A post-treatment method for enhancing the performance of automotive alloy parts

Abstract

The application discloses a post-treatment method for enhancing the performance of automobile alloy parts, and aims at enhancing the quenching effect of the automobile alloy parts and enhancing the strength of the automobile alloy parts by preparing a quenching liquid; the wear resistance of the automobile alloy parts is enhanced by adding a tempering medium supplement in a tempering process; the temperature hard toughness ratio of the automobile alloy parts is controlled by preparing a tempering medium to control the cooling rate during tempering, so that the connecting effect of the automobile alloy parts with threads with different hardness is improved, and the occurrence of the thread slipping phenomenon is reduced.

Description

Technical Field

[0001] This invention belongs to the field of automotive alloy parts preparation technology, specifically relating to a post-processing method for enhancing the performance of automotive alloy parts. Background Technology

[0002] Due to their unique operating environment, automotive alloy parts require high strength and wear resistance. The common method to enhance their strength is through quenching during heat treatment. The effectiveness of quenching significantly impacts the strength of automotive alloy parts, and this effectiveness depends on the properties of the quenching fluid. Currently, the most commonly used quenching fluid is PAG quenching fluid. Although it has many advantages, its oxidation resistance and high-temperature stability are poor. During the quenching process, it can cause oxidation and other problems on the surface of automotive alloy parts, thus affecting their strength.

[0003] Wear resistance is another important property of automotive alloy parts. Generally, the method to enhance its wear resistance is to cover it with a wear-resistant coating. However, this method will increase the process flow, making the production process more complicated and costly. Summary of the Invention

[0004] The primary objective of this invention is to provide a post-processing method for enhancing the performance of automotive alloy parts.

[0005] The second objective of this invention is to provide a method for preparing a quenching fluid.

[0006] The third objective of this invention is to provide a method for preparing a tempering medium replenishing agent.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention includes the following steps: A post-processing method for enhancing the performance of automotive alloy parts, comprising the following steps: (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8~9 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 530~570℃ and hold for 50~60min, then continue heating to 920~930℃ and hold for 30~40min; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 40~50℃, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 60-70℃ and pH 9-10 and then dry them. (5) Heat the dried automotive alloy parts to 180~200℃ and keep them warm for 3~4 hours. Then place them in a tempering pool and temper them in tempering medium No. 1 at a temperature of 70~80℃. Then place them in tempering medium No. 2 at a temperature of room temperature for cooling.

[0008] Furthermore, the preparation method of the quenching fluid in step (3) is as follows: Add 35-45 parts of water to 40-50 parts of PAG polymer, then heat to 30-34℃ and stir at 100-150 r / min for 25-35 min. Then add 0.5-0.7 parts of stearamide polyoxyethylene ether phosphate, 0.4-0.6 parts of alkylolamide phosphate and 0.5-0.7 parts of sodium bicarbonate. Then heat to 40-45℃ and stir at 100-150 r / min for 10-20 min to obtain the quenching liquid. Furthermore, in step (5), both tempering medium No. 1 and tempering medium No. 2 are tempering oil.

[0009] Furthermore, the tempering medium No. 2 mentioned in step (5) also includes a tempering medium replenisher, the preparation method of which is as follows: Add 5-7 parts of lubricant alkyl salicylate molybdenum and 1-3 parts of defoamer silicone oil to 40-50 parts of polyurethane liquid resin, and stir at 300-400 r / min for 20-30 min. Then add 60-70 parts of wear-resistant agent boron nitride and 2-4 parts of adhesion promoter hydroxyethyl methacrylate phosphate, and continue stirring for 30-40 min. Finally, add 3-5 parts of curing agent and continue stirring for 6-8 min to obtain tempering medium replenisher. The curing agent is obtained by mixing dithiol alkyltin and ethyl acetate in a mass ratio of 1:3~4.

[0010] Furthermore, the automotive alloy parts include stamped parts, welded parts, and threaded connection alloy parts.

