A method for manufacturing brake disc metal disc body based on FNC processing

Abstract

This invention discloses a manufacturing method for brake disc metal bodies based on FNC (Fatigue-Neutralization) treatment, relating to the field of brake disc manufacturing technology. The specific operations of this FNC-based brake disc metal body manufacturing method are as follows: S1, stress relief treatment is performed on the brake disc body to eliminate stress during the brake disc casting and machining process; the brake disc body is then machined according to production needs; S2, the brake disc body is transferred to an oxidation furnace, and the furnace pressure is evacuated. Simultaneously, nitrogen is used to balance the furnace pressure, ensuring that the furnace pressure remains within a safe range. This FNC-based brake disc metal body manufacturing method, by adding an impregnation aid followed by high-temperature pressure application, uses a mixture of molten titanium oxide and iron oxide red as the pressure and heat transfer medium. The sudden increase in surface temperature while applying pressure further enhances fatigue strength and wear resistance, improving product quality while meeting user requirements.

Description

Technical Field

[0001] This invention relates to the field of brake disc manufacturing technology, specifically to a method for manufacturing a brake disc metal disc body based on FNC processing. Background Technology

[0002] A brake is a device that decelerates, stops, or keeps a moving part (or moving machinery) at a stop. It is also a mechanical part that stops or decelerates moving parts in machinery. Commonly known as a brake or decelerator. Except for various retarding devices, almost all automotive brakes utilize friction between the working surfaces of a fixed element and a rotating element to generate braking torque. Currently, friction brakes widely used in various types of automobiles can be divided into two main categories based on the different rotating elements: drum brakes and disc brakes. The difference between them is that the rotating element in a drum brake friction pair is a brake drum, with its cylindrical surface as the working surface; while the rotating element in a disc brake friction pair is a disc-shaped brake disc, with its end face as the working surface.

[0003] Carbonitriding (FNC), also known as nitrocarburizing, is a chemical surface heat treatment process that simultaneously diffuses carbon and nitrogen into the surface of steel parts. It primarily involves carburizing, with a small amount of nitrogen diffused in. Because early carbonitriding processes used percyanate salts or cyanide-containing atmospheres as diffusion agents, it was also called "cyaniding." Based on the state of the diffusion medium, it is classified into three types: gaseous, liquid, and solid. Solid and liquid carbonitriding are rarely used nowadays. Gas carbonitriding does not use cyanate salts, making it easier to control surface quality and allowing for mechanization and automation, thus it is more widely used. Compared to carburizing, it has advantages such as faster diffusion rate, higher hardenability and tempering resistance of the diffused layer, better wear resistance and fatigue resistance, and a lower processing temperature, often used as a substitute for carburizing.

[0004] In existing technologies, the brake disc body is processed by performing two oxidation operations (pre-oxidation and post-oxidation) during the component cooling process, while carbon dioxide, nitrogen and ammonia are introduced between the two oxidation operations (the compounds may vary depending on the actual needs, but carbon dioxide, nitrogen and ammonia are the most commonly used in brake disc manufacturing). Although this increases fatigue strength and wear resistance compared to brake discs produced without FNC treatment, the performance increase is not significant and still cannot adequately meet the user's needs. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a method for manufacturing brake disc metal bodies based on FNC treatment. This method solves the problem in existing technologies where the brake disc body is processed by performing two oxidation operations (pre-oxidation and post-oxidation) during the component cooling process, while simultaneously introducing carbon dioxide, nitrogen, and ammonia between the two oxidation operations (the compounds may vary depending on the actual needs; currently, carbon dioxide, nitrogen, and ammonia are the most commonly used in brake disc manufacturing). Although this method increases fatigue strength and wear resistance compared to brake discs produced without FNC treatment, the performance improvement is not significant and still fails to adequately meet user requirements.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for manufacturing a brake disc metal disc body based on FNC processing, the specific operation of which is as follows:

[0009] S1. Perform stress relief treatment on the brake disc body to eliminate the stress during the casting and machining process of the brake disc, and perform mechanical processing on the brake disc body according to production needs.

[0010] S2. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. At the same time, use nitrogen to balance the furnace pressure so that the furnace pressure is within a safe range.

[0011] S3. Perform pre-oxidation treatment on the brake disc body in the oxidation path.

[0012] S4. Perform nitriding and carbonitriding (FNC) treatment, as follows:

[0013] S41. Transfer the brake disc body to the nitriding furnace;

[0014] S42. Introduce carbon dioxide and nitrogen. During the introduction process, the temperature should be maintained between 550-560℃. After the gas pressure inside the nitriding furnace stabilizes, proceed to the next step.

