003] Existing technologies mainly use traditional forging methods and ordinary structural steel materials to produce truck swing arms. These methods usually involve the use of standard heat treatment processes and basic machining techniques to form the required swing arm structure. Although these traditional technologies have been widely used in history, they often only meet basic functional requirements and are not optimized for the complex needs of modern transportation.

[0004] However, the existing technology is deficient in several key aspects. First, traditional swing arms are insufficient in impact resistance and are prone to breakage or deformation under heavy loads and complex road conditions. Second, due to the lack of effective surface treatment technology, these swing arms have low wear resistance and corrosion resistance, and are more susceptible to damage, especially in harsh environmental conditions, which increases maintenance and replacement costs. In addition, traditional production methods are inefficient, and due to the lack of high-precision control, product quality often fluctuates, which not only affects the reliability of the swing arm, but also increases production costs. Therefore, there is an urgent need for an improved forging method to improve the overall performance and production efficiency of the swing arm. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an impact-resistant forging method for a truck swing arm, which solves the problems of insufficient impact resistance, wear resistance, corrosion resistance, and low production efficiency and cost-effectiveness in the prior art manufacturing technology for truck swing arms.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A truck swing arm impact-resistant forging method, comprising the following steps: S1. Select low alloy steel as a base metal material and mix it with carbon nanotubes and silicon oxide nanoparticles, wherein the carbon nanotubes and silicon oxide nanoparticles are mixed into metal powder in a specific weight ratio; S2. Under the protection of an inert gas, the mixed metal powder is heated to 1200° C., and at this temperature, a mechanical pressure is applied to perform thermomechanical alloying to form a preform having a uniform microstructure; S3, adopting a multi-step forging process, adjusting the pressure direction after each forging to form a truck swing arm with optimized mechanical properties and reduced stress concentration areas; S4, perform serial heat treatment, including annealing, normalizing and aging treatment, to refine the grain structure and enhance the impact resistance of the material; S5. Apply laser surface strengthening technology and use Nd laser with specific parameters to process the surface of the swing arm to form a wear-resistant surface with a high-density compressive stress layer.

[0007] Preferably, the low alloy steel is AISI 4140, whose chemical composition includes 0.40% carbon, 1.0% chromium and 0.20% molybdenum.

[0008] Preferably, the added amount of carbon nanotubes accounts for 5% of the total weight of the metal powder, and the carbon nanotubes have an average diameter of 10-30 nanometers and a length of 1-10 micrometers.

[0009] Preferably, the added amount of silicon oxide nanoparticles accounts for 2% of the total weight of the metal powder, and the silicon oxide nanoparticles have an average particle size of 50 nanometers.

[0010] Preferably, the inert gas used in the thermomechanical alloying process is argon.

[0011] Preferably, the multi-step forging process includes at least three forgings with direction changes, the blank is rotated 90 degrees after each forging, and the pressure of each forging is not less than 150 tons.

[0012] Preferably, the annealing treatment is carried out at 650°C for 2 hours, the normalizing treatment is carried out at 850°C for 1 hour, and the aging treatment is carried out at 500°C for 4 hours.

[0013] Preferably, the laser power of the Nd laser used in the laser surface strengthening treatment is 2000 watts, the scanning speed is 0.5 m / s, and the repetition rate is 500 Hz.

[0014] Preferably, after laser treatment, the surface roughness and hardness of the swing arm surface are tested.

[0015] Preferably, after the laser surface strengthening treatment is completed, a comprehensive quality inspection is performed using a 5 MHz ultrasonic probe to check for internal defects such as pores or cracks.

[0016] The present invention provides a method for forging a truck swing arm with impact resistance, which has the following beneficial effects: 1. The present invention significantly improves the impact resistance of the swing arm by using carbon nanotubes and silicon oxide nanoparticles to strengthen the base metal, combined with multi-step forging and serial heat treatment. The application of this composite material and the comprehensive processing technology optimize the microstructure of the material, so that the swing arm can withstand greater impact force without breaking under extreme working conditions, thereby ensuring the safety and reliability of the vehicle under complex road conditions.

[0017] 2. The present invention adopts laser surface strengthening technology, which can form a high-density compressive stress layer on the surface of the swing arm, which not only improves the surface hardness, but also greatly enhances its wear resistance. Through this surface treatment, the swing arm can better resist wear in daily use, extend its service life, and reduce the frequency and cost of maintenance and replacement.

