Guide wheel forging process

Abstract

The invention discloses a guide wheel forging process, and particularly relates to the technical field of guide wheel machining, which comprises the following steps: blanking: cutting according to the required size and shape of a guide wheel to obtain a corresponding steel billet; pre-forging is conducted, specifically, the heated steel billet is put into an upsetting die in forging equipment to be subjected to upsetting forming; and forging, specifically, the upset steel billet is put into a rough forging die of forging equipment to be subjected to rough forging, a blank is obtained after rough forging is finished, chippings falling on the surface of the blank are removed, then the blank is put into a precision forging die, and a finished wheel body is obtained through precision forging. The guide wheel is machined in a forging mode, cracks are not prone to occurring in the heat treatment process, the internal structure and the element content of the forged guide wheel are uniform, the hardness can meet the requirement more easily, the stability of the forged guide wheel is better during heat treatment, the heating time is not longer than that of casting, and the service life of the forged guide wheel is prolonged. The cost is fundamentally reduced, so that the method plays a key role in improving the quality and reducing the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of guide wheel processing, and more particularly to a guide wheel forging process. Background Art

[0002] The guide wheel is an important part of the crawler-type engineering machinery's traveling mechanism. It is mainly used to guide the crawler to rotate correctly, prevent it from running off the track and derailing, and mitigate the impact of the crawler when it moves forward. The guide wheel bears heavy loads and slides on the surface of the crawler. Therefore, the wheel body of the guide wheel is required to have high strength and impact resistance, and its surface should also have high hardness and wear resistance.

[0003] The processing of the guide wheel is carried out by casting. The casting processing method is a relatively mature process, but it has obvious disadvantages, low efficiency, and obvious waste of materials. When the cast product is observed under a microscope, it is obvious that the grain size in the metallographic structure of the cast guide wheel is still abnormally coarse, and casting will cause element segregation inside the product, which may lead to cracks in the heat treatment process. Therefore, a guide wheel forging process is needed to solve the above problems. Summary of the invention

[0004] In order to overcome the above defects, the present invention provides a guide wheel forging process. The technical problem to be solved by the present invention is that casting the guide wheel will lead to element segregation inside, and the grain size in the metallographic structure is abnormally coarse, and cracks are prone to occur during the heat treatment process.

[0005] To achieve the above object, the present invention provides the following technical solution: a guide wheel forging process, comprising the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0006] As a further solution of the present invention: the steel billet is 35MnB or 40Mn2, and the debris on the surface of the steel billet is cleaned after the unloading is completed.

[0007] As a further solution of the present invention: in the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1180-1250°C, with a heating rate of 70-85°C / h, and the heating furnace is an electric heating furnace.

[0008] As a further solution of the present invention: the forging equipment is a 120MN free forging press, and the downward pressure of the forging press during the roughing forming process is controlled at 30-50mm. In the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated, and the preheating temperature is 150-400°C.

[0009] As a further solution of the present invention: after the finished wheel body is obtained by forging, the wheel body is cooled in a furnace in the forging equipment, and when the temperature drops to 400-550° C., it is taken out for heat treatment.

[0010] As a further solution of the present invention: in the high temperature normalizing in the heat treatment step, the forged wheel body is placed in a heating furnace, the wheel body is heated to 800-920°C, and normalized, the heating time is controlled to 3h, and then the temperature is reduced to 280-330°C, the cooling rate is controlled to 60-78°C / h, and the cooling method is furnace cooling; Tempering at room temperature, place the wheel body obtained after normalizing in a heating furnace, and heat the wheel body to 400-520℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 30-42℃ / h, take it out, and cool it naturally with air.

[0011] The beneficial effects of the present invention are: The present invention processes the guide wheel by forging. In the metallographic structure of the forged guide wheel, the grain size is regular and balanced, and cracks are not easy to appear during the heat treatment process. In addition, the internal structure and element content of the forged guide wheel are relatively uniform, and it is easier to make the hardness meet the requirements. The forged guide wheel has better stability during heat treatment, and the heating time is not as long as casting, which fundamentally reduces the cost, and thus plays a key role in improving quality and reducing costs. The present invention preheats the mold of the forging equipment during the forging process in advance to avoid direct contact between the heated steel billet and the mold with a large temperature difference, and to a certain extent avoids the situation where there is a large difference in the internal and external properties of the steel billet due to the large temperature difference. Preheating the mold can reduce the deformation resistance of the steel billet during forging, reduce the overall forging difficulty, and make the internal grains of the finished product after forging more uniform. After forging, high-temperature normalizing and room-temperature tempering are used for treatment. High-temperature normalizing refines the grains in the metallographic structure, and the high temperature can melt the internal inclusions. Room-temperature tempering can eliminate the stress generated during normalizing cooling, and improve the toughness and plasticity of the product. Implementation

[0012] 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. Example

[0013] A guide wheel forging process comprises the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0014] The steel billet is 35MnB. After unloading, the debris on the surface of the steel billet is cleaned.