[0015] S43. Introduce ammonia gas. After the introduction is complete, continue to maintain the ammonia gas for 1.5-4.5 hours before proceeding to the next step.

[0016] S5. Prepare the auxiliary agent. The raw materials for the auxiliary agent are titanium oxide powder and iron oxide red powder. The mass ratio of titanium oxide powder to iron oxide red powder is 1:3-1:4. Heat the auxiliary powder to 1600-1700℃ to make it melt and set aside.

[0017] S6. Remove the brake disc body from the nitriding furnace, and then immerse the brake disc body in the molten auxiliary agent obtained in step S5 for 1-3 minutes.

[0018] S7. Apply high-temperature pressure to the brake disc body. The pressure surface of the pressure mechanism is in contact with the surface of the brake disc body. Before applying pressure, the pressure surface needs to be heated to 1000-1100℃. The pressure intensity is 4-6 kPa. The pressure operation lasts for 5-10 minutes.

[0019] S8. Perform a cooling operation to reduce the surface temperature of the brake disc to 430-440℃ within 10 minutes.

[0020] S9. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. While evacuating the furnace, use nitrogen to balance the furnace pressure so that the pressure inside the furnace is within a safe range.

[0021] S10. Perform post-oxidation treatment on the brake disc body in the oxidation path;

[0022] S11. Remove the brake disc body and perform subsequent additional processing operations on the brake disc body according to actual production needs.

[0023] Preferably, in step S3, the temperature of the pre-oxidation treatment is 400-410°C, the duration is 45-55 min, and the brake disc body is oxidized using a mixture of water and an oxidizing agent.

[0024] Preferably, in step S4, the pressure inside the nitriding furnace must be maintained between 18-22 kPa.

[0025] Preferably, in step S4, the total amount of ammonia, carbon dioxide, and nitrogen is determined according to actual production needs, and the volume ratio of ammonia, carbon dioxide, and nitrogen is 10:1:9.

[0026] Preferably, in step S10, the temperature of the post-oxidation treatment is 400-410℃, the duration is 45-55 min, and the brake disc body is oxidized using a mixture of water and an oxidizing agent.

[0027] Preferably, steps S4 and S5 can be performed simultaneously.

[0028] (III) Beneficial Effects

[0029] This invention provides a method for manufacturing a brake disc metal disc body based on FNC processing. It has the following beneficial effects:

[0030] This method for manufacturing brake disc metal bodies based on FNC treatment involves adding an impregnation agent followed by high-temperature pressure application. A mixture of molten titanium oxide and iron oxide red is used as the pressure and heat transfer medium. The surface temperature is suddenly increased while applying pressure, which further enhances fatigue strength and wear resistance, improves product quality, and meets the user's needs. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the process of the present invention;

[0032] Figure 2 This is an image of the surface of the brake disc body of the present invention under an electron microscope;

[0033] Figure 3 The results are the performance test results of the disk obtained in Embodiments 1-3 of the present invention and the disk after traditional FNC operation after running for 7000km. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1-3 This invention provides a technical solution: a method for manufacturing a brake disc metal disc body based on FNC processing, the specific operation of which is as follows:

[0036] S1. Perform stress relief treatment on the brake disc body to eliminate the stress during the casting and machining process of the brake disc, and perform mechanical processing on the brake disc body according to production needs.

[0037] S2. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. At the same time, use nitrogen to balance the furnace pressure so that the furnace pressure is within a safe range.

[0038] S3. Perform pre-oxidation treatment on the brake disc body in the oxidation path. The temperature of the pre-oxidation treatment is 400-410℃ and the duration is 45-55min. A mixture of water and oxidant is used to oxidize the brake disc body.

[0039] S4. Perform nitriding and carbonization (FNC) treatment. Ensure the pressure inside the nitriding furnace is maintained between 18-22 kPa. The total amount of ammonia, carbon dioxide, and nitrogen depends on actual production needs. The volume ratio of ammonia, carbon dioxide, and nitrogen is 10:1:9. Specific procedures are as follows:

[0040] S41. Transfer the brake disc body to the nitriding furnace;

[0041] S42. Introduce carbon dioxide and nitrogen. During the introduction process, the temperature should be maintained between 550-560℃. After the gas pressure inside the nitriding furnace stabilizes, proceed to the next step.

[0042] S43. Introduce ammonia gas. After the introduction is complete, continue to maintain the ammonia gas for 1.5-4.5 hours before proceeding to the next step.

