Heat treatment method of disc spring and obtained disc spring

Abstract

The invention provides a heat treatment method of a disc spring and the obtained disc spring, and belongs to the technical field of disc spring preparation. The heat treatment method of the disc spring comprises the following steps that (1) the surface of the disc spring is cleaned, and the cleaned disc spring is obtained; (2) the surface of the cleaned disc spring is coated with a coating and dried, and the disc spring coated with the coating is obtained; (3) the disc spring coated with the coating is subjected to heat treatment, and the disc spring subjected to heat treatment is obtained; and (4) after the disc spring subjected to heat treatment is cooled to the room temperature, the coating is removed. After the heat treatment method provided by the invention is used for treating the disc spring, the disc spring can be uniformly heated without cracks in the heat treatment process, and the pressure value of the disc spring is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of disc spring preparation, and in particular relates to a heat treatment method for a disc spring and the obtained disc spring. Background Art

[0002] Disc springs, also known as Belleville spring washers, are conical discs that can be used individually or in series or in parallel. They bear static or dynamic loads acting in the axial direction at the upper inner edge and the lower outer edge. They are deformed after being compressed until they are flattened, storing energy as live loads. Disc springs bear large loads in a small space and are widely used in heavy machinery and equipment (such as large forging and pressing machines, boiler hangers, etc.), aerospace, shipbuilding and other fields as strong buffers and vibration damping springs.

[0003] At present, the processing route of disc springs is generally: cutting-wire cutting-stamping-heat treatment-turning-strong pressure-coloring and penetration. In the process of disc spring processing, whether the heat treatment is evenly heated and crack-free is the key to the disc spring to obtain excellent pressure value performance. However, since the thickness of the disc spring is generally 1mm, it is very easy to crack. The most direct impact is the cracks in the disc spring after heat treatment, the disc spring has a decarburization layer that exceeds the standard, and the performance enhancement effect of the heat treatment is lost. The performance capacity of the disc spring deteriorates, and ultimately causes material failure and part performance degradation during the pressure experiment. Therefore, obtaining a heat treatment method without decarburization layer, black oxide layer, cracks, and heat treatment is crucial to improving the pressure performance of the disc spring. Summary of the invention

[0004] In view of this, the present invention provides a heat treatment method for a disc spring. After the disc spring is treated by the heat treatment method provided by the present invention, the disc spring can be heated evenly during the heat treatment process without cracks, and the pressure value of the disc spring is excellent.

[0005] The present invention provides a heat treatment method for a disc spring, comprising the following steps:

[0006] 1) Cleaning the surface of the disc spring to obtain a cleaned disc spring;

[0007] 2) coating the cleaned disc spring surface with paint and drying the coating to obtain a disc spring covered with a coating;

[0008] 3) heat treating the disc spring covered with the coating to obtain a heat-treated disc spring;

[0009] 4) After the disc spring has cooled to room temperature after heat treatment, remove the coating.

[0010] Preferably, the cleaning in step 1) comprises the following steps:

[0011] a. Use alcohol to clean the surface of the parts to remove the oil stains attached during the surface processing;

[0012] b. Grind the surface of parts to remove rust and / or oxide layer;

[0013] c. Use compressed air to blow the inner and outer surfaces of parts.

[0014] Preferably, the coating in step 2) is an anti-oxidation and anti-decarburization coating.

[0015] Preferably, the thickness of the coating in step 2) is 0.2 to 1.2 mm.

[0016] Preferably, the coating in step 2) is carried out in the following manner:

[0017] (1) Tie the disc spring with low-carbon galvanized steel wire and completely immerse it in a container filled with paint. Move the disc spring up and down or axially during the dipping process;

[0018] (2) Take out the disc spring after 2 to 3 minutes of dipping and hang it in the shade to dry naturally.

[0019] Preferably, after shade drying, the workpiece is dried at 75-85° C. for 1.5-2.5 h, and then dried at 155-165° C. for 0.5-1.5 h.

[0020] Preferably, the process parameters for heat treatment in step 3) are: quenching temperature 855-865° C., time 10-15 min; tempering temperature 420-430° C., time 20-30 min.

[0021] Preferably, the coating is removed in step 4) by soaking the disc spring in a hot water tank filled with hot water above 70° C. until the coating attached to the surface of the disc spring falls off.

[0022] Preferably, the disc spring is made of material 60Si2MnA.

