A method of producing a special-shaped forging

Abstract

A production method of a special-shaped forging, comprising the following steps: S1, blanking, blanking according to a preset specification to form a blank; S2, forging; S3, die forging, the die of the die forging comprises a bottom die, a middle die and a top die, a lower die core is arranged in the die cavity of the bottom die, the minimum diameter section of the workpiece is matched with the die cavity of the bottom die, the lower die core is located in the center hole of the workpiece, and the height of the lower die core is greater than the height of the minimum center hole of the workpiece; S4, heat treatment after forging, adopting normal tempering quenching and tempering heat treatment; and S5, ultrasonic flaw detection.

Description

Technical Field

[0001] This application relates to the field of forging technology, and more specifically, to a method for preparing a special-shaped forging. Background Technology

[0002] Large wind power equipment also contains many irregularly shaped components, such as... Figure 1 As shown, during processing, in addition to forging and rolling rings in the conventional way of flanges, bearings, etc., its irregular structure mainly relies on subsequent machining to complete the processing. When machining, firstly, the workpiece is large in size, and the clamping and unloading of the workpiece during the machining process is very troublesome, and the machining efficiency is low. Although the accuracy can be guaranteed, a lot of raw materials will be wasted. Therefore, the traditional processing method is time-consuming and costly. Summary of the Invention

[0003] The main objective of this application is to provide a method for producing irregularly shaped forgings that eliminates the need for machining, greatly reduces processing steps, saves raw materials, and lowers costs.

[0004] To achieve the above objectives, firstly, this application provides a method for producing irregularly shaped forgings, comprising the following steps: S1. Cutting: Cutting materials according to preset specifications to form blanks; S2. Forging: Select a hydraulic press and a ring rolling mill to perform two upsetting and one drawing process on the billet. Then, use a ring rolling mill for ring rolling. The forging temperature is 800-1250℃, and the forging is controlled to be done in three stages. The forging ratio is ≥6. The inner diameter after ring rolling is the same as the minimum inner diameter designed for the workpiece, the outer diameter after ring rolling is the same as the minimum outer diameter designed for the workpiece, and the height after ring rolling is greater than the height designed for the workpiece. S3. Die forging: The die forging mold includes a bottom die, a middle die, and a top die. The bottom die cavity is provided with a lower die core. The minimum diameter section of the workpiece is matched with the bottom die cavity. The lower die core is located in the center hole of the workpiece. The height of the lower die core is greater than the height of the minimum center hole of the workpiece. The middle die is matched with the tapered neck of the workpiece. The top die cavity is fixedly provided with an upper die core. The maximum diameter section of the workpiece is matched with the top die cavity. The upper die core includes a straight section and an inclined section. The straight section is matched with the center hole of the maximum inner diameter of the workpiece. The inclined section is matched with the center hole of the neck of the workpiece. The upper die core is also provided with a positioning groove. The top of the lower die core is matched with the positioning groove. The bottom of the workpiece is placed into the bottom die cavity. The middle die and the top die are installed in sequence. The top die is reciprocated linearly by a hydraulic press to perform die forging until it is the same as the design size of the workpiece. S4. Post-forging heat treatment: normalizing, tempering and quenching heat treatment. S5. Ultrasonic flaw detection.

[0005] A further improvement is that multiple padding layers are provided between the middle mold and the top mold, and the multiple padding layers are detachably connected to each other, to the middle mold, and to the top mold.

[0006] A further improvement is to gradually reduce the number of pads until the middle die and the top die are adjacent before the final forging is performed.

[0007] A further improvement is that the hydraulic press is a 5000T hydraulic press, and the ring rolling machine is a 6.5-meter horizontal ring rolling machine.

[0008] A further improvement is that in step S4, the temperature is held at 860℃ for ≥1h, then furnace cooled to 650℃ and held for ≥1h, followed by air cooling. The heat treatment is then adjusted to a quenching temperature ≤860±10℃ and a tempering temperature ≥480℃.

[0009] The present invention provides a method for producing irregular forgings. Compared with the prior art, its advantages are that the blanks formed after die forging and rolling are directly die forged. By designing the die forging mold, the machining of the workpiece after forming is avoided, which not only improves production efficiency but also greatly reduces costs. Attached Figure Description

[0010] Figure 1 A schematic diagram of the workpiece; Figure 2 Flowchart of workpiece processing. Detailed Implementation

[0011] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0012] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0013] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0014] In addition, the term "multiple" should mean two or more.

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the embodiments.