[0043] S5. Prepare the auxiliary agent. The raw materials for the auxiliary agent are titanium oxide powder and iron oxide red powder. The mass ratio of titanium oxide powder to iron oxide red powder is 1:3-1:4. Heat the auxiliary powder to 1600-1700℃ to make it melt and set aside.

[0044] S6. Remove the brake disc body from the nitriding furnace, and then immerse the brake disc body in the molten auxiliary agent obtained in step S5 for 1-3 minutes.

[0045] S7. Apply high-temperature pressure to the brake disc body. The pressure surface of the pressure mechanism is in contact with the surface of the brake disc body. Before applying pressure, the pressure surface needs to be heated to 1000-1100℃. The pressure intensity is 4-6 kPa. The pressure operation lasts for 5-10 minutes.

[0046] S8. Perform a cooling operation to reduce the surface temperature of the brake disc to 430-440℃ within 10 minutes.

[0047] S9. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. While evacuating the furnace, use nitrogen to balance the furnace pressure so that the pressure inside the furnace is within a safe range.

[0048] S10. Perform post-oxidation treatment on the brake disc body in the oxidation path. The temperature of the post-oxidation treatment is 400-410℃ and the duration is 45-55min. Use a mixture of water and oxidant to oxidize the brake disc body.

[0049] S11. Remove the brake disc body and perform subsequent additional processing operations on the brake disc body according to actual production needs.

[0050] It should be noted that steps S4 and S5 can be performed simultaneously.

[0051] Example 1

[0052] A method for manufacturing a brake disc metal disc body based on FNC processing, the specific operations are as follows:

[0053] S1. Perform stress relief treatment on the brake disc body to eliminate the stress during the casting and machining process of the brake disc, and perform mechanical processing on the brake disc body according to production needs.

[0054] S2. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. At the same time, use nitrogen to balance the furnace pressure so that the furnace pressure is within a safe range.

[0055] S3. Perform pre-oxidation treatment on the brake disc body in the oxidation path. The temperature of the pre-oxidation treatment is 400℃ and the duration is 49min. A mixture of water and oxidant is used to oxidize the brake disc body.

[0056] S4. Perform nitriding and carbonization (FNC) treatment. Ensure the pressure inside the nitriding furnace is maintained at 20 kPa. The total amount of ammonia, carbon dioxide, and nitrogen depends on actual production needs. The volume ratio of ammonia, carbon dioxide, and nitrogen is 10:1:9. Specific procedures are as follows:

[0057] S41. Transfer the brake disc body to the nitriding furnace;

[0058] S42. Introduce carbon dioxide and nitrogen. During the introduction process, the temperature must be maintained at 555℃. After the gas pressure inside the nitriding furnace stabilizes, proceed to the next step.

[0059] S43. Introduce ammonia gas. After the introduction is complete, continue to maintain the ammonia gas for 2 hours before proceeding to the next step.

[0060] S5. Prepare the auxiliary agent. The raw materials for the auxiliary agent are titanium oxide powder and iron oxide red powder. The mass ratio of titanium oxide powder to iron oxide red powder is 1:3. Heat the auxiliary powder to 1650℃ to make it melt and set aside.

[0061] S6. Remove the brake disc body relative to the nitriding furnace, and then immerse the brake disc body in the molten auxiliary agent obtained in step S5 for 1 minute.

[0062] S7. Apply high-temperature pressure to the brake disc body. The pressure surface of the pressure mechanism is in contact with the surface of the brake disc body. Before applying pressure, the pressure surface needs to be heated to 1000℃. The pressure intensity is 4kPa. The pressure operation lasts for 5 minutes.

[0063] S8. Perform a cooling operation to reduce the surface temperature of the brake disc body to 430°C within 10 minutes.

[0064] S9. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. While evacuating the furnace, use nitrogen to balance the furnace pressure so that the pressure inside the furnace is within a safe range.

[0065] S10. Perform post-oxidation treatment on the brake disc body in the oxidation path. The post-oxidation treatment temperature is 400℃ and the duration is 45min. Use a mixture of water and oxidant to oxidize the brake disc body.

[0066] It should be noted that steps S4 and S5 can be performed simultaneously.

[0067] Example 2

[0068] A method for manufacturing a brake disc metal disc body based on FNC processing, the specific operations are as follows:

[0069] S1. Perform stress relief treatment on the brake disc body to eliminate the stress during the casting and machining process of the brake disc, and perform mechanical processing on the brake disc body according to production needs.

[0070] S2. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. At the same time, use nitrogen to balance the furnace pressure so that the furnace pressure is within a safe range.

