阅读说明：本技术 一种超导线材用Nb47Ti合金大规格棒材的锻造方法 (Forging method of Nb47Ti alloy large-size bar for superconducting wire ) 是由 杨晶 张胜 张奕 尚金金 何龙龙 李少强 王凯旋 刘向宏 于 2020-11-26 设计创作，主要内容包括：本发明公开了一种超导线材用Nb47Ti合金大规格棒材的锻造方法,包括：对Nb47Ti合金铸锭进行第一火次锻造,第一火次锻造过程包括三次镦粗、拔长,锻后进行冷却；将开坯锻造后的Nb47Ti合金铸锭进行第二火次锻造,第二火次锻造过程包括拔长、摔圆,锻后进行冷却；将中间锻造后的Nb47Ti合金铸锭采用径锻机进行第三火次锻造,锻后进行冷却,得到Nb47Ti合金大规格棒材。通过选择变形方式、变形设备及变形量,缩短锻造火次及生产周期,进而降低成本,能得到低倍组织均匀模糊、高倍组织均匀细小的大规格Nb47Ti合金大规格棒材。(The invention discloses a forging method of a Nb47Ti alloy large-size bar for a superconducting wire, which comprises the following steps: carrying out first hot forging on the Nb47Ti alloy cast ingot, wherein the first hot forging process comprises three times of upsetting and drawing out, and cooling after forging; performing secondary forging on the cogging-forged Nb47Ti alloy ingot, wherein the secondary forging process comprises drawing out and rounding, and cooling after forging; and performing third fire forging on the Nb47Ti alloy cast ingot subjected to intermediate forging by using a radial forging machine, and cooling after forging to obtain the Nb47Ti alloy large-specification bar. By selecting the deformation mode, the deformation equipment and the deformation amount, the forging heat number and the production period are shortened, the cost is further reduced, and the large-specification Nb47Ti alloy bar with uniform and fuzzy macrostructure and uniform and fine macrostructure can be obtained.)

1. A forging method of a Nb47Ti alloy large-size bar for a superconducting wire is characterized by comprising the following steps:

step 1, cogging and forging:

carrying out first hot forging on the Nb47Ti alloy ingot, wherein the first hot forging process comprises three times of upsetting and drawing out, and cooling after forging;

step 2, intermediate forging:

performing secondary forging on the Nb47Ti alloy ingot subjected to cogging forging in the step 1, wherein the secondary forging process comprises drawing out and rounding, and cooling after forging;

step 3, forging a finished product:

and (3) performing third fire forging on the Nb47Ti alloy cast ingot subjected to intermediate forging in the step (2) by using a radial forging machine, and cooling after forging to obtain the Nb47Ti alloy large-specification bar.

2. The method for forging a large-sized Nb47Ti alloy bar for a superconducting wire according to claim 1, wherein the first upsetting and drawing forging ratio in step 1 is controlled to 1.3 to 1.8, and the second upsetting and drawing forging ratio in step 1 is controlled to 1.5 to 2.1.

3. The forging method of the Nb47Ti alloy large-size bar for the superconducting wire as claimed in claim 1, wherein the heating temperature of the first hot forging in step 1 is 1150-1200 ℃, and the heating time is 10-14 h.

4. The method for forging a large-sized Nb47Ti alloy rod for a superconducting wire according to claim 1, wherein the drawing and rounding forging ratio in step 2 is controlled to 2.0-3.0.

5. The method of claim 1, wherein the second hot forging in step 2 is performed at a temperature of 950 ℃ to 1000 ℃.

6. The method for forging large-sized Nb47Ti alloy rods for superconducting wires according to claim 1, wherein in the third-fire forging step of step 3: the forging ratio is controlled to be 3.0-4.0, the radial forging comprises 4 deformation passes, and the deformation of each pass is 1.0-2.2.

7. The method of claim 1, wherein the heating temperature of the third hot forging in step 3 is 850-920 ℃.

Technical Field

The invention belongs to the technical field of non-ferrous metal processing methods, and relates to a forging method of a Nb47Ti alloy large-size bar for a superconducting wire.

Background

The Nb47Ti alloy bar is an important raw material for preparing the superconducting wire, and because the superconducting wire is extremely harsh in use environment, the structural uniformity of the Nb47Ti alloy bar is highly required. The traditional Nb47Ti alloy bar is forged by sawing and blanking an ingot, and upsetting and pulling the ingot for multiple times after heating to improve the uniformity of blank structures.

Disclosure of Invention

The invention aims to provide a forging method of a large-size Nb47Ti alloy bar for a superconducting wire rod, which solves the problem of cost increase caused by excessive forging in the prior art.