[0011] Currently, automotive assembly primarily utilizes automated mechanical installation. However, this process can lead to defects such as thread stripping due to mismatch between the automotive alloy parts and the threads, increasing rework rates and reducing production efficiency. Furthermore, this invention involves quenching the automotive alloy parts and adding additives during the tempering process, significantly enhancing their strength and hardness. This results in a greater hardness difference between the automotive alloy parts and the threads, further increasing the likelihood of thread stripping. Therefore, this invention addresses this issue by developing a tempering cooling medium to control the cooling rate of the automotive alloy parts during tempering, thereby controlling their hardness and toughness. By controlling the hardness-to-toughness ratio, a suitable hardness range can be established, allowing for compatibility with materials within a specific hardness range, expanding its applicability, and reducing the occurrence of problems such as thread stripping.

[0012] A method for enhancing the performance of threaded connection alloy parts includes a tempering cooling medium used during tempering, specifically: Add 3-5 parts of antioxidant butylated hydroxyanisole, 0.3-0.5 parts of defoamer tributyl phosphate, 10-14 parts of hydrogenated methyl rosinate, and 8-10 parts of hydrogenated castor oil isostearate to 50-60 parts of 150BS bright oil. Then heat to 45-55℃ and stir at 100-200 r / min for 1.5-2.5 h. After stirring, the tempering cooling medium is obtained.

[0013] The beneficial effects of this invention are as follows: (1) Compared with polyoxyethylene ether phosphate, stearamide polyoxyethylene ether phosphate can enhance the oxidation resistance and fire resistance of quenching fluid as a component. The enhanced oxidation resistance can effectively reduce the oxides and precipitates generated by oxidation reaction during quenching, avoid the problems of surface oxidation and surface carbonization of automotive alloy parts, and thus enhance the strength of automotive alloy parts. However, polyoxyethylene ether phosphate has poor thermal stability and will generate more residues under high temperature conditions. The residues may adhere to the surface of automotive alloy parts, forming defects or poor textures. At the same time, the residues will also affect the heat transfer of quenching fluid, thereby affecting the cooling rate of automotive alloy parts, resulting in lower strength. Stearamide polyoxyethylene ether phosphate also has excellent emulsification, dispersion and wetting properties, which can make the quenching fluid have a more uniform cooling effect, thereby improving the quenching effect. (2) Alkyl alcohol amide phosphate is also a high-performance nonionic surfactant with excellent heat resistance, emulsification and wettability. It has a synergistic effect with stearamide polyoxyethylene ether phosphate. At the same time, alkyl alcohol amide phosphate also has a good detergency ability, which can remove contaminants on automotive alloy parts and prevent contaminants from reacting with automotive alloy parts and affecting the quenching effect. Alkyl alcohol amide phosphate also has excellent rust prevention function, which can form a protective film and effectively prevent automotive alloy parts from undergoing oxidation reaction during quenching, thereby affecting the quality of automotive alloy parts. (3) Dithiolated alkyltin can promote the curing of polyurethane resin, making it more complete and thus enhancing its wear resistance. Compared with other curing agents such as propylene glycol, dithiolated alkyltin has stronger stability and shorter curing time, which can make the curing effect of polyurethane resin better. At the same time, dithiolated alkyltin also has the effect of delayed curing, which can make polyurethane resin cure after tempering. On the one hand, it will not affect the tempering effect, and on the other hand, it can make the various components in the supplement uniformly mixed before playing the curing role, further enhancing the wear resistance of automotive alloy parts. (4) Alkyl salicylate molybdenum can be used as a lubricant to enhance the dispersibility of wear-resistant agents in polyurethane resin, so that the various components in polyurethane resin can be mixed evenly. At the same time, alkyl salicylate molybdenum can undergo a decomposition reaction due to the high temperature generated by friction during the friction process. The decomposition products can form a film and cover the automotive alloy parts, further enhancing the wear resistance of automotive alloy parts. (5) The tempering medium prepared in this invention increases its viscosity and reduces its thermal conductivity by adding hydrogenated methyl rosinate and hydrogenated castor oil isostearate to the base oil, thereby reducing the cooling rate of automotive alloy parts. While increasing the viscosity of the tempering medium, hydrogenated methyl rosinate can also enhance its oxidation resistance and heat resistance. Hydrogenated methyl rosinate also has wettability, which can reduce the surface tension between the tempering medium and the automotive alloy parts, so that the tempering medium can be more evenly distributed on the surface of the automotive alloy parts, thereby enhancing the tempering effect. At the same time, hydrogenated methyl rosinate also has film-forming properties, which can form a film on the surface of the automotive alloy parts after tempering, further enhancing its wear resistance. (6) Hydrogenated castor oil isostearate can increase the viscosity of the tempering medium, enhance its dispersibility and wettability, and has a synergistic effect with hydrogenated methyl rosinate. At the same time, it also has film-forming properties, which can form a film on the surface of automotive alloy parts to further enhance their wear resistance. Implementation

