Nickel-based alloy bar forge piece and forging method thereof

Abstract

The invention provides a nickel-based alloy bar forge piece and a forging method thereof, and relates to the technical field of forging, the forging method comprises the following steps: S1, carrying out homogenization heat treatment and multiple upsetting and drawing on a nickel-based alloy cast ingot to obtain a first intermediate blank; s2, the first intermediate blank is heated to the drawing-out temperature, final heating number drawing-out treatment is conducted, and a second intermediate blank is obtained; s3, the second intermediate blank is heated to the extrusion temperature, extrusion treatment is conducted, and a nickel-based alloy bar forge piece is obtained; wherein the extrusion temperature ranges from 980 DEG C to 1060 DEG C, and the extrusion ratio of the extrusion treatment ranges from 1.2 to 2. By the adoption of the method, the recrystallization proportion of the surface structure of the nickel-based alloy bar forging can be increased, and grain coarsening in the recrystallization process can be prevented.

Description

Technical Field

[0001] The invention relates to the technical field of forging, and in particular to a nickel-based alloy bar forging and a forging method thereof. Background Art

[0002] The forging process of nickel-based alloy bars is generally multiple upsetting and drawing. In the final forming fire, in order to control the final grain size of the forging, the heating temperature is generally reduced. In addition, in order to ensure the dimensional accuracy of the forging, the jacketing and other measures cannot be used in the final forming fire. These two factors cause the surface temperature of the billet to drop rapidly during the furnace transfer and forging process, the deformation resistance increases, and the surface deformation is very small, making it difficult to recrystallize the surface structure of the forging, forming mixed crystals or no recrystallization at all. Subsequent rough processing requires the mixed crystals or coarse crystals on the surface of the forging to be completely turned off, reducing the utilization rate of the nickel-based alloy material. Summary of the invention

[0003] The problem solved by the invention is: how to improve the recrystallization ratio of the surface structure of the nickel-based alloy bar forging and prevent the coarsening of the grains during the recrystallization process.

[0004] In order to solve the above problems, the present invention provides a forging method of a nickel-based alloy bar forging, comprising:

[0005] Step S1, subjecting the nickel-based alloy ingot to homogenization heat treatment and multiple upsetting and drawing to obtain a first intermediate billet;

[0006] Step S2, heating the first intermediate blank to a drawing temperature, performing a final drawing treatment, and obtaining a second intermediate blank;

[0007] Step S3, heating the second intermediate billet to an extrusion temperature, performing an extrusion process, and obtaining a nickel-based alloy bar forging; wherein the extrusion temperature is 980-1060°C, and the extrusion ratio of the extrusion process is 1.2-2.

[0008] Optionally, in step S3, the die angle of the extrusion die used in the extrusion process is 65-80 degrees.

[0009] Optionally, in step S1, the multiple upsetting and drawing include two upsetting and one drawing or three upsetting and two drawing.

[0010] Optionally, in step S1, the initial forging temperature during the multiple upsetting and drawing processes is 1100-1200°C.

[0011] Optionally, in step S1, during the multiple upsetting processes, the deformation amount of each upsetting process is 40-60%.

[0012] Optionally, in step S1, the temperature of the homogenization heat treatment is 1160-1200° C., and the time is 92-100 h.

[0013] Optionally, in step S2, the drawing temperature is 1020-1100°C.

[0014] Optionally, in step S2, during the final-fire lengthening process, the deformation amount in a single fire is 30-60%.

[0015] Optionally, in step S1, the preparation material of the nickel-based alloy ingot includes one of GH4169 alloy and IN617 alloy.

[0016] The present invention also provides a nickel-based alloy bar forging, which is made by the forging method of the nickel-based alloy bar forging as described above.

[0017] Compared with the prior art, the present invention further performs an extrusion process on the billet after the final fire drawing process. By reasonably controlling the extrusion temperature and the extrusion ratio, the recrystallization ratio of the surface structure of the nickel-based alloy bar forging can be increased, and the coarsening of the grains during the recrystallization of the surface structure can be prevented. Specifically, by adopting a relatively low extrusion temperature (980-1060°C) and a relatively low extrusion ratio (1.2-2), the deformation of the billet during the extrusion process is mainly concentrated on the surface layer, ensuring that the surface layer of the billet produces sufficient deformation, thereby increasing the recrystallization ratio of the surface structure of the forging, preventing the occurrence of mixed crystals in the surface structure or no recrystallization at all, thereby improving the utilization rate of the nickel-based alloy material. In addition, by adopting a relatively low extrusion temperature (980-1060°C) and a relatively low extrusion ratio (1.2-2), the present invention can prevent the coarsening of the grains in the surface structure during the recrystallization process due to excessively high extrusion temperature or excessively large extrusion ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a process for forging a nickel-based alloy bar forging;