The technical scheme adopted by the invention is that the forging method of the Nb47Ti alloy large-size bar for the superconducting wire comprises the following steps:

step 1, cogging and forging:

carrying out first hot forging on the Nb47Ti alloy cast ingot, wherein the first hot forging process comprises three times of upsetting and drawing out, and cooling after forging;

step 2, intermediate forging:

performing secondary forging on the Nb47Ti alloy ingot subjected to cogging forging in the step 1, wherein the secondary forging process comprises drawing out and rounding, and cooling after forging;

step 3, forging a finished product:

and (3) performing third fire forging on the Nb47Ti alloy cast ingot subjected to intermediate forging in the step (2) by using a radial forging machine, and cooling after forging to obtain the Nb47Ti alloy large-specification bar.

The invention is also characterized in that:

in the step 1, the forging ratio during the first upsetting and drawing is controlled to be 1.3-1.8, and the forging ratio during the second upsetting and drawing is controlled to be 1.5-2.1.

In the step 1, the heating temperature of the first hot forging is 1150-1200 ℃, and the heating time is 10-14 h.

And 2, controlling the forging ratio of drawing and rounding to be 2.0-3.0.

The heating temperature of the second hot forging in the step 2 is 950 ℃ to 1000 ℃.

The invention has the beneficial effects that:

according to the forging method of the Nb47Ti alloy large-size bar for the superconducting wire, the ingot can be guaranteed to be subjected to integral plastic deformation by performing integral cogging forging on the Nb47Ti alloy ingot, and the coarse as-cast structure in the ingot is effectively crushed; the blank is drawn out and rounded, so that tissues at different parts of the blank are relatively uniform; the radial forging machine is used for radially forging the bar stock, so that different parts of the bar stock can be guaranteed to obtain homogenized structures; by selecting the deformation mode, the deformation equipment and the deformation amount, the forging heat number and the production period are shortened, the cost is further reduced, and the large-size Nb47Ti alloy bar for the superconducting wire with uniform and fuzzy macrostructure, uniform and fine macrostructure and the diameter of more than or equal to phi 165mm can be obtained.

Drawings

FIG. 1 is a bar microstructure sampling position diagram obtained by a forging method of a Nb47Ti alloy large-sized bar for a superconducting wire rod according to the present invention;

FIG. 2 is a graph showing the X-ray film imaging results of a bar obtained by a forging method of a large-sized Nb47Ti alloy bar for a superconducting wire according to an embodiment of the present invention;

FIG. 3a is a microstructure diagram of the edge portion of a large-sized Nb47Ti alloy rod for a superconducting wire according to an embodiment of the forging method of the rod;

FIG. 3b is a R/2 position microstructure diagram of a bar obtained by an example of a forging method of a large-sized Nb47Ti alloy bar for a superconducting wire according to the present invention;

FIG. 3c is a center microstructure of a Nb47Ti alloy large-sized bar according to an embodiment of the forging method for a superconducting wire of the present invention;

FIG. 4 is a graph showing the X-ray film imaging results of a bar obtained by a second example of the forging method of a large-sized Nb47Ti alloy bar for a superconducting wire according to the present invention;

FIG. 5a is a microstructure diagram of the edge portion of a large-sized Nb47Ti alloy rod according to an example of the forging method of the large-sized Nb47Ti alloy rod;

FIG. 5b is a R/2 position microstructure diagram of a bar obtained by a second forging method of a Nb47Ti alloy large-sized bar for a superconducting wire according to the present invention;

FIG. 5c is a center position microstructure of a large-sized Nb47Ti alloy rod according to example II of the forging method for a superconducting wire rod.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

A forging method of a Nb47Ti alloy large-size bar for a superconducting wire rod comprises the following steps:

step 1, cogging and forging:

carrying out first-time forging on the Nb47Ti alloy ingot, wherein the heating temperature of the first-time forging is 1150-1200 ℃, the heating time is 10-14 h, then discharging, upsetting the ingot to a set size, carrying out first-time upsetting and drawing on the ingot, and controlling the forging ratio to be 1.3-1.8 to ensure that the surface quality of the blank is good; then carrying out second upsetting and third upsetting and drawing out on the cast ingot, controlling the forging ratio to be 1.5-2.1, further crushing cast crystal grains and homogenizing the structure of the blank, and cooling after forging;

step 2, intermediate forging:

performing secondary forging on the Nb47Ti alloy ingot subjected to cogging forging in the step 1, wherein the heating temperature of the secondary forging is 950-1000 ℃, discharging, sequentially performing drawing-out and rounding treatment, controlling the forging ratio to be 2.0-3.0, cooling after forging, and enabling the tissues of different parts of the blank to be relatively uniform through rounding;

step 3, forging a finished product:

and (3) performing third-time forging on the Nb47Ti alloy cast ingot subjected to the intermediate forging in the step (2) by using a radial forging machine, wherein the heating temperature is 850-920 ℃, the forging ratio of the third-time forging is controlled to be 3.0-4.0, the radial forging comprises 4 deformation passes, the deformation of each pass is 1.0-2.2, the uniform deformation of different parts of the bar can be ensured by designing the deformation of each deformation pass in the radial forging process, and cooling is performed after forging to obtain the Nb47Ti alloy large-size bar.

Through the mode, the forging method of the Nb47Ti alloy large-size bar for the superconducting wire can ensure that the cast ingot is subjected to integral plastic deformation and effectively breaks the coarse cast structure in the cast ingot by carrying out integral cogging forging on the Nb47Ti alloy cast ingot; the blank is drawn out and rounded, so that tissues at different parts of the blank are relatively uniform; the radial forging machine is used for radially forging the bar stock, so that different parts of the bar stock can be guaranteed to obtain homogenized structures; by selecting the deformation mode, the deformation equipment and the deformation amount, the forging heat number and the production period are shortened, the cost is further reduced, and the large-specification Nb47Ti alloy bar with uniform and fuzzy macrostructure and uniform and fine macrostructure can be obtained.

Example 1

Step 1, cogging and forging:

carrying out first-time forging on the Nb47Ti alloy ingot, wherein the heating temperature of the first-time forging is 1160 ℃, discharging after the heating time is 10 hours, carrying out first-time upsetting and drawing out on the ingot, and controlling the forging ratio to be 1.4; then carrying out second upsetting and third upsetting and drawing-out on the cast ingot, controlling the forging ratio to be 1.7, and cooling after forging;

step 2, intermediate forging:

performing secondary forging on the Nb47Ti alloy ingot subjected to cogging forging in the step 1, wherein the heating temperature of the secondary forging is 980 ℃, drawing out the ingot from the furnace, sequentially performing elongation and rounding treatment, controlling the forging ratio to be 2.7, and cooling the ingot after forging;

step 3, forging a finished product:

and (2) performing third-time forging on the Nb47Ti alloy cast ingot subjected to the intermediate forging in the step 2 by using a radial forging machine, wherein the heating temperature is 900 ℃, the forging ratio of the third-time forging is controlled to be 4.0, the radial forging comprises 4 deformation passes, the deformation amount of each pass is 1.2, 1.6, 1.9 and 1.1, and cooling is performed after forging to obtain the Nb47Ti alloy large-specification bar with the specification of phi being 193.7 mm. As can be seen from FIGS. 3a to 3c, the microstructure of the bar is more uniform from the edge to the center, indicating that the forging deformation of the bar is more uniform and sufficient.

Example 2

Step 1, cogging and forging:

carrying out first-time forging on the Nb47Ti alloy ingot, wherein the heating temperature of the first-time forging is 1200 ℃, discharging the ingot after the heating time is 12 hours, and carrying out first-time upsetting and drawing out on the ingot, wherein the forging ratio is controlled to be 1.7; then carrying out second upsetting and third upsetting and drawing-out on the cast ingot, controlling the forging ratio to be 1.5, and cooling after forging;

step 2, intermediate forging:

performing secondary forging on the Nb47Ti alloy ingot subjected to cogging forging in the step 1, wherein the heating temperature of the secondary forging is 950 ℃, discharging, sequentially performing drawing-out and rounding treatment, controlling the forging ratio to be 2.3, and cooling after forging;

step 3, forging a finished product:

performing third-time forging on the Nb47Ti alloy cast ingot subjected to intermediate forging in the step 2 by using a radial forging machine, wherein the heating temperature is 870 ℃, the forging ratio of the third-time forging is controlled to be 3.6, the radial forging comprises 4 deformation passes, the deformation of each pass is 1.1, 1.4, 1.8 and 1.3, and cooling is performed after forging to obtain a Nb47Ti alloy large-specification bar with the specification of phi being 204mm, as shown in FIG. 4, the bar has uniform low-order structure and no defects such as streamline and the like, so that the bar is fully deformed; as can be seen from FIGS. 5a to 5c, the microstructures of the bar are uniform from the edge to the center, indicating that the forging deformation of the bar is uniform and sufficient.