[0071] S3. Perform pre-oxidation treatment on the brake disc body in the oxidation path. The temperature of the pre-oxidation treatment is 410℃ and the duration is 55min. A mixture of water and oxidant is used to oxidize the brake disc body.

[0072] S4. Perform nitriding and carbonization (FNC) treatment. Ensure the pressure inside the nitriding furnace is maintained at 22 kPa. The total amount of ammonia, carbon dioxide, and nitrogen depends on actual production needs. The volume ratio of ammonia, carbon dioxide, and nitrogen is 10:1:9. Specific procedures are as follows:

[0073] S41. Transfer the brake disc body to the nitriding furnace;

[0074] S42. Introduce carbon dioxide and nitrogen. During the introduction process, the temperature must be maintained at 560℃. After the gas pressure inside the nitriding furnace stabilizes, proceed to the next step.

[0075] S43. Introduce ammonia gas. After the introduction is complete, continue to maintain this for 4.5 hours before proceeding to the next step.

[0076] S5. Prepare the auxiliary agent. The raw materials for the auxiliary agent are titanium oxide powder and iron oxide red powder. The mass ratio of titanium oxide powder to iron oxide red powder is 1:4. Heat the auxiliary powder to 1700℃ to make it melt and set aside.

[0077] S6. Remove the brake disc body relative to the nitriding furnace, and then immerse the brake disc body in the molten auxiliary agent obtained in step S5 for 3 minutes.

[0078] S7. Apply high-temperature pressure to the brake disc body. The pressure surface of the pressure mechanism is in contact with the surface of the brake disc body. Before applying pressure, the pressure surface needs to be heated to 1100℃. The pressure intensity is 5kPa. The pressure operation lasts for 10 minutes.

[0079] S8. Perform a cooling operation to reduce the surface temperature of the brake disc to 440°C within 10 minutes.

[0080] S9. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. While evacuating the furnace, use nitrogen to balance the furnace pressure so that the pressure inside the furnace is within a safe range.

[0081] S10. Perform post-oxidation treatment on the brake disc body in the oxidation path. The temperature of the post-oxidation treatment is 410℃ and the duration is 55min. The brake disc body is oxidized by a mixture of water and oxidant.

[0082] It should be noted that steps S4 and S5 can be performed simultaneously.

[0083] Example 3

[0084] A method for manufacturing a brake disc metal disc body based on FNC processing, the specific operations are as follows:

[0085] S1. Perform stress relief treatment on the brake disc body to eliminate the stress during the casting and machining process of the brake disc, and perform mechanical processing on the brake disc body according to production needs.

[0086] S2. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. At the same time, use nitrogen to balance the furnace pressure so that the furnace pressure is within a safe range.

[0087] S3. Perform pre-oxidation treatment on the brake disc body in the oxidation path. The temperature of the pre-oxidation treatment is 405℃ and the duration is 53min. A mixture of water and oxidant is used to oxidize the brake disc body.

[0088] S4. Perform nitriding and carbonization (FNC) treatment. Ensure the pressure inside the nitriding furnace is maintained at 21 kPa. The total amount of ammonia, carbon dioxide, and nitrogen depends on actual production needs. The volume ratio of ammonia, carbon dioxide, and nitrogen is 10:1:9. Specific procedures are as follows:

[0089] S41. Transfer the brake disc body to the nitriding furnace;

[0090] S42. Introduce carbon dioxide and nitrogen. During the introduction process, the temperature must be maintained at 555℃. After the gas pressure inside the nitriding furnace stabilizes, proceed to the next step.

[0091] S43. Introduce ammonia gas. After the introduction is complete, continue to maintain the ammonia gas for 3 hours before proceeding to the next step.

[0092] S5. Prepare the auxiliary agent. The raw materials for the auxiliary agent are titanium oxide powder and iron oxide red powder. The mass ratio of titanium oxide powder to iron oxide red powder is 2:7. Heat the auxiliary powder to 1650℃ to make it melt and set aside.

[0093] S6. Remove the brake disc body from the nitriding furnace, and then immerse the brake disc body in the molten auxiliary agent obtained in step S5 for 2 minutes.

[0094] S7. Apply high-temperature pressure to the brake disc body. The pressure surface of the pressure mechanism is in contact with the surface of the brake disc body. Before applying pressure, the pressure surface needs to be heated to 1050℃. The pressure intensity is 5kPa and the pressure operation lasts for 8 minutes.

[0095] S8. Perform a cooling operation to reduce the surface temperature of the brake disc body to 435°C within 10 minutes.

[0096] S9. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. While evacuating the furnace, use nitrogen to balance the furnace pressure so that the pressure inside the furnace is within a safe range.