[0019] Figure 2 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Example 1;

[0020] Figure 3 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Comparative Example 1;

[0021] Figure 4 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Example 2;

[0022] Figure 5 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Comparative Example 2;

[0023] Figure 6 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Example 3;

[0024] Figure 7 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Comparative Example 3;

[0025] Figure 8 This is a metallographic structure picture of the surface of the nickel-based alloy bar forging prepared in Comparative Example 4. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0028] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0029] It should be noted that the die angle of the extrusion die in the present invention refers to the angle formed between the axis of the extrusion die and its working end surface.

[0030] In view of the problems existing in the above-mentioned related technologies, such as Figure 1 As shown, this embodiment provides a forging method for a nickel-based alloy bar forging, comprising:

[0031] Step S1, subjecting the nickel-based alloy ingot to homogenization heat treatment and multiple upsetting and drawing to obtain a first intermediate billet;

[0032] Step S2, heating the first intermediate blank to a drawing temperature, performing a final drawing treatment, and obtaining a second intermediate blank;

[0033] Step S3, heating the second intermediate billet to an extrusion temperature, performing an extrusion process, and obtaining a nickel-based alloy bar forging; wherein the extrusion temperature is 980-1060°C, and the extrusion ratio of the extrusion process is 1.2-2.

[0034] After the final fire and drawing treatment of the billet, the embodiment of the present invention further performs an extrusion treatment on the billet. By reasonably controlling the extrusion temperature and the extrusion ratio, the recrystallization ratio of the surface structure of the nickel-based alloy bar forging can be increased, and the coarsening of the grains during the recrystallization of the surface structure can be prevented. Specifically, by adopting a relatively low extrusion temperature (980-1060°C) and a relatively low extrusion ratio (1.2-2), the deformation of the billet during the extrusion process is mainly concentrated on the surface layer, ensuring that the surface layer of the billet produces sufficient deformation, thereby increasing the recrystallization ratio of the surface structure of the forging, preventing the occurrence of mixed crystals or no recrystallization in the surface structure, thereby improving the utilization rate of the nickel-based alloy material. In addition, by adopting a relatively low extrusion temperature (980-1060°C) and a relatively low extrusion ratio (1.2-2), the embodiment of the present invention can prevent the coarsening of the grains in the surface structure during the recrystallization process due to excessively high extrusion temperature or excessively large extrusion ratio.

[0035] In some embodiments of the present invention, in step S3, the die angle of the extrusion die used in the extrusion process is 65-80 degrees. Generally speaking, the die angle of the extrusion die used in the extrusion process is 45-60 degrees. The die angle of the extrusion die used in this embodiment is larger, which can reduce the extrusion pressure surplus, thereby further improving the utilization rate of the material.

[0036] In some embodiments of the present invention, in step S1, the multiple upsetting and drawing include two upsetting and one drawing or three upsetting and two drawing. Two upsetting and one drawing means upsetting, drawing, and upsetting are performed on the blank in sequence; three upsetting and two drawing means upsetting, drawing, upsetting, drawing, and upsetting are performed on the blank in sequence.

[0037] In some embodiments of the present invention, in step S1, the initial forging temperature during the multiple upsetting and drawing process is 1100-1200°C; during the multiple upsetting and drawing process, the deformation amount of each fire is 40-60%. In this embodiment, a higher initial forging temperature is used and the deformation amount is as large as possible, so that the blank can be forged through, thereby improving the uniformity of the forging structure. However, when the upsetting deformation exceeds 60%, cracking is likely to occur, and instability occurs during the subsequent drawing.

[0038] In some embodiments of the present invention, in step S1, the temperature of the homogenization heat treatment is 1160-1200° C. and the time is 92-100 h.

[0039] In some embodiments of the present invention, in step S2, the drawing temperature is 1020-1100°C; during the final drawing treatment, the deformation amount of each fire is 30-60%. In this embodiment, the grain size of the core of the forging is ensured to be as small as possible by controlling the drawing temperature and the deformation amount of each fire.

[0040] In some embodiments of the present invention, in step S1, the preparation material of the nickel-based alloy ingot includes one of GH4169 alloy and IN617 alloy.