[0023] The present invention provides a disc spring obtained by any one of the above-mentioned heat treatment methods, wherein the pressure value of the disc spring is 880 to 1000N.

[0024] Compared with the prior art, the advantages and positive effects of the present invention are:

[0025] The present invention provides a method for heat treatment of disc springs. First, a layer of coating is coated on the surface of the disc spring. The coating can protect the surface of the heat-treated parts. The coating can isolate the surface of the parts from contact with air during the heat treatment. There is no black oxide layer on the surface of the parts during the heat treatment. Further, heat treatment is performed by setting reasonable process parameters to obtain a disc spring with a high pressure value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1This is a schematic diagram of the disc spring surface after coating;

[0027] Figure 2 A schematic diagram of detecting whether there are cracks in the disc spring after heat treatment. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0029] The present invention provides a heat treatment method for a disc spring, comprising the following steps:

[0030] 1) Cleaning the surface of the disc spring to obtain a cleaned disc spring;

[0031] 2) coating the cleaned disc spring surface with paint and drying the coating to obtain a disc spring covered with a coating;

[0032] 3) heat treating the disc spring covered with the coating to obtain a heat-treated disc spring;

[0033] 4) After the disc spring has cooled to room temperature after heat treatment, remove the coating.

[0034] The present invention cleans the surface of the disc spring to obtain the cleaned disc spring. In the present invention, the disc spring is preferably made of material 60Si2MnA.

[0035] In the present invention, the cleaning preferably comprises the following steps:

[0036] a. Use alcohol to clean the surface of the parts to remove the oil stains attached during the surface processing;

[0037] b. Grind the surface of parts to remove rust and / or oxide layer;

[0038] c. Use compressed air to blow the inner and outer surfaces of parts.

[0039] In the present invention, the workpiece is thoroughly degreased and rusted by cleaning, and dust and other stains are removed by blowing with compressed air, thereby preventing the dirt on the surface of the workpiece from causing peeling or bubbles to occur during the subsequent drying process after coating, thereby affecting the anti-oxidation effect.

[0040] After obtaining the cleaned disc spring, the present invention applies a coating on the surface of the cleaned disc spring and dries it to obtain a disc spring covered with a coating. In the present invention, the coating is preferably an anti-oxidation and anti-decarburization coating. The coating used in the embodiment of the present invention is the "202 anti-high temperature and anti-decarburization coating" of Zhejiang Huangyan Coating Co., Ltd.

[0041] In the present invention, the coating is preferably carried out in the following manner:

[0042] (1) Tie the disc spring with low-carbon galvanized steel wire and completely immerse it in a container filled with paint. Move the disc spring up and down or axially during the dipping process;

[0043] (2) Take out the disc spring after dipping for 2 to 3 minutes and hang it in the shade to dry naturally.

[0044] In the present invention, before applying the coating, the coating is preferably stirred with a stirring rod, and then the stirring rod is lifted for inspection. The coating should be evenly and finely attached to the stirring rod without lumps or particles. In the present invention, the coating is preferably stirred again before dipping, so that not only the coating can be made uniform, but also residual bubbles in the coating can be removed. In the present invention, the disc spring is moved up and down or axially during the dipping process to prevent small bubbles in the coating from being adsorbed on the parts.

[0045] In the present invention, the disc spring is taken out after 2 to 3 minutes of dipping, and the dipped disc spring is hung to dry naturally in the shade. After drying in the shade, the workpiece is preferably dried at 75 to 85°C for 1.5 to 2.5 hours, and then dried at 155 to 165°C for 0.5 to 1.5 hours. In the present invention, the drying time is preferably 2 hours. In the present invention, by first drying in the shade naturally and then drying, it is beneficial to fully dry the coating, and the coating on the surface of the parts is not easy to crack and fall off. In the present invention, the thickness of the coating is preferably 0.2 to 1.2 mm, and more preferably 0.3 to 0.8 mm. A coating that is too thick will easily crack when drying and lose its protective effect, while a coating that is too thin will not effectively play a protective role. It can be understood that the coating thickness specified in the present invention is the optimal thickness. After the disc spring surface is coated with paint, Figure 1 In the present invention, the coating should be free of defects such as missing coating, scratches, cracks, small bubbles, etc. If there are any of the above defects, a brush dipped in an appropriate amount of paint can be used to brush and repair them.