[0014] The present invention will be further described in detail below with reference to the embodiments. Example 1

[0015] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0016] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling. Example 2

[0017] Add 45 parts of water to 40 parts of PAG polymer, then heat to 30°C and stir at 150 r / min for 25 min. Then add 0.5 parts of stearamide polyoxyethylene ether phosphate, 0.6 parts of alkylolamide phosphate and 0.7 parts of sodium bicarbonate, then heat to 45°C and stir at 100 r / min for 20 min to obtain the quenching liquid.

[0018] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 570°C and hold for 50 minutes, then continue heating to 920°C and hold for 40 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 40°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 70°C and pH 9 and then dry them. (5) Heat the dried automotive alloy parts to 180°C and keep them warm for 4 hours. Then place them in a tempering pool and temper them in tempering medium No. 1 at 80°C. Then place them in tempering medium No. 2 at room temperature for cooling. Example 3

[0019] Add 35 parts of water to 50 parts of PAG polymer, then heat to 34°C and stir at 100 r / min for 35 min. Then add 0.7 parts of stearamide polyoxyethylene ether phosphate, 0.4 parts of alkylolamide phosphate and 0.5 parts of sodium bicarbonate, then heat to 40°C and stir at 150 r / min for 10 min to obtain the quenching liquid.

[0020] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 9 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 530°C and hold for 60 minutes, then continue heating to 930°C and hold for 30 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 50°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 60°C and pH 10 and then dry them. (5) Heat the dried automotive alloy parts to 200°C and keep them warm for 3 hours. Then place them in a tempering pool and temper them in tempering medium No. 1 at 70°C. Then place them in tempering medium No. 2 for cooling. Example 4

[0021] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0022] The rest is the same as in Example 1. Example 5

[0023] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of lauryl alcohol polyoxyethylene ether and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0024] The rest is the same as in Example 1. Example 6

[0025] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 250 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0026] The rest is the same as in Example 1. Example 7

[0027] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 50 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0028] The rest is the same as in Example 1. Example 8

[0029] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 7.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling.

[0030] The rest is the same as in Example 1. Example 9

[0031] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling.

[0032] The rest is the same as in Example 1. Example 10

[0033] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 60°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling.

[0034] The rest is the same as in Example 1.

[0035] The automotive alloy parts prepared in Examples 1-10 were subjected to performance tests according to GB / T228.1-2010 and GB / T231.1-2018. The specific data are shown in Table 1.

[0036] Table 1 Performance parameter data of automotive alloy parts in each embodiment Example 1 272 992 843 Example 2 275 988 838 Example 3 270 989 836 Example 4 245 936 805 Example 5 241 934 806 Example 6 268 988 835 Example 7 271 986 833 Example 8 255 960 821 Example 9 252 954 820 Example 10 248 947 811 Table 1 shows that the hardness, tensile strength, and yield strength of the automotive alloy parts in Examples 1-3 were at the highest levels. Examples 4 and 5, which replaced stearamide polyoxyethylene ether phosphate and alkylolamide phosphate respectively, had the lowest performance parameters. The data for Examples 6 and 7 were very similar to those for Example 1, indicating that the stirring speed and stirring time in Example 1 were the optimal process parameters. The reason why the data for Example 8 was lower than that for Example 1 may be that the pH value of the cleaning agent was too low, resulting in incomplete cleaning of the stains on the surface of the automotive alloy parts, which in turn affected the quenching effect and the performance parameters of the automotive alloy parts. The reason why the data for Example 9 was lower than that for Example 1 may be that preheating was not performed before quenching, resulting in greater internal thermal stress in the automotive alloy parts, affecting the grain size, and thus affecting the performance parameters of the automotive alloy parts. The reason why the data for Example 10 was lower than that for Example 1 may be that the temperature of the quenching liquid was too high, reducing the cooling rate of the automotive alloy parts and causing problems such as incomplete phase transformation, which in turn affected the performance parameters of the automotive alloy parts. Example 11