[0041] The present invention also provides a nickel-based alloy bar forging, which is made by the forging method of the nickel-based alloy bar forging as described above.

[0042] The present invention is further described below in conjunction with specific embodiments.

[0043] Example 1

[0044] A1. Subjecting the nickel-based alloy ingot to homogenization heat treatment and two upsetting and one drawing (i.e., upsetting, drawing, upsetting) to obtain a first intermediate billet; wherein the nickel-based alloy ingot is made of GH4169 alloy, is cylindrical in shape, has a diameter of 400 mm, and a height of 1000 mm, and the homogenization heat treatment comprises: heating the nickel-based alloy ingot to 1160° C., keeping it warm for 24 hours, and then heating it to 1200° C., keeping it warm for 72 hours; the initial forging temperature in the two upsetting and one drawing process is 1100° C., and the deformation amount per fire is 40%.

[0045] A2. The first intermediate blank is heated to a drawing temperature and subjected to a final drawing treatment to obtain a second intermediate blank; wherein the drawing temperature is 1020° C., and during the final drawing treatment, the deformation amount of a single drawing is 30%.

[0046] A3. Heat the second intermediate billet to the extrusion temperature and perform extrusion treatment to obtain a nickel-based alloy bar forging; wherein the extrusion temperature is 980° C., the extrusion ratio of the extrusion treatment is 1.2; and the die angle of the extrusion die used in the extrusion treatment is 65 degrees.

[0047] Example 2

[0048] A1. Subjecting the nickel-based alloy ingot to homogenization heat treatment and two upsets and one drawing (i.e., upsetting, drawing, upsetting) to obtain a first intermediate billet; wherein the nickel-based alloy ingot is made of GH4169 alloy, is cylindrical in shape, has a diameter of 600 mm, and a height of 1800 mm, and the homogenization heat treatment comprises: heating the nickel-based alloy ingot to 1160° C., keeping it warm for 24 hours, and then heating it to 1200° C., keeping it warm for 72 hours; the initial forging temperature in the two upsets and one drawing process is 1120° C., and the deformation amount per fire is 50%.

[0049] A2. The first intermediate blank is heated to a drawing temperature and subjected to a final drawing treatment to obtain a second intermediate blank; wherein the drawing temperature is 1040° C., and during the final drawing treatment, the deformation amount in a single drawing is 50%.

[0050] A3. Heat the second intermediate billet to the extrusion temperature and perform extrusion treatment to obtain a nickel-based alloy bar forging; wherein the extrusion temperature is 1020° C., the extrusion ratio of the extrusion treatment is 1.5; and the die angle of the extrusion die used in the extrusion treatment is 70 degrees.

[0051] Example 3

[0052] A1. Subjecting a nickel-based alloy ingot to homogenization heat treatment and three upsetting and two drawing processes (i.e., upsetting, drawing, upsetting, drawing, upsetting) to obtain a first intermediate billet; wherein the nickel-based alloy ingot is made of IN617 alloy, is cylindrical in shape, has a diameter of 900 mm, and a height of 1800 mm, and the homogenization heat treatment comprises: heating the nickel-based alloy ingot to 1200° C. and keeping it warm for 96 hours; the initial forging temperature in the three upsetting and two drawing process is 1200° C., and the deformation amount per fire is 60%.

[0053] A2. The first intermediate blank is heated to a drawing temperature and subjected to a final drawing treatment to obtain a second intermediate blank; wherein the drawing temperature is 1100° C., and during the final drawing treatment, the deformation amount of a single drawing is 60%.

[0054] A3. Heat the second intermediate billet to the extrusion temperature and perform extrusion treatment to obtain a nickel-based alloy bar forging; wherein the extrusion temperature is 1060° C., the extrusion ratio of the extrusion treatment is 2; and the die angle of the extrusion die used in the extrusion treatment is 80 degrees.

[0055] Comparative Example 1

[0056] A1. Subjecting the nickel-based alloy ingot to homogenization heat treatment and two upsetting and one drawing (i.e., upsetting, drawing, upsetting) to obtain a first intermediate billet; wherein the nickel-based alloy ingot is made of GH4169 alloy, is cylindrical in shape, has a diameter of 400 mm, and a height of 1000 mm, and the homogenization heat treatment comprises: heating the nickel-based alloy ingot to 1160° C., keeping it warm for 24 hours, and then heating it to 1200° C., keeping it warm for 72 hours; the initial forging temperature in the two upsetting and one drawing process is 1100° C., and the deformation amount per fire is 40%.