[0097] S10. Perform post-oxidation treatment on the brake disc body in the oxidation path. The temperature of the post-oxidation treatment is 405℃ and the duration is 49min. The brake disc body is oxidized by a mixture of water and oxidant.

[0098] It should be noted that steps S4 and S5 can be performed simultaneously.

[0099] Depend on Figure 3 It can be seen that the products obtained in Examples 1-3 have stronger fatigue resistance and wear resistance than the products after traditional FNC operation. It should be noted that the data in the figure are the relative change data of the brake disc body, not the relative change data of the entire product. The disc body surface in Examples 1-3 will have some titanium oxide and iron oxide red residue, including the different layers of coatings that will be added to the disc body surface later. The thickness of this part is not included in the measurement. Only the disc body itself is included in the measurement.

[0100] In summary, this method for manufacturing brake disc metal bodies based on FNC treatment, by adding an impregnation aid followed by high-temperature pressure application, uses a mixture of molten titanium oxide and iron oxide red as the pressure and heat transfer medium, and suddenly increases the surface temperature while applying pressure, thereby further increasing fatigue strength and wear resistance, improving product quality and meeting user needs.

[0101] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0102] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a brake disc metal disc body based on FNC processing, characterized in that: The specific steps are as follows: S1. Perform stress relief treatment on the brake disc body to eliminate the stress during the brake disc casting and machining process, and perform mechanical machining operations on the brake disc body according to production needs. S2. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. At the same time, use nitrogen to balance the furnace pressure so that the furnace pressure is within a safe range. S3. Perform pre-oxidation treatment on the brake disc body in the oxidation furnace. S4. Perform nitriding and carbonitriding (FNC) treatment, as follows: S41. Transfer the brake disc body to the nitriding furnace; S42. Introduce carbon dioxide and nitrogen. During the introduction process, the temperature should be maintained between 550-560℃. After the gas pressure inside the nitriding furnace stabilizes, proceed to the next step. S43. Introduce ammonia gas. After the introduction is complete, continue to maintain the ammonia gas for 1.5-4.5 hours before proceeding to the next step. S5. Prepare the auxiliary agent. The raw materials for the auxiliary agent are titanium oxide powder and iron oxide red powder. The mass ratio of titanium oxide powder to iron oxide red powder is 1:3-1:

4. Heat the auxiliary powder to 1600-1700℃ to make it melt and set aside. S6. Remove the brake disc body from the nitriding furnace, and then immerse the brake disc body in the molten auxiliary agent obtained in step S5 for 1-3 minutes. S7. Apply high-temperature pressure to the brake disc body. The pressure surface of the pressure mechanism is in contact with the surface of the brake disc body. Before applying pressure, the pressure surface needs to be heated to 1000-1100℃. The pressure intensity is 4-6Mpa. The pressure operation lasts for 5-10 minutes. S8. Perform a cooling operation to reduce the surface temperature of the brake disc to 430-440℃ within 10 minutes. S9. Transfer the brake disc body to the oxidation furnace and evacuate the furnace pressure. While evacuating the furnace, use nitrogen to balance the furnace pressure so that the pressure inside the furnace is within a safe range. S10. Perform post-oxidation treatment on the brake disc body in the oxidation furnace. S11. Remove the brake disc body and perform subsequent additional processing operations on the brake disc body according to actual production needs.

2. The method for manufacturing a brake disc metal disc body based on FNC processing according to claim 1, characterized in that: In step S3, the pre-oxidation treatment temperature is 400-410℃ and the duration is 45-55min. A mixture of water and an oxidizing agent is used to oxidize the brake disc body.

3. The method for manufacturing a brake disc metal disc body based on FNC processing according to claim 1, characterized in that: In step S4, it is necessary to ensure that the pressure inside the nitriding furnace is maintained between 18-22 MPa.

4. The method for manufacturing a brake disc metal disc body based on FNC processing according to claim 1, characterized in that: In step S4, the total amount of ammonia, carbon dioxide, and nitrogen is determined according to actual production needs, and the volume ratio of ammonia, carbon dioxide, and nitrogen is 10:1:

9.

5. The method for manufacturing a brake disc metal disc body based on FNC processing according to claim 1, characterized in that: In step S10, the post-oxidation treatment temperature is 400-410℃ and the duration is 45-55min. A mixture of water and an oxidizing agent is used to oxidize the brake disc body.

6. The method for manufacturing a brake disc metal disc body based on FNC processing according to claim 1, characterized in that: Steps S4 and S5 can be performed simultaneously.

Images