[0037] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0038] The curing agent is obtained by mixing dithiol alkyltin and ethyl acetate at a mass ratio of 1:3.5.

[0039] Add 6 parts of alkyl salicylate molybdenum and 2 parts of silicone oil to 45 parts of polyurethane liquid resin, and stir at 350 r / min for 25 min. Then add 65 parts of boron nitride and 3 parts of hydroxyethyl methacrylate phosphate, and continue stirring for 35 min. Finally, add 4 parts of curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0040] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering pool and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature with added tempering medium supplement to cool them. Example 12

[0041] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0042] The curing agent is obtained by mixing dithioalkyltin and ethyl acetate in a mass ratio of 1:3.

[0043] Add 7 parts of lubricant alkyl salicylate molybdenum and 1 part of defoamer silicone oil to 40 parts of polyurethane liquid resin, and stir at 300 r / min for 30 min. Then add 60 parts of wear-resistant agent boron nitride and 4 parts of adhesion promoter hydroxyethyl methacrylate phosphate, and continue stirring for 40 min. Finally, add 3 parts of curing agent and continue stirring for 6 min to obtain tempering medium replenisher. (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering pool and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature with added tempering medium supplement to cool them. Example 13

[0044] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0045] The curing agent is obtained by mixing dithioalkyltin and ethyl acetate in a mass ratio of 1:4.

[0046] Add 5 parts of lubricant alkyl salicylate molybdenum and 3 parts of defoamer silicone oil to 50 parts of polyurethane liquid resin, and stir at 400 r / min for 20 min. Then add 70 parts of wear-resistant agent boron nitride and 2 parts of adhesion promoter hydroxyethyl methacrylate phosphate, and continue stirring for 30 min. Finally, add 5 parts of curing agent and continue stirring for 8 min to obtain tempering medium replenisher. (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering pool and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature with added tempering medium supplement to cool them. Example 14

[0047] The curing agent is obtained by mixing diphenylmethane diisocyanate and ethyl acetate at a mass ratio of 1:3.5.

[0048] The rest is the same as in Example 11. Example 15

[0049] Add 6 parts calcium stearate and 2 parts silicone oil to 45 parts polyurethane liquid resin, and stir at 350 r / min for 25 min. Then add 65 parts boron nitride and 3 parts hydroxyethyl methacrylate phosphate, and continue stirring for 35 min. Finally, add 4 parts curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0050] The rest is the same as in Example 11. Example 16

[0051] Add 6 parts of alkyl salicylate molybdenum and 2 parts of silicone oil to 45 parts of polyurethane liquid resin, and stir at 550 r / min for 25 min. Then add 65 parts of boron nitride and 3 parts of hydroxyethyl methacrylate phosphate, and continue stirring for 35 min. Finally, add 4 parts of curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0052] The rest is the same as in Example 11. Example 17

[0053] Add 6 parts of alkyl salicylate molybdenum and 2 parts of silicone oil to 45 parts of polyurethane liquid resin, and stir at 350 r / min for 40 min. Then add 65 parts of boron nitride and 3 parts of hydroxyethyl methacrylate phosphate, and continue stirring for 50 min. Finally, add 4 parts of curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0054] The rest is the same as in Example 11. Example 18

[0055] Add 6 parts of alkyl molybdenum salicylate, 2 parts of silicone oil, 65 parts of boron nitride, 3 parts of hydroxyethyl methacrylate phosphate, and 4 parts of curing agent to 45 parts of polyurethane liquid resin, and then stir at 350 r / min for 30 min to obtain tempering medium supplement.