[0016] A method for producing irregularly shaped forgings includes the following steps: S1. Cutting: Cutting materials according to preset specifications to form blanks; S2. Forging: A hydraulic press and ring rolling mill are used to process the billet through two upsetting and one drawing. The ring rolling process is then performed. The forging temperature is 800-1250℃, and three-stage forging is controlled. The forging ratio is ≥6. The inner diameter and outer diameter after ring rolling are the same as the minimum designed inner diameter of workpiece 8. The height after ring rolling is greater than the designed height of workpiece 8. A schematic diagram of workpiece 8 is shown below. Figure 1 As shown; S3, die forging, such as Figure 2As shown, the forging die includes a bottom die 1, a middle die 2, and a top die 3. A lower die core 4 is disposed within the cavity of the bottom die 1. The minimum diameter section of the workpiece 8 mates with the cavity of the bottom die 1. The lower die core 4 is located within the center hole of the workpiece 8, and its height is greater than the height of the minimum center hole of the workpiece 8. The middle die 2 mates with the tapered neck of the workpiece 8. An upper die core 5 is fixedly disposed within the cavity of the top die 3. The maximum diameter section of the workpiece 8 mates with the cavity of the top die 3. The upper die core 5 includes a straight section and an inclined section. The straight section mates with the center hole of the maximum inner diameter of the workpiece 8, and the inclined section mates with the center hole of the neck of the workpiece 8. The upper die core 5 also has a positioning groove 6. The top of the lower die core 4 mates with the positioning groove 6. The bottom of the workpiece 8 is placed into the cavity of the bottom die 1, and the workpieces are installed sequentially. The middle die 2 and the top die 3 are forged by reciprocating linear motion of the top die controlled by a hydraulic press until the design dimensions of the workpiece 8 are the same. In addition, in order to ensure the strength and dimensional accuracy of the workpiece 8 after forming, multiple pads 7 are provided between the middle die 2 and the top die 3. The multiple pads 7 are detached and connected to each other, to the middle die 2, and to the top die 3, and the number of pads 7 is gradually reduced until the middle die 2 and the top die 3 are adjacent and the final forging is performed. That is, when forging, for example, if three pads 7 are set, the first forging is performed with three pads 7, then one pad 7 is removed and the forging is performed again, and so on, until the middle die 2 and the top die 3 are in contact, that is, there are no pads 7 left, and the final forging is performed. This ensures the dimensional accuracy of forging and ensures that the die is not easily damaged by excessive force during the forging process. S4. Post-forging heat treatment: normalizing, tempering and quenching heat treatment. S5. Ultrasonic flaw detection.

[0017] More preferably, the hydraulic press is a 5000T hydraulic press, and the ring rolling machine is a 6.5-meter horizontal ring rolling machine.

[0018] In this embodiment, preferably, in step S4, the temperature is held at 860℃ for ≥1h, then furnace cooled to 650℃ and held for ≥1h, followed by air cooling. The heat treatment is adjusted to a quenching temperature ≤860±10℃ and a tempering temperature ≥480℃.

[0019] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of producing a special-shaped forging, characterized by, Includes the following steps: S1. Cutting: Cutting materials according to preset specifications to form blanks; S2. Forging: Select a hydraulic press and a ring rolling mill to perform two upsetting and one drawing process on the billet. Then, use a ring rolling mill for ring rolling. The forging temperature is 800-1250℃, and the forging is controlled to be done in three stages. The forging ratio is ≥6. The inner diameter after ring rolling is the same as the minimum inner diameter designed for the workpiece, the outer diameter after ring rolling is the same as the minimum outer diameter designed for the workpiece, and the height after ring rolling is greater than the height designed for the workpiece. S3. Die forging: The die forging mold includes a bottom die, a middle die, and a top die. The bottom die cavity is provided with a lower die core. The minimum diameter section of the workpiece is matched with the bottom die cavity. The lower die core is located in the center hole of the workpiece. The height of the lower die core is greater than the height of the minimum center hole of the workpiece. The middle die is matched with the tapered neck of the workpiece. The top die cavity is fixedly provided with an upper die core. The maximum diameter section of the workpiece is matched with the top die cavity. The upper die core includes a straight section and an inclined section. The straight section is matched with the center hole of the maximum inner diameter of the workpiece. The inclined section is matched with the center hole of the neck of the workpiece. The upper die core is also provided with a positioning groove. The top of the lower die core is matched with the positioning groove. The bottom of the workpiece is placed into the bottom die cavity. The middle die and the top die are installed in sequence. The top die is reciprocated linearly by a hydraulic press to perform die forging until it is the same as the design size of the workpiece. S4. Post-forging heat treatment: normalizing, tempering and quenching heat treatment. S5. Ultrasonic flaw detection.

2. The method for producing a special-shaped forging as described in claim 1, characterized in that: Multiple pads are provided between the middle mold and the top mold, and the multiple pads are detachably connected to each other, to the middle mold, and to the top mold.

3. The method for producing a special-shaped forging as described in claim 2, characterized in that: During the die forging process, the number of backing layers is gradually reduced until the middle die and the top die are adjacent, at which point the final die forging is performed.

4. The method for producing a special-shaped forging as described in claim 1, characterized in that: The hydraulic press is a 5000T hydraulic press, and the ring rolling machine is a 6.5-meter horizontal ring rolling machine.

5. A method of producing a profiled forging according to claim 1, characterized in that: In step S4, the temperature is held at 860℃ for ≥1 hour, then furnace cooled to 650℃ and held for ≥1 hour, followed by air cooling. The heat treatment is then adjusted to a quenching temperature ≤860±10℃ and a tempering temperature ≥480℃.

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