[0046] The present invention coats the surface of the disc spring with a coating, and the coating can protect the surface of the heat-treated part. The coating can isolate the surface of the part from contact with the air during the heat treatment, and there is no black oxide layer on the surface of the part during the heat treatment.

[0047] After obtaining the disc spring covered with the coating, the present invention performs heat treatment on the disc spring covered with the coating to obtain the disc spring after heat treatment. In the present invention, the process parameters during heat treatment are preferably: quenching temperature 855-865°C, time 10-15min; tempering temperature 420-430°C, time 20-30min. When the heat treatment process parameter heat treatment temperature is higher than 880°C, the parts will produce cracks and overburning; the heat treatment temperature is lower than 830°C, the hardness value of the parts does not meet the requirements, and the pressure value does not meet the requirements. It can be understood that the heat treatment process parameters provided by the present invention can obtain products without cracks, good hardness and high pressure values.

[0048] After obtaining the heat-treated disc spring, the present invention cools the heat-treated disc spring to room temperature and removes the coating. In the present invention, the coating removal method is preferably: the disc spring is placed in a hot water tank filled with hot water above 70°C for soaking until the coating attached to the surface of the disc spring falls off. The present invention uses the penetration method to perform quality inspection on the heat-treated disc spring. Figure 2 As shown in the figure, the disc spring is tested for cracks using the color penetration method. The test results show that the test piece has no cracks.

[0049] The heat treatment method provided by the present invention first protects the surface of the part by coating a coating on the surface of the disc spring. During the heating process, the coating forms a dense and firm substance that adheres to the surface of the steel material, so that the steel material is isolated from the air, thereby preventing the disc spring from oxidation and decarburization. In the original state, the coating is composed of evenly dispersed solid particles physically connected by an adhesive and is in a relatively loose state. At this time, the coating is thicker and more uniform, and there are no obvious defects such as pores and cracks. During the heat treatment process, as the temperature rises, the coating is gradually dehydrated and dried, the low-temperature components begin to decompose, the organic matter volatilizes, and the coating thickness begins to decrease. At this time, pores appear in the coating and it begins to be porous. The appearance of the porous stage makes it impossible for the coating to completely avoid the oxidation of the steel material, but can only reduce its degree of oxidation. When the temperature continues to rise, the pore size of the coating gradually decreases and the density of the coating increases. When the coating reaches the softening temperature of 705°C, the porosity decreases sharply. When the temperature rises to 900℃, the coating begins to melt to form a continuous, dense, moderately viscous tetrahedron network structure as the skeleton. Each tetrahedron is connected by corner vertices to form a three-dimensional network structure, in which low-temperature components such as alkali metal oxides are filled in the holes of the grid structure in liquid form, thus forming a dense gas barrier layer, which effectively prevents the contact between the high-temperature furnace gas and the steel surface, and achieves the purpose of protecting the substrate. It can make the disc spring evenly heated during the heat treatment process without cracks, and further heat treatment by setting reasonable process parameters can obtain a high-pressure disc spring.

[0050] The present invention provides a disc spring obtained by any one of the heat treatment methods described above, wherein the pressure value of the disc spring is 880 to 1000N.

[0051] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0052] Example 1

[0053] Use cotton yarn dipped in alcohol to clean the disc spring surface and remove the oil and other dirt attached during the surface processing. Use fine sandpaper to polish the disc spring surface to remove the surface rust and oxide layer, and then use cotton cloth to wipe the cleaned disc spring surface again. Use compressed air to blow the inner and outer surfaces of the disc spring to remove the attached dust and other stains to obtain the cleaned disc spring.

[0054] Stir the coating evenly, tie the cleaned disc spring with low-carbon galvanized steel wire, and immerse it in the coating. Move the disc spring up and down or axially during the dipping process. Take out the disc spring after 2 minutes of dipping. The coating thickness is 0.3mm. Check that the coating should be evenly attached to the surface of the disc spring. Then hang the dipped disc spring to dry naturally in the shade for 2 hours. After drying in the shade, transfer it to an oven and dry it at 80℃ for 2 hours and 160℃ for 1 hour to obtain a disc spring covered with a coating.