[0056] The rest is the same as in Example 11. Example 19

[0057] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and cool them in tempering medium No. 2 at room temperature with added tempering medium supplement.

[0058] The rest is the same as in Example 11. Example 20

[0059] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling. (6) The cooled automotive alloy parts are coated with zinc by electroplating.

[0060] The rest is the same as in Example 11.

[0061] After cleaning the automotive alloy parts prepared in Examples 11-20 and preparing them into samples, their wear resistance was determined using an abrasion tester. The mass m1 before the test and the mass m2 after the test were measured, and the wear rate was calculated using the formula a=(m1-m2) / m1. The wear resistance was evaluated by the magnitude of the wear rate. Specific data are shown in Table 2.

[0062] Table 2. Wear resistance data of automotive alloy parts in Examples 11-20 Example 11 1.12 Example 12 1.17 Example 13 1.15 Example 14 5.74 Example 15 5.86 Example 16 4.18 Example 17 4.29 Example 18 5.45 Example 19 5.63 Example 20 1.18 Table 2 shows that Examples 11-13 had the lowest loss rates. The higher loss rate in Example 14 might be due to the replacement of dithiol alkyltin with diphenylmethane diisocyanate, causing premature curing of the polyurethane liquid resin. This resulted in the resin curing before tempering was complete, thus affecting wear resistance. The higher loss rate in Example 15 might be due to the replacement of alkyl salicylate molybdenum with calcium stearate. Calcium stearate does not possess the characteristic of alkyl salicylate molybdenum decomposing at high temperatures to enhance wear resistance. The higher loss rate in Example 16 might be due to excessively fast stirring speed, which introduced air into the resin. These air bubbles, after curing, would affect wear resistance. Example 17 loss rate... The high wear rate in Example 18 may be due to excessive stirring time, which introduces air and may cause resin particles to agglomerate, thus affecting wear resistance. The high wear rate in Example 19 may be due to the lack of secondary tempering, which causes premature resin curing and thermal stress, thus affecting wear resistance. Example 20 uses a conventional electroplated metal coating, and its wear rate is similar to that of Example 11, indicating that the method of the present invention can achieve wear resistance similar to that of electroplated metal coating. Example 21

[0063] Add 4 parts butylated hydroxyanisole, 0.4 parts tributyl phosphate, 12 parts hydrogenated methyl rosinate and 9 parts hydrogenated castor oil isostearate to 55 parts 150BS bright oil, then heat to 50℃ and stir at 150 r / min for 2 hours. After stirring, the tempering medium is obtained.

[0064] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0065] The curing agent is obtained by mixing dithiol alkyltin and ethyl acetate at a mass ratio of 1:3.5.

[0066] Add 6 parts of alkyl salicylate molybdenum and 2 parts of silicone oil to 45 parts of polyurethane liquid resin, and stir at 350 r / min for 25 min. Then add 65 parts of boron nitride and 3 parts of hydroxyethyl methacrylate phosphate, and continue stirring for 35 min. Finally, add 4 parts of curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0067] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling. Example 22

[0068] Add 5 parts butylated hydroxyanisole, 0.3 parts tributyl phosphate, 14 parts hydrogenated methyl rosinate and 8 parts hydrogenated castor oil isostearate to 50 parts 150BS bright oil, then heat to 45℃ and stir at 200 r / min for 1.5 h. After stirring, the tempering medium is obtained.

[0069] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0070] The curing agent is obtained by mixing dithiol alkyltin and ethyl acetate at a mass ratio of 1:3.5.