[0015] In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1220°C at a heating rate of 80°C / h. The heating furnace is an electric heating furnace.

[0016] The forging equipment is a 120MN free forging press. During the roughing process, the downward pressure of the forging press is controlled at 48 mm. In the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 150°C.

[0017] After the finished wheel body is forged, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 500°C, it is taken out for heat treatment.

[0018] In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, heated to 900°C, and normalized. The heating time is controlled at 3h, and then the temperature is reduced to 300°C, the cooling rate is controlled at 75°C / h, and the cooling method is furnace cooling; Temper at room temperature, place the wheel body obtained after normalizing in a heating furnace, heat the wheel body to 500℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 40℃ / h, take it out and cool it naturally with air. Example

[0019] A guide wheel forging process comprises the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0020] The steel billet is 35MnB. After unloading, the debris on the surface of the steel billet is cleaned.

[0021] In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1220°C at a heating rate of 80°C / h. The heating furnace is an electric heating furnace.

[0022] The forging equipment is a 120MN free forging press. During the roughing process, the downward pressure of the forging press is controlled at 48 mm. During the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 200°C.

[0023] After the finished wheel body is forged, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 500°C, it is taken out for heat treatment.

[0024] In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, heated to 900°C, and normalized. The heating time is controlled at 3h, and then the temperature is reduced to 300°C, the cooling rate is controlled at 75°C / h, and the cooling method is furnace cooling; Temper at room temperature, place the wheel body obtained after normalizing in a heating furnace, heat the wheel body to 500℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 40℃ / h, take it out and cool it naturally with air. Example

[0025] A guide wheel forging process comprises the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0026] The steel billet is 35MnB. After unloading, the debris on the surface of the steel billet is cleaned.

[0027] In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1220°C at a heating rate of 80°C / h. The heating furnace is an electric heating furnace.

[0028] The forging equipment is a 120MN free forging press. During the roughing process, the downward pressure of the forging press is controlled at 48 mm. In the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 250°C.

[0029] After the finished wheel body is forged, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 500°C, it is taken out for heat treatment.

[0030] In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, heated to 900°C, and normalized. The heating time is controlled at 3h, and then the temperature is reduced to 300°C, the cooling rate is controlled at 75°C / h, and the cooling method is furnace cooling; Temper at room temperature, place the wheel body obtained after normalizing in a heating furnace, heat the wheel body to 500℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 40℃ / h, take it out and cool it naturally with air. Example

[0031] A guide wheel forging process comprises the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0032] The steel billet is 35MnB. After unloading, the debris on the surface of the steel billet is cleaned.

[0033] In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1220°C at a heating rate of 80°C / h. The heating furnace is an electric heating furnace.

[0034] The forging equipment is a 120MN free forging press. During the roughing process, the downward pressure of the forging press is controlled at 48 mm. In the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 300°C.

[0035] After the finished wheel body is forged, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 500°C, it is taken out for heat treatment.

[0036] In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, heated to 900°C, and normalized. The heating time is controlled at 3h, and then the temperature is reduced to 300°C, the cooling rate is controlled at 75°C / h, and the cooling method is furnace cooling; Temper at room temperature, place the wheel body obtained after normalizing in a heating furnace, heat the wheel body to 500℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 40℃ / h, take it out and cool it naturally with air. Example

[0037] A guide wheel forging process comprises the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0038] The steel billet is 35MnB. After unloading, the debris on the surface of the steel billet is cleaned.

[0039] In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1220°C at a heating rate of 80°C / h. The heating furnace is an electric heating furnace.

[0040] The forging equipment is a 120MN free forging press. During the roughing process, the downward pressure of the forging press is controlled at 48 mm. In the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 350°C.

[0041] After the finished wheel body is forged, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 500°C, it is taken out for heat treatment.