[0057] A2. The first intermediate billet is heated to a drawing temperature and subjected to a final drawing treatment to obtain a nickel-based alloy bar forging; wherein the drawing temperature is 1020° C., and during the final drawing treatment, the deformation amount of a single drawing is 30%.

[0058] Comparative Example 2

[0059] The difference from Example 2 is that in step A3, the extrusion ratio of the extrusion treatment is 3.

[0060] Comparative Example 3

[0061] The difference from Example 3 is that in step A3, the extrusion temperature is 950°C.

[0062] Comparative Example 4

[0063] The difference from Example 3 is that in step A3, the extrusion temperature is 1100°C.

[0064] Experimental example

[0065] The surface metallographic structures of the nickel-based alloy bar forgings prepared in Examples 1-3 and Comparative Examples 1-4 were characterized. Figure 2-8 It should be noted that Figure 2-3 The length represented by the middle ruler is 100 microns. Figure 4-8 The length represented by the middle scale bar is 5 microns.

[0066] from Figure 2 and Figure 3 It can be seen that the surface structure of the nickel-based alloy bar forging obtained in Example 1 has been completely recrystallized, and the average grain size is small (32 microns) and the grain size is uniform; the surface structure of the nickel-based alloy bar forging obtained in Comparative Example 1 is not completely recrystallized and there is a mixed crystal phenomenon. Figure 4 and Figure 5 It can be seen that the surface structure of the nickel-based alloy bar forging obtained in Example 2 has been completely recrystallized, and the average grain size is small (51 microns) and the grain size is uniform; although the surface structure of the nickel-based alloy bar forging obtained in Comparative Example 2 has been completely recrystallized, the average grain size is large (82 microns). Figure 6-8It can be seen that the surface structure of the nickel-based alloy bar forging prepared in Example 3 is completely recrystallized, and the average grain size is small (37 microns) and the grain size is uniform; the surface structure of the nickel-based alloy bar forging prepared in Comparative Example 3 is incompletely recrystallized, and there is a mixed crystal phenomenon; although the surface structure of the nickel-based alloy bar forging prepared in Comparative Example 4 is completely recrystallized, the average grain size is large (79 microns).

[0067] In summary, the surface structure of the nickel-based alloy bar forgings produced by the forging method according to the embodiment of the present invention is completely recrystallized, and the grains are fine and uniform in size.

[0068] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A forging method for a nickel-based alloy bar forging, characterized in that: include: Step S1, subjecting the nickel-based alloy ingot to homogenization heat treatment and multiple upsetting and drawing to obtain a first intermediate billet; Step S2, heating the first intermediate blank to a drawing temperature, performing a final drawing treatment, and obtaining a second intermediate blank; Step S3, heating the second intermediate billet to an extrusion temperature, performing an extrusion process, and obtaining a nickel-based alloy bar forging; wherein the extrusion temperature is 980-1060°C, and the extrusion ratio of the extrusion process is 1.2-2.

2. The forging method of the nickel-based alloy bar forging according to claim 1, characterized in that: In the step S3, the die angle of the extrusion die used in the extrusion process is 65-80 degrees.

3. The forging method of the nickel-based alloy bar forging according to claim 1, characterized in that: In the step S1, the multiple upsetting and drawing include two upsetting and one drawing or three upsetting and two drawing.

4. The forging method of the nickel-based alloy bar forging according to claim 1, characterized in that: In the step S1, the initial forging temperature during the multiple upsetting and drawing processes is 1100-1200°C.

5. The forging method of nickel-based alloy bar forging according to claim 1, characterized in that: In the step S1, during the multiple upsetting processes, the deformation amount of each upsetting process is 40-60%.

6. The forging method of the nickel-based alloy bar forging according to claim 1, characterized in that: In the step S1, the temperature of the homogenization heat treatment is 1160-1200° C. and the time is 92-100 hours.

7. The forging method of the nickel-based alloy bar forging according to claim 1, characterized in that: In the step S2, the drawing temperature is 1020-1100°C.

8. The forging method of nickel-based alloy bar forging according to claim 1, characterized in that: In the step S2, during the final-fire stretching process, the deformation amount in a single fire is 30-60%.

9. The forging method of nickel-based alloy bar forging according to claim 1, characterized in that: In the step S1, the preparation material of the nickel-based alloy ingot includes one of GH4169 alloy and IN617 alloy.

10. A nickel-based alloy bar forging, characterized in that: The nickel-based alloy bar forging is made by the forging method of any one of claims 1 to 9.

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