[0055] Place the disc spring with coating in a basket and push it steadily into a medium-temperature box furnace for aging treatment. During the furnace loading process, be careful to prevent the disc springs from bumping against each other and damaging the surface coating. The process parameters for heat treatment are preferably: quenching temperature 865℃, time 12min; tempering temperature 430℃, time 30min. After the disc spring cools naturally to room temperature, soak it in a 80℃ hot water tank until the coating attached to the surface of the disc spring falls off. Wipe the inner and outer surfaces of the disc spring with cotton cloth to remove the paint residue remaining on the surface of the disc spring.

[0056] Example 2

[0057] Use cotton yarn dipped in alcohol to clean the disc spring surface and remove the oil and other dirt attached during the surface processing. Use fine sandpaper to polish the disc spring surface to remove the surface rust and oxide layer, and then use cotton cloth to wipe the cleaned disc spring surface again. Use compressed air to blow the inner and outer surfaces of the disc spring to remove the attached dust and other stains to obtain the cleaned disc spring.

[0058] Stir the coating evenly, tie the cleaned disc spring with low-carbon galvanized steel wire, and immerse it in the coating. Move the disc spring up and down or axially during the dipping process. Take out the disc spring after 3 minutes of dipping. The coating thickness is 0.6mm. Check that the coating should be evenly attached to the surface of the disc spring. Then hang the dipped disc spring to dry naturally in the shade for 2 hours. After drying in the shade, transfer it to an oven and dry it at 75℃ for 2.5 hours and 165℃ for 0.5 hour to obtain a disc spring covered with a coating.

[0059] Place the disc spring with coating in a basket and push it steadily into a medium-temperature box furnace for aging treatment. During the furnace loading process, be careful to prevent the disc springs from bumping against each other and damaging the surface coating. The process parameters for heat treatment are preferably: quenching temperature 855℃, time 15min; tempering temperature 425℃, time 20min. After the disc spring cools naturally to room temperature, soak it in a 80℃ hot water tank until the coating attached to the surface of the disc spring falls off. Wipe the inner and outer surfaces of the disc spring with cotton cloth to remove the paint residue remaining on the surface of the disc spring.

[0060] Example 3

[0061] Use cotton yarn dipped in alcohol to clean the disc spring surface and remove the oil and other dirt attached during the surface processing. Use fine sandpaper to polish the disc spring surface to remove the surface rust and oxide layer, and then use cotton cloth to wipe the cleaned disc spring surface again. Use compressed air to blow the inner and outer surfaces of the disc spring to remove the attached dust and other stains to obtain the cleaned disc spring.

[0062] Stir the coating evenly, tie the cleaned disc spring with low-carbon galvanized steel wire, and immerse it in the coating. Move the disc spring up and down or axially during the dipping process. Take out the disc spring after 3 minutes of dipping. The coating thickness is 0.8mm. Check that the coating should be evenly attached to the surface of the disc spring. Then hang the dipped disc spring to dry naturally in the shade for 2 hours. After drying in the shade, transfer it to an oven and dry it at 85℃ for 1.5 hours and 155℃ for 1.5 hours to obtain a disc spring covered with a coating.

[0063] Place the disc spring with coating in a basket and push it steadily into a medium-temperature box furnace for aging treatment. During the furnace loading process, be careful to prevent the disc springs from bumping against each other and damaging the surface coating. The process parameters for heat treatment are preferably: quenching temperature 860℃, time 10min; tempering temperature 420℃, time 25min. After the disc spring cools naturally to room temperature, soak it in a 80℃ hot water tank until the coating attached to the surface of the disc spring falls off. Wipe the inner and outer surfaces of the disc spring with cotton cloth to remove the paint residue remaining on the surface of the disc spring.

[0064] Comparative Example 1

[0065] The difference from Example 1 is that no coating is applied. The specific preparation process is as follows:

[0066] Use cotton yarn dipped in alcohol to clean the disc spring surface and remove the oil and other dirt attached during the surface processing. Use fine sandpaper to polish the disc spring surface to remove the surface rust and oxide layer, and then use cotton cloth to wipe the cleaned disc spring surface again. Use compressed air to blow the inner and outer surfaces of the disc spring to remove the attached dust and other stains to obtain the cleaned disc spring.

[0067] Place the cleaned disc spring in a basket and push it steadily into a medium-temperature box furnace for aging treatment. During the furnace loading process, be careful to prevent the disc springs from bumping against each other and damaging the surface coating. The preferred process parameters for heat treatment are: quenching temperature 865℃, time 12min; tempering temperature 430℃, time 30min.