[0071] Add 6 parts of alkyl salicylate molybdenum and 2 parts of silicone oil to 45 parts of polyurethane liquid resin, and stir at 350 r / min for 25 min. Then add 65 parts of boron nitride and 3 parts of hydroxyethyl methacrylate phosphate, and continue stirring for 35 min. Finally, add 4 parts of curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0072] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling. Example 23

[0073] Add 3 parts butylated hydroxyanisole, 0.5 parts tributyl phosphate, 10 parts hydrogenated methyl rosinate and 10 parts hydrogenated castor oil isostearate to 60 parts 150BS bright oil, then heat to 55℃ and stir at 100 r / min for 2.5 h. After stirring, the tempering medium is obtained.

[0074] Add 40 parts of water to 45 parts of PAG polymer, then heat to 32°C and stir at 125 r / min for 30 min. Then add 0.6 parts of stearamide polyoxyethylene ether phosphate, 0.5 parts of alkylolamide phosphate and 0.6 parts of sodium bicarbonate, then heat to 43°C and stir at 125 r / min for 15 min to obtain the quenching liquid.

[0075] The curing agent is obtained by mixing dithiol alkyltin and ethyl acetate at a mass ratio of 1:3.5.

[0076] Add 6 parts of alkyl salicylate molybdenum and 2 parts of silicone oil to 45 parts of polyurethane liquid resin, and stir at 350 r / min for 25 min. Then add 65 parts of boron nitride and 3 parts of hydroxyethyl methacrylate phosphate, and continue stirring for 35 min. Finally, add 4 parts of curing agent and continue stirring for 7 min to obtain the tempering medium supplement.

[0077] (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8.5 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 550°C and hold for 55 minutes, then continue heating to 925°C and hold for 35 minutes; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 45°C, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 65°C and pH 9.5 and then dry them. (5) Heat the dried automotive alloy parts to 190°C and keep them warm for 3.5 hours. Then place them in a tempering bath and temper them in tempering medium No. 1 at 75°C. Then place them in tempering medium No. 2 at room temperature for cooling. Example 24

[0078] Add 4 parts butylated hydroxyanisole, 0.4 parts tributyl phosphate, 12 parts polymethyl methacrylate and 9 parts hydrogenated castor oil isostearate to 55 parts 150BS bright oil, then heat to 50℃ and stir at 150 r / min for 2 hours. After stirring, the tempering medium is obtained.

[0079] The rest is the same as in Example 21. Example 25

[0080] Add 4 parts butylated hydroxyanisole, 0.4 parts tributyl phosphate, 12 parts methyl rosinate and 9 parts cetyl alcohol to 55 parts 150BS bright oil, then heat to 50℃ and stir at 150 r / min for 2 hours. After stirring, the tempering medium is obtained.

[0081] The rest is the same as in Example 21. Example 26

[0082] Add 4 parts butylated hydroxyanisole, 0.4 parts tributyl phosphate, 12 parts hydrogenated methyl rosinate and 9 parts hydrogenated castor oil isostearate to 55 parts 150BS bright oil, then heat to 80℃ and stir at 150 r / min for 2 hours. After stirring, the tempering medium is obtained.

[0083] The rest is the same as in Example 21. Example 27

[0084] Add 4 parts butylated hydroxyanisole, 0.4 parts tributyl phosphate, 12 parts hydrogenated methyl rosinate and 9 parts hydrogenated castor oil isostearate to 55 parts 150BS bright oil, then heat to 50℃ and stir at 300r / min for 2h. After stirring, the tempering medium is obtained.

[0085] The rest is the same as in Example 21. Example 28

[0086] This embodiment uses existing technology to perform quenching and tempering processes on automotive alloy parts.

[0087] The hardness and impact toughness of the automotive alloy parts prepared in Examples 11 and 21-28 were measured. The hardness-toughness ratio was calculated using the formula b=Y / R, where b is the hardness-toughness ratio, Y is the hardness, and R is the impact toughness. Meanwhile, 200 sets of different threads were mechanically and automatically installed on the automotive alloy parts to observe whether there was any stripping of the threads. The specific data are shown in Table 3.