[0042] In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, heated to 900°C, and normalized. The heating time is controlled at 3h, and then the temperature is reduced to 300°C, the cooling rate is controlled at 75°C / h, and the cooling method is furnace cooling; Temper at room temperature, place the wheel body obtained after normalizing in a heating furnace, heat the wheel body to 500℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 40℃ / h, take it out and cool it naturally with air. Example

[0043] A guide wheel forging process comprises the following steps: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

[0044] The steel billet is 35MnB. After unloading, the debris on the surface of the steel billet is cleaned.

[0045] In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1220°C at a heating rate of 80°C / h. The heating furnace is an electric heating furnace.

[0046] The forging equipment is a 120MN free forging press. During the roughing process, the downward pressure of the forging press is controlled at 48 mm. During the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 400°C.

[0047] After the finished wheel body is forged, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 500°C, it is taken out for heat treatment.

[0048] In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, heated to 900°C, and normalized. The heating time is controlled at 3h, and then the temperature is reduced to 300°C, the cooling rate is controlled at 75°C / h, and the cooling method is furnace cooling; Temper at room temperature, place the wheel body obtained after normalizing in a heating furnace, heat the wheel body to 500℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 40℃ / h, take it out and cool it naturally with air.

[0049] The following table is obtained based on Examples 1-6: Mold preheating temperature (℃) Forming load (kN) Example 1 150 23800 Example 2 200 23500 Example 3 250 23300 Example 4 300 23000 Example 5 350 22300 Example 6 400 22000 From the comparison in the above table, we can see that: During the forging process, the mold of the forging equipment is preheated in advance to avoid direct contact between the heated billet and the mold with a large temperature difference. To a certain extent, this can avoid the situation where there is a large difference in the internal and external properties of the billet due to the large temperature difference. Preheating the mold will reduce the deformation resistance of the billet during forging, reduce the overall forging difficulty, and make the internal grains of the finished product after forging more uniform; and the higher the preheating temperature, the lower the forming load and the lower the pressure required for forging.

[0050] Finally, a few points should be explained: Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A guide wheel forging process, characterized in that: The following steps are involved: Cutting: Cutting the corresponding steel billet according to the required guide wheel size and shape; Pre-forging: putting the heated billet into the roughing die in the forging equipment for roughing forming; Forging, the roughened steel billet is placed in the rough forging die of the forging equipment for rough forging. After the rough forging is completed, the blank is obtained, the debris dropped on the surface is cleaned, and then it is placed in the fine forging die for fine forging to obtain the finished wheel body; Heat treatment, first high temperature normalizing, then room temperature tempering; Surface treatment: remove burrs on the surface of the cooled wheel body and apply protective agent; Ultrasonic flaw detection is used to detect flaws inside the wheel body and reject unqualified products.

2. A guide wheel forging process according to claim 1, characterized in that: The steel billet is 35MnB or 40Mn2, and the debris on the surface of the steel billet is cleaned after unloading.

3. A guide wheel forging process according to claim 1, characterized in that: In the heating operation in the pre-forging step, the steel billet obtained after cutting is placed in a heating furnace and heated to 1180-1250° C., with a heating rate of 70-85° C. / h. The heating furnace is an electric heating furnace.

4. A guide wheel forging process according to claim 1, characterized in that: The forging equipment is a 120MN free forging press. During the roughing forming process, the downward pressure of the forging press is controlled at 30-50 mm. During the pre-forging step and the forging step, the roughing die, the rough forging die and the fine forging die are all preheated at a temperature of 150-400°C.

5. The guide wheel forging process according to claim 1, characterized in that: After the finished wheel body is obtained by forging, the wheel body is cooled in a furnace in the forging equipment. When the temperature drops to 400-550° C., it is taken out for heat treatment.

6. A guide wheel forging process according to claim 1, characterized in that: In the high temperature normalizing of the heat treatment step, the forged wheel body is placed in a heating furnace, the wheel body is heated to 800-920°C, and normalized, the heating time is controlled at 3h, and then the temperature is reduced to 280-330°C, the cooling rate is controlled at 60-78°C / h, and the cooling method is furnace cooling; Tempering at room temperature, place the wheel body obtained after normalizing in a heating furnace, and heat the wheel body to 400-520℃, keep it warm for 2.5h, cool it down to 180℃ in the heating furnace, and the cooling rate is 30-42℃ / h, take it out, and cool it naturally with air.