CN112893725A

CN112893725A - Method for improving surface quality of titanium alloy forging

Info

Publication number: CN112893725A
Application number: CN202011588955.5A
Authority: CN
Inventors: 姜欢; 刘兴华; 毕争辉; 任意; 李名言
Original assignee: China Steel Precision Materials Co ltd
Current assignee: China Steel Precision Materials Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-06-04

Abstract

The invention discloses a method for improving the surface quality of a titanium alloy forging, which utilizes forging pressing amount control to improve the finish forging temperature and change the traditional square forging into polygonal forging so as to effectively reduce or eliminate the defects of bark grains, cracking and the like on the surface of the titanium alloy forging. The surface quality of the titanium alloy forging is improved, the manufacturability and the yield are improved, the production cost is reduced, and the requirements of industrial mass production are met.

Description

Method for improving surface quality of titanium alloy forging

Technical Field

The invention belongs to the technical field of titanium alloy casting processes, and particularly relates to a method for improving the surface quality of a titanium alloy forging.

Background

The metal titanium is a metal material with excellent performance, has the characteristics of high specific strength, good corrosion resistance, no magnetism and excellent comprehensive performance, and is widely applied to the fields of aviation, aerospace, navigation, chemical industry, sports and the like.

TA18(Ti-3Al-2.5V) is a low alloyed near alpha titanium alloy with better cold formability and weldability, room temperature strength 20% -50% higher than industrial pure titanium, and good corrosion resistance in many media. Therefore, the TA18 alloy is the most ideal material for manufacturing the high-pressure-resistant light-weight conduit on the airplane due to the excellent combination property. TA10(Ti-0.3Mo-0.8Ni) is a titanium alloy with added Mo and Ni elements to improve the anti-gap corrosion ability, and is widely applied to chemical industry and salt industry, and is a higher-end product than pure titanium.

At present, in the conventional titanium alloy production forging process, because a titanium alloy ingot needs to be heated for a certain time at high temperature before forging, a special corrosion-resistant oxide layer is generated on the surface to improve the corrosion resistance, but bark-shaped wrinkles and even cracking on the surface can be generated when a blank is forged from the ingot.

Disclosure of Invention

In order to solve the existing problems, the invention provides a method for improving the surface quality of a titanium alloy forging, which improves the manufacturability and the yield and reduces the production cost.

The technical scheme adopted by the invention is as follows:

a method for improving the surface quality of a titanium alloy forging piece utilizes forging pressing amount control to improve the finish forging temperature and change the traditional square forging into polygonal forging so as to effectively reduce or eliminate defects of bark grains, cracking and the like on the surface of the titanium alloy forging piece.

The polygon is forged with n sides (n is 6,8,12 …).

Preferably, the titanium alloy may be TA18(GR9), TC4(GR5) or TA10(GR 12).

On the basis of the technical scheme, the pressing amount is preferably less than or equal to 70mm, and more preferably 50-60 mm.

The finish forging temperature is more than or equal to 780 ℃, preferably more than or equal to 800 ℃.

The weight of the forging blank is 1-5 tons, and the diameter of the ingot is 300-1000 mm.

The temperature of the forging furnace is 1000-1150 ℃, preferably more than or equal to 1100 ℃.

Furthermore, the smelting mode is vacuum consumable electrode arc smelting, electroslag smelting, vacuum skull furnace smelting, vacuum non-consumable arc smelting, electron beam smelting and plasma beam (or plasma arc) smelting.

The square billet produced by the method can be used for producing bars, flat materials, wires, coils, pierced billets, extruded tubes, plates, forged materials and the like in series.

Compared with the prior art, the invention has the beneficial effects that:

the invention reduces the pressing amount, controls the finish forging temperature and changes the traditional square forging into polygonal forging so as to effectively reduce or eliminate the defects of surface wrinkles, cracking and the like of the titanium alloy forging. By improving the surface quality of the titanium alloy forging, the manufacturability and the yield are improved, the production cost is reduced, and the requirements of industrial batch production are met.

Drawings

Fig. 1 is a process diagram of square forging of a titanium alloy and a surface diagram of a forged product in comparative example 1.

Fig. 2 is a process diagram of octagonal forging of a titanium alloy of comparative example 2 and a surface diagram of a forged product.

FIG. 3 is a process diagram of titanium alloy forging and a surface diagram of a forged product according to embodiment 1 of the present invention.

FIG. 4 is a process diagram of titanium alloy forging and a surface diagram of a forged product according to embodiment 2 of the invention.