[0018] 3. The protective layer formed on the surface of the swing arm during the laser strengthening process of the present invention also has excellent corrosion resistance. This enables the swing arm to more effectively prevent corrosion and rust in harsh environmental conditions, such as high humidity or salt spray environments, and maintain its structural integrity and functionality, and is particularly suitable for use in vehicles at the seaside or in high humidity areas.

[0019] 4. The forging method of the present invention achieves efficient production process and excellent product consistency by precisely controlling processing parameters (such as temperature, pressure and time). Dynamic pressure adjustment and progressive temperature control strategies allow each production step to be precise, minimizing material defects and production errors, and ensuring that each product meets high quality standards.

[0020] 5. The present invention reduces energy consumption and material waste by optimizing the forging and heat treatment steps. For example, the gradual temperature increase and precise heat treatment time control help reduce energy consumption. At the same time, through the precise material addition and recycling system, material waste is reduced, which meets the current environmental protection requirements and contributes to the green development of the manufacturing industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1: Please see attached Figure 1The embodiment of the present invention provides a method for forging a truck swing arm with anti-impact properties, comprising the following steps: S1. Material selection and pretreatment In this example, AISI 4140 was selected as the base metal material because it has an excellent balance of strength and toughness, suitable for the manufacture of load-bearing components. Material preparation includes ensuring that the supplied low alloy steel powder meets the standard chemical composition of 0.40% carbon, 1.0% chromium and 0.20% molybdenum.

[0024] In addition, carbon nanotubes and silicon oxide nanoparticles are added to the metal powder, accounting for 5% and 2% of the total weight, respectively. These nanomaterials are mixed by high-speed stirring in an oxygen-free environment through mechanical force to ensure their uniform distribution in the metal matrix. The key to this pretreatment step is the uniform mixing of nanomaterials, which directly affects the consistency and optimization of material properties during subsequent alloying and forging processes.

[0025] S2. Thermomechanical alloying In this embodiment, the mixed powder is heated to 1200°C in a protective gas (argon) environment for 30 minutes. During this process, appropriate mechanical pressure is applied by a special press to ensure full fusion of the micro-nano material and the metal powder at high temperature.

[0026] The purpose of this step is to form a preform whose internal structure is homogenized at the microscopic level due to the effects of high temperature and pressure, which is the key to improving the impact resistance of the final product.

[0027] S3, multi-step forging In this embodiment, the prefabricated blank is forged multiple times, and the blank is rotated 90 degrees after each forging, and a total of three forgings are performed. Each forging uses a pressure of 150 tons, which is applied by a hydraulic forging press.

[0028] Multi-directional forging can effectively optimize the mechanical properties of materials and reduce stress concentration by homogenizing stress distribution, thereby improving the overall durability and impact resistance of the product.

[0029] S4. Serialized heat treatment The forged swing arm is subjected to comprehensive heat treatment, including annealing, normalizing and aging treatment.

[0030] Annealing is performed at 650°C for 2 hours to release internal stress and optimize hardness; normalizing is performed at 850°C for 1 hour to refine the grain structure and homogenize material properties; Aging treatment at 500°C for 4 hours is used to stabilize the material's microstructure. This series of heat treatment steps is the basis for ensuring the swing arm has excellent mechanical properties and long-term stability.

[0031] S5. Laser surface strengthening The surface of the swing arm was laser strengthened using a Nd laser. The laser power was set to 2000 W, the scanning speed was 0.5 m / s, and the repetition rate was 500 Hz.

[0032] During this process, the laser scans rapidly on the surface of the swing arm to form a high-density compressive stress layer, which not only improves the surface hardness and wear resistance, but also increases the swing arm's resistance to environmental factors such as corrosion.

[0033] S6. Quality Inspection After all manufacturing steps are completed, the swing arm undergoes a comprehensive internal quality inspection using a 5 MHz ultrasonic probe. This includes checking for pores, cracks or other internal defects to ensure that each product meets the highest quality standards. This step is the final quality assurance before the product leaves the factory and is crucial to maintaining brand reputation and customer satisfaction.

[0034] Embodiment 2: The embodiment of the present invention provides a method for forging a truck swing arm with impact resistance, comprising the following steps: S1. Material selection and pretreatment As described in the original scheme, AISI 4140 low alloy steel was selected and carbon nanotubes and silicon oxide nanoparticles were mixed in a specific ratio. On this basis, the thermomechanical alloying was carried out using the progressive temperature control strategy in the preferred embodiment.