[0068] Comparative Example 2

[0069] The difference from Example 1 is that the process parameters during heat treatment are different. The specific operation is as follows:

[0070] Use cotton yarn dipped in alcohol to clean the disc spring surface and remove the oil and other dirt attached during the surface processing. Use fine sandpaper to polish the disc spring surface to remove the surface rust and oxide layer, and then use cotton cloth to wipe the cleaned disc spring surface again. Use compressed air to blow the inner and outer surfaces of the disc spring to remove the attached dust and other stains to obtain the cleaned disc spring.

[0071] Stir the coating evenly, tie the cleaned disc spring with low-carbon galvanized steel wire, and immerse it in the coating. Move the disc spring up and down or axially during the dipping process. Take out the disc spring after 2 minutes of dipping. The coating thickness is 0.3mm. Check that the coating should be evenly attached to the surface of the disc spring. Then hang the dipped disc spring to dry naturally in the shade for 2 hours. After drying in the shade, transfer it to an oven and dry it at 80℃ for 2 hours and 160℃ for 1 hour to obtain a disc spring covered with a coating.

[0072] Place the disc spring with coating in a basket and push it steadily into a medium-temperature box furnace for aging treatment. During the furnace loading process, be careful to prevent the disc springs from bumping against each other and damaging the surface coating. The process parameters for heat treatment are preferably: quenching temperature 800℃, time 12min; tempering temperature 400℃, time 30min. After the disc spring cools naturally to room temperature, put it in an 80℃ hot water tank for soaking until the coating attached to the surface of the disc spring falls off. Wipe the inner and outer surfaces of the disc spring with cotton cloth to remove the paint residue remaining on the surface of the disc spring.

[0073] Performance Testing

[0074] The disc springs prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were tested respectively, and the specific results are shown in Table 1.

[0075] Table 1 Performance test results of disc spring

[0076]

[0077] It can be seen from Table 1 that by first coating the surface of the disc spring with paint, the surface protection requirements of the parts can be met, and further heat treatment is performed by setting reasonable process parameters to obtain a disc spring with a high pressure value.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for heat treatment of a disc spring, characterized in that: The steps include: 1) Cleaning the surface of the disc spring to obtain a cleaned disc spring; 2) coating the cleaned disc spring surface with paint and drying it to obtain a disc spring covered with a coating; 3) heat treating the disc spring covered with the coating to obtain a disc spring after heat treatment; 4) After the disc spring has cooled to room temperature after heat treatment, remove the coating.

2. The heat treatment method according to claim 1, characterized in that The cleaning in step 1) comprises the following steps: a. Use alcohol to clean the surface of the parts to remove the oil stains attached during the surface processing; b. Grind the surface of parts to remove rust and / or oxide layer; c. Use compressed air to blow the inner and outer surfaces of parts.

3. The heat treatment method according to claim 1, characterized in that The coating in step 2) is an anti-oxidation and anti-decarburization coating.

4. The heat treatment method according to claim 1, characterized in that: The thickness of the coating in step 2) is 0.2 to 1.2 mm.

5. The heat treatment method according to claim 1, characterized in that: The coating in step 2) is carried out in the following manner: (1) Tie the disc spring with low-carbon galvanized steel wire and completely immerse it in a container filled with paint. Move the disc spring up and down or axially during the dipping process; (2) Take out the disc spring after dipping for 2 to 3 minutes and hang it in the shade to dry naturally.

6. The heat treatment method according to claim 5, characterized in that: After drying in the shade, dry the workpiece at 75-85°C for 1.5-2.5 hours, and then dry it at 155-165°C for 0.5-1.5 hours.

7. The heat treatment method according to claim 1, characterized in that: The process parameters for heat treatment in step 3) are: quenching temperature 855-865° C., time 10-15 min; tempering temperature 420-430° C., time 20-30 min.

8. The heat treatment method according to claim 1, characterized in that: The method of removing the coating in step 4) is: put the disc spring into a hot water tank filled with hot water above 70° C. and soak it until the coating attached to the surface of the disc spring falls off.

9. The heat treatment method according to claim 1, characterized in that: The disc spring is made of material 60Si2MnA.

10. The disc spring obtained by the heat treatment method according to any one of claims 1 to 9, characterized in that: The pressure value of the disc spring is 880-1000N.

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