FIG. 5 is a process diagram of titanium alloy forging and a surface diagram of a forged product according to embodiment 3 of the invention.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the purpose of facilitating understanding of the present invention and should not be construed as specifically limiting the present invention.

Unless otherwise specified, various starting materials of the present invention are commercially available; or prepared according to conventional methods in the art. Unless defined or indicated otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention.

Comparative example 1

Taking GR9 forging as an example, using traditional square forging to forge a phi 600mm ingot to a 300mm square billet, controlling the finish forging temperature and the pressing amount, wherein the forging parameters are shown in Table 1, and as shown in FIG. 1, the surface wrinkle defect of the forged product is serious.

Comparative example 2

Taking GR9 forging as an example, a phi 600mm ingot is forged to a 300mm square billet by utilizing eight-direction forging, the finish forging temperature is controlled, the forging parameters are shown in Table 1, and as shown in FIG. 2, the surface wrinkle defect of the forged product is serious.

Example 1(GR9 forging)

And (3) forging the phi 600mm ingot to a 300mm square billet by utilizing hexagonal forging, controlling the finish forging temperature and the pressing amount, wherein the forging parameters are shown in table 1, and as shown in figure 3, the surface wrinkles of the forged product are basically eliminated.

Example 2(GR9 forging)

And (3) forging the phi 600mm ingot to a 300mm square billet by utilizing eight-direction forging, controlling the finish forging temperature and the pressing amount, wherein the forging parameters are shown in the table 1, and as shown in fig. 4, the surface wrinkles of the forged product are basically eliminated.

Example 3(GR9 forging)

By utilizing eight-direction forging to obtain

And (3) forging the cast ingot to a square billet of 300mm, controlling the finish forging temperature, wherein the forging parameters are shown in the table 1, and as shown in fig. 5, the surface wrinkles of the forged product are basically eliminated.

As can be seen from Table 1, the surface quality of GR9 forgings can be greatly improved by using the embodiments 1,2 and 3 of the method.

TABLE 1 forging Process parameters and forging product quality comparison

Number of fire

Amount of depression

Finish forging temperature

Forging method

Furnace temperature setting

Surface quality

Grinding loss weight ratio

Comparative example 1

2

50-70

805

Square forging

1100℃

Is very poor

＞3％

Comparative example 2

3

70-90

823

Eight-side forging

1080℃

Difference (D)

＞1％

Example 1

3

50-70

803

Hexagonal forging

1100℃

Jia

＜1％

Example 2

3

50-70

801

Eight-side forging

1100℃

Superior food

＜0.5％

Example 3

3

50-70

802

Eight-side forging

1120℃

Superior food

＜0.5％

Claims

1. The method is characterized in that the method utilizes forging pressing amount control to improve the finish forging temperature and change the traditional square forging into polygonal forging so as to effectively reduce or eliminate defects of bark lines, cracking and the like on the surface of the titanium alloy forging.

2. The method of improving the surface quality of a titanium alloy forging according to claim 1, wherein the polygonal forging has n sides (n-6, 8,12 …).

3. The method of improving the surface quality of titanium alloy forgings as claimed in claim 1, wherein the titanium alloy can be TA18(GR9), TC4(GR5) or TA10(GR 12).

4. The method for improving the surface quality of the titanium alloy forging as claimed in claim 1, wherein the pressing amount is less than or equal to 70 mm.

5. The method for improving the surface quality of the titanium alloy forging according to claim 4, wherein the pressing amount is 50-60 mm.

6. The method for improving the surface quality of the titanium alloy forging according to claim 1, wherein the finish forging temperature is greater than or equal to 780 ℃, preferably greater than or equal to 800 ℃.

7. The method for improving the surface quality of the titanium alloy forging as claimed in claim 1, wherein the weight of the forging blank is 1-5 tons, and the diameter of the ingot is 300-1000 mm.

8. The method for improving the surface quality of the titanium alloy forging according to claim 1, wherein the temperature of the forging furnace is 1000-1150 ℃, preferably more than or equal to 1100 ℃.

9. The method for improving the surface quality of the titanium alloy forging according to claim 1, wherein the smelting mode is vacuum consumable electrode arc smelting, electroslag smelting, vacuum skull furnace smelting, vacuum non-consumable arc smelting, electron beam smelting, plasma beam (or plasma arc) smelting.

10. The method of claim 1, wherein the billet produced by the method can be used for tandem production of rods, flat materials, wires, coils, pierced billets, extruded tubes, plates, and forged materials.