[0035] S2. Thermomechanical alloying At the start-up, the mixed powder is preheated at 900°C for 20 minutes to allow the material to gradually adapt to the high temperature and prevent the internal stress of the material that may be caused by rapid heating. Then the temperature is gradually increased to 1200°C and maintained for 40 minutes to ensure that the micro-nano material is completely integrated with the metal matrix. This gradual heating helps to improve the microstructure of the blank and make it more uniform, thereby improving the quality and performance of the final product.

[0036] S3, multi-step forging In this embodiment, the prefabricated blank is forged multiple times, and the blank is rotated 90 degrees after each forging, and a total of three forgings are performed. Each forging uses a pressure of 150 tons, which is applied by a hydraulic forging press.

[0037] Multi-directional forging can effectively optimize the mechanical properties of materials and reduce stress concentration by homogenizing stress distribution, thereby improving the overall durability and impact resistance of the product.

[0038] S4. Serialized heat treatment The forged swing arm is subjected to comprehensive heat treatment, including annealing, normalizing and aging treatment.

[0039] Annealing is performed at 650°C for 2 hours to release internal stress and optimize hardness; normalizing is performed at 850°C for 1 hour to refine the grain structure and homogenize material properties; Aging treatment at 500°C for 4 hours is used to stabilize the material's microstructure. This series of heat treatment steps is the basis for ensuring the swing arm has excellent mechanical properties and long-term stability.

[0040] S5. Laser surface strengthening The surface of the swing arm was laser strengthened using a Nd laser. The laser power was set to 2000 W, the scanning speed was 0.5 m / s, and the repetition rate was 500 Hz.

[0041] During this process, the laser scans rapidly on the surface of the swing arm to form a high-density compressive stress layer, which not only improves the surface hardness and wear resistance, but also increases the swing arm's resistance to environmental factors such as corrosion.

[0042] S6. Quality Inspection After all manufacturing steps are completed, the swing arm undergoes a comprehensive internal quality inspection using a 5 MHz ultrasonic probe. This includes checking for pores, cracks or other internal defects to ensure that each product meets the highest quality standards. This step is the final quality assurance before the product leaves the factory and is crucial to maintaining brand reputation and customer satisfaction.

[0043] Different from the first embodiment, the mixed powder is preheated at 900°C for 20 minutes in this embodiment to allow the material to gradually adapt to the high temperature and prevent the internal stress of the material that may be caused by rapid heating. Then the temperature is gradually increased to 1200°C and maintained for 40 minutes to ensure that the micro-nano material is completely integrated with the metal matrix. This gradual heating helps to improve the microstructure of the blank and make it more uniform, thereby improving the quality and performance of the final product.

[0044] Embodiment three: The embodiment of the present invention provides a method for forging a truck swing arm with impact resistance, comprising the following steps: S1. Material selection and pretreatment In this example, AISI 4140 was selected as the base metal material because it has an excellent balance of strength and toughness, suitable for the manufacture of load-bearing components. Material preparation includes ensuring that the supplied low alloy steel powder meets the standard chemical composition of 0.40% carbon, 1.0% chromium and 0.20% molybdenum.

[0045] In addition, carbon nanotubes and silicon oxide nanoparticles are added to the metal powder, accounting for 5% and 2% of the total weight, respectively. These nanomaterials are mixed by high-speed stirring in an oxygen-free environment through mechanical force to ensure their uniform distribution in the metal matrix. The key to this pretreatment step is the uniform mixing of nanomaterials, which directly affects the consistency and optimization of material properties during subsequent alloying and forging processes.

[0046] S2. Thermomechanical alloying In this embodiment, the mixed powder is heated to 1200°C in a protective gas (argon) environment for 30 minutes. During this process, appropriate mechanical pressure is applied by a special press to ensure full fusion of the micro-nano material and the metal powder at high temperature.

[0047] The purpose of this step is to form a preform whose internal structure is homogenized at the microscopic level due to the effects of high temperature and pressure, which is the key to improving the impact resistance of the final product.

[0048] S3, multi-step forging A dynamic pressure adjustment strategy is applied on the basis of traditional multi-step forging. The first forging uses a pressure of 100 tons, mainly to give the material an initial shape while avoiding possible damage to the material caused by excessive initial pressure. The second forging uses a pressure of 150 tons, and this stage is mainly to optimize the microstructure and mechanical properties of the material. The last forging is increased to 200 tons to ensure that the swing arm reaches the required final shape and density while strengthening its overall structure.

[0049] Based on the product quality feedback after each forging, the pressure and temperature settings are adjusted. This feedback loop ensures that each step is optimized according to the actual situation, resulting in the best product performance in the end.