[0088] Table 3 Performance table of automotive alloy parts in Examples 21-28 Example 11 277 59 4.69 7 Example 21 236 92 2.57 1 Example 22 229 90 2.54 1 Example 23 234 89 2.63 1 Example 24 249 70 3.56 3 Example 25 251 74 3.39 3 Example 26 244 80 3.05 2 Example 27 240 76 3.16 2 Example 28 263 65 4.05 5 Table 3 shows that Examples 21-23 have lower hardness and higher impact toughness compared to other examples. Furthermore, no stripping occurred when matched with threads of five different hardnesses, indicating that after tempering and cooling, the hardness-to-toughness ratio of automotive parts can be controlled within a certain range, thereby increasing their applicability, reducing installation defects and rework rates, and improving production efficiency. Example 11 did not use tempering and cooling, therefore it had the highest hardness-to-toughness ratio, but also the highest number of stripping occurrences. Although Examples 24 and 25 had higher hardness, their impact toughness was also lower. The small hardness results in a relatively large hardness-to-toughness ratio, which significantly increases the number of slippages when matched with threads of different hardness. Although the hardness of Examples 26 and 27 is not large, their impact toughness is also small, resulting in a larger hardness-to-toughness ratio, which in turn leads to slippage. Example 28 uses existing technology to treat automotive alloy parts, and its hardness-to-toughness ratio is lower than that of Example 11 but higher than that of other examples. Its number of slippages is only lower than that of Example 11, indicating that the hardness-to-toughness ratio of automotive alloy parts treated with tempering cooling medium is significantly improved, and the number of installation defects such as slippage is reduced.

Claims

1. A post-processing method for enhancing the performance of automotive alloy parts, characterized in that: The specific steps are as follows: (1) Load the automotive alloy parts, and use a cleaning agent with a pH value of 8~9 for pre-cleaning and then drying; (2) Heat the dried automotive alloy parts to 530~570℃ and hold for 50~60min, then continue heating to 920~930℃ and hold for 30~40min; (3) Place the insulated automotive alloy parts into a quenching tank and quench them in a quenching liquid at 40~50℃, then cool them. (4) Clean the cooled automotive alloy parts with a cleaning agent at 60-70℃ and pH 9-10 and then dry them. (5) Heat the dried automotive alloy parts to 180~200℃ and keep them warm for 3~4 hours. Then place them in a tempering tank and temper them in tempering medium No. 1 at a temperature of 70~80℃. Then place them in tempering medium No. 2 at a temperature of room temperature for cooling. The preparation method of the quenching fluid is as follows: Add 35-45 parts of water to 40-50 parts of PAG polymer, then heat to 30-34℃ and stir at 100-150 r / min for 25-35 min. Then add 0.5-0.7 parts of stearamide polyoxyethylene ether phosphate, 0.4-0.6 parts of alkylolamide phosphate and 0.5-0.7 parts of sodium bicarbonate. Then heat to 40-45℃ and stir at 100-150 r / min for 10-20 min to obtain the quenching liquid. The No. 2 tempering medium also includes a tempering medium replenisher, which is prepared by the following method: Add 5-7 parts of lubricant alkyl salicylate molybdenum and 1-3 parts of defoamer silicone oil to 40-50 parts of polyurethane liquid resin, and stir at 300-400 r / min for 20-30 min. Then add 60-70 parts of wear-resistant agent boron nitride and 2-4 parts of adhesion promoter hydroxyethyl methacrylate phosphate, and continue stirring for 30-40 min. Finally, add 3-5 parts of curing agent and continue stirring for 6-8 min to obtain tempering medium replenisher. The curing agent is obtained by mixing dithiol alkyltin and ethyl acetate in a mass ratio of 1:3~4. The tempering medium is: Add 3-5 parts of antioxidant butylated hydroxyanisole, 0.3-0.5 parts of defoamer tributyl phosphate, 10-14 parts of hydrogenated methyl rosinate, and 8-10 parts of hydrogenated castor oil isostearate to 50-60 parts of 150BS bright oil. Then heat to 45-55℃ and stir at 100-200 r / min for 1.5-2.5 h. After stirring, the tempering medium is obtained.

2. The post-processing method for enhancing the performance of automotive alloy parts as described in claim 1, characterized in that: The automotive alloy parts include stamped parts, welded parts, and threaded connection alloy parts.