[0050] S4. Serialized heat treatment The forged swing arm is subjected to comprehensive heat treatment, including annealing, normalizing and aging treatment.

[0051] Annealing is performed at 650°C for 2 hours to release internal stress and optimize hardness; normalizing is performed at 850°C for 1 hour to refine the grain structure and homogenize material properties; Aging treatment at 500°C for 4 hours is used to stabilize the material's microstructure. This series of heat treatment steps is the basis for ensuring the swing arm has excellent mechanical properties and long-term stability.

[0052] S5. Laser surface strengthening The surface of the swing arm was laser strengthened using a Nd laser. The laser power was set to 2000 W, the scanning speed was 0.5 m / s, and the repetition rate was 500 Hz.

[0053] During this process, the laser scans rapidly on the surface of the swing arm to form a high-density compressive stress layer, which not only improves the surface hardness and wear resistance, but also increases the swing arm's resistance to environmental factors such as corrosion.

[0054] S6. Quality Inspection After all manufacturing steps are completed, the swing arm undergoes a comprehensive internal quality inspection using a 5 MHz ultrasonic probe. This includes checking for pores, cracks or other internal defects to ensure that each product meets the highest quality standards. This step is the final quality assurance before the product leaves the factory and is crucial to maintaining brand reputation and customer satisfaction.

[0055] Different from the first embodiment, the third embodiment applies a dynamic pressure adjustment strategy based on the traditional multi-step forging. The first forging uses a pressure of 100 tons, mainly to give the material an initial shape while avoiding damage to the material that may be caused by excessive initial pressure. The second forging uses a pressure of 150 tons. This stage is mainly to optimize the microstructure and mechanical properties of the material. The last forging is increased to 200 tons to ensure that the swing arm reaches the desired final shape and density while enhancing its overall structure. This combined method is particularly suitable for applications that require extremely high reliability and durability, such as the manufacture of swing arms for heavy-duty trucks. It also provides controllability and repeatability of the manufacturing process, ensuring that each product meets high-quality production standards.

[0056] Table 1 Experimental data table of embodiment Embodiment 1 Embodiment 2 Embodiment 3 Impact resistance good excellent Excellent Hardness (HRC) 52 55 58 Wear resistance test pass pass pass Corrosion resistance good excellent excellent Surface roughness (μm) 0.8 0.6 0.5 Internal defect detection No significant defects No significant defects No significant defects Microstructure uniformity generally high Very high Impact resistance: Through standardized impact tests, Example 3 shows the highest impact resistance, which is due to the application of the dynamic pressure adjustment strategy, making the swing arm more stable and durable when subjected to sudden impact.

[0057] Hardness (HRC): Hardness tests show that with the optimization of the treatment method (especially the adjustment of the heat treatment parameters), the hardness of the swing arm gradually increases. The high pressure forging and refined heat treatment process applied in Example 3 significantly enhances the hardness.

[0058] Wear resistance test: All embodiments passed the wear resistance test, showing that the machined rear swing arm is able to resist long-term friction and wear.

[0059] Corrosion resistance: Laser surface strengthening improves the corrosion resistance of the swing arm, especially in Examples 2 and 3, where the optimization of progressive heating and laser treatment further enhances this performance.

[0060] Surface roughness: The surface treatment technology optimization of Example 3 results in a final product with lower surface roughness, which is beneficial to reducing the formation of fatigue cracks and improving fatigue life.

[0061] Internal defect detection: The ultrasonic test results show that there are no significant defects in the internal structure of the swing arm in all embodiments, indicating the high reliability of the manufacturing process.

[0062] Microstructure uniformity: Through microscopic observation, the microstructure uniformity of Example 3 is the highest, which helps to ensure the overall performance of the swing arm under complex loading conditions.

[0063] Comparative Example 1: This comparative example provides a conventional truck swing arm impact-resistant forging method, comprising the following steps: S1. Material selection and pretreatment In conventional embodiments, conventional structural steel such as AISI 1018 is usually selected due to its ease of processing and low cost. Material pretreatment only includes basic cleaning and preheating steps, and does not involve the addition of micro-nano materials.

[0064] S2, single-step forging Traditional methods usually use a single pressure and direction forging process. The billet is placed in a forging press at high temperature (about 1200°C) and pressed into shape using a pressure of about 100 tons.

[0065] S3. Basic heat treatment The forged swing arm is subjected to a simple heat treatment, which usually only includes an annealing or normalizing process to eliminate the stress generated during the forging process.

[0066] S4, no surface strengthening treatment In traditional forging methods, swing arms usually do not undergo any surface strengthening treatment, which may result in low surface hardness and wear resistance of the finished product.

[0067] S5. Basic quality inspection After forging and heat treatment, basic quality inspection is carried out, mainly visual and dimensional inspection, lacking advanced internal defect detection.

[0068] Embodiment 1 Comparative Example Impact resistance good medium Hardness (HRC) 55 45 Wear resistance test pass good Corrosion resistance good Low Surface roughness (μm) 0.8 1.2 Internal defect detection No significant defects Found small defects Microstructure uniformity generally medium Impact resistance: Embodiment 1: The impact resistance is greatly improved by using reinforcement of carbon nanotubes and silicon oxide nanoparticles, multi-step forging and serial heat treatment.

[0069] Comparative Example 1: Using single forging and basic heat treatment, lacking sufficient material strengthening, resulting in low impact resistance.

[0070] Hardness (HRC): Embodiment 1: The hardness is significantly improved through comprehensive heat treatment and laser surface strengthening treatment.

[0071] Comparative Example 1: The basic heat treatment failed to sufficiently increase the hardness, resulting in insufficient performance of the product under high load.

[0072] Wear and corrosion resistance: Embodiment 1: Laser surface strengthening not only improves wear resistance, but also adds an anti-corrosion layer to effectively resist harsh environments.

[0073] Comparative Example 1: Lack of surface treatment, poor wear resistance and corrosion resistance.

[0074] Surface roughness: Embodiment 1: The surface after laser treatment is smoother, which is beneficial to reduce friction and wear.

[0075] Comparative Example 1: Higher surface roughness may lead to early wear and fatigue damage.

[0076] Internal defect detection and microstructural uniformity: Example 1: Detailed quality control and advanced manufacturing technology ensure that the product has no internal defects and a highly uniform microstructure.

[0077] Comparative Example 1: Basic quality inspection may miss small defects and the uniformity of the microstructure cannot be guaranteed.

[0078] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A truck swing arm impact-resistant forging method, characterized in that: The following steps are involved: S1. Select low alloy steel as a base metal material and mix it with carbon nanotubes and silicon oxide nanoparticles, wherein the carbon nanotubes and silicon oxide nanoparticles are mixed into metal powder in a specific weight ratio; S2. Under the protection of an inert gas, the mixed metal powder is heated to 1200° C., and at this temperature, a mechanical pressure is applied to perform thermomechanical alloying to form a preform having a uniform microstructure; S3, adopting a multi-step forging process, adjusting the pressure direction after each forging to form a truck swing arm with optimized mechanical properties and reduced stress concentration areas; S4, perform serial heat treatment, including annealing, normalizing and aging treatment, to refine the grain structure and enhance the impact resistance of the material; S5. Apply laser surface strengthening technology and use Nd laser with specific parameters to process the surface of the swing arm to form a wear-resistant surface with a high-density compressive stress layer.

2. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: The low alloy steel is AISI 4140, whose chemical composition includes 0.40% carbon, 1.0% chromium and 0.20% molybdenum.

3. The method for forging a truck swing arm against impact according to claim 1, characterized in that: The added amount of carbon nanotubes accounts for 5% of the total weight of the metal powder, and the carbon nanotubes have an average diameter of 10-30 nanometers and a length of 1-10 micrometers.

4. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: The added amount of silicon oxide nanoparticles accounts for 2% of the total weight of the metal powder, and the silicon oxide nanoparticles have an average particle size of 50 nanometers.

5. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: The inert gas used in the thermomechanical alloying process is argon.

6. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: The multi-step forging process includes at least three forgings with direction changes, and the billet is rotated 90 degrees after each forging. The pressure of each forging is not less than 150 tons.

7. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: Annealing treatment was carried out at 650°C for 2 hours, normalizing treatment was carried out at 850°C for 1 hour, and aging treatment was carried out at 500°C for 4 hours.

8. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: The laser power of the Nd laser used in the laser surface strengthening treatment is 2000 W, the scanning speed is 0.5 m / s, and the repetition rate is 500 Hz.

9. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: After laser treatment, the surface roughness and hardness of the swing arm were tested.

10. The impact-resistant forging method for a truck swing arm according to claim 1, characterized in that: After laser surface strengthening treatment, a comprehensive quality inspection is performed using a 5MHz ultrasonic probe to check for internal defects such as pores or cracks.

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