JPH0798975B2 - Method for producing Fe-Ni alloy - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an Fe—Ni-based alloy, and in particular, a permalloy alloy excellent in formability such as deep drawing and a 42Ni-Fe alloy for IC lead frames. The present invention relates to a method for manufacturing a Fe-Ni alloy.

[Conventional technology]

Fe-Ni based alloys include Permalloy based soft magnetic materials and IC
There are 42Ni-Fe alloy (hereinafter referred to as 42 alloy) of lead frame material and low thermal expansion amber type alloy used for shadow masks of cathode ray tubes. These alloys
Permalloy, which is a soft magnetic material that is a metal material that plays an important role in various industrial fields, is composed of Permalloy A (hereinafter referred to as PA) and Permalloy B depending on its components.
(Hereinafter referred to as PB) and so on. PA is 70 by weight
An alloy containing ~ 80% Ni and the balance Fe. This is rarely used at present because the manufacturing process is complicated, it is inconvenient for industrial use, and the AC characteristics are poor.

Currently, this is typically 4% Mo as the third element.
An alloy called Mo permalloy or Cr containing 2
% Added Cr permalloy. Also, PB is by weight
An alloy containing 40 to 50% Ni and the balance Fe. In addition, the amount of Ni contained in permalloy should be appropriately selected depending on the application.
Preceding the% value of Ni, it is called, for example, 45 permalloy, and various kinds of alloys are considered. In addition, 42 alloy, which is known to have a small thermal expansion coefficient and shows a thermal expansion coefficient similar to ceramics such as silicon semiconductor and alumina, and 36Ni, which is known to have a small thermal expansion coefficient in a wide temperature range
-There is Fe amber alloy.

In addition, this inventor has proposed in Japanese Patent Laid-Open No. 60-159157, in which 0.001 to 0.03% B or 0.001 to 0.03% B and 0.005 to 0.3% by weight of Fe-Ni alloy is added. There is also an alloy with the addition of Ti and improved hot workability.

These alloys are processed by selecting various processes such as cold working after hot rolling, annealing and quenching for each purpose. Among them, the ones that are close to this invention technology are:
Permalloy containing 50% Ni by weight is hot-rolled, then sufficiently annealed and cold-worked until it reaches a working ratio of 95-98%, and then 900-1200 above the recrystallization temperature. There is a manufacturing method for obtaining anisotropic 50Ni permalloy having a cubic texture in which the rolling surface is (001) and the rolling direction is [100] by annealing at a temperature of ℃.

[Problems to be solved by the invention]

The above is the conventional technique, but these have common characteristics, but unless there is a special manufacturing method such as cross rolling, there is a degree of difference depending on the annealing before or after product processing (001) [100 ] Has the property that a cubic texture with the orientation is formed.

The cubic texture is a structure that is advantageous for the magnetic properties of soft magnetic materials such as permalloy B, but is also a structure that adversely affects the deep drawability.
As a method of preventing the formation of this cubic texture, it is conceivable to perform cross rolling in the case of plate materials and to perform intermediate annealing at each rolling of about 50% to the final plate thickness in the case of strip products. However, it is not realistic in terms of productivity and economy.

An object of the present invention is to modify the structure of an Fe-Ni alloy from a conventional cubic texture to an α-brass type texture and to produce an Fe-Ni alloy having better formability than at present. Specifically, a small amount of B, which hardly changes the basic properties of the Fe-Ni alloy, is added to the conventional Fe-Ni alloy, and this is combined with cold working and heat treatment, The purpose is to find a method for producing an Fe-Ni alloy having excellent formability. The basic properties of the Fe-Ni-based alloy are, for example, magnetic properties when the Fe-Ni-based alloy is a magnetic material.

[Means for solving problems]

In order to achieve the above-mentioned object of the present invention, the present invention is
An alloy made by adding 0.003 to 0.03% B to a metal consisting of ~ 85% Ni and the balance Fe and unavoidable impurities is cold worked to a rolling ratio of 60% or more in the final rolling step, 900 ° C
Provided is a method for producing an Fe-Ni-based alloy, characterized by forming an α-brass type texture by performing an annealing treatment at 1200 ° C or lower.

[Action]

An alloy made by adding 0.003 to 0.03% B to a metal consisting of 30 to 85% by weight of Ni, the balance being Fe and unavoidable impurities, was sufficiently annealed after hot rolling, and After cold working to 60% or more, by annealing at 900 ° C or more and 1200 ° C or less, an α brass type textured structure (hereinafter α brass typed texture) which is the same texture as 7-3 brass or copper aluminum alloy etc. An Fe-Ni-based alloy having a texture) is obtained.

〔Example〕

 Next, examples of the present invention will be described below.

Fe-Ni alloy having the composition according to the present invention (invention alloy)
Table 1 shows the sample numbers of Fe-Ni alloys (comparative alloys) having a composition not according to the present invention, and the chemical composition expressed in terms of steel type and weight%. Each alloy was hot-rolled and then annealed at 900 ° C, and the final cold-rolled rolling ratio and the cold-rolled product at each rolling ratio were annealed at 900 ° C and 1100 ° C. The result of the inspection of the texture of each alloy and the value of the Erichsen test, and 1100 cold rolled at each rolling rate
Table 2 shows the results of magnetic property tests of the respective alloys annealed at ℃.

In Table 2, the inspection results of the texture are shown by the α mark for the α brass type texture according to the present invention and by the vertical mark for the cubic texture.

The alloys having the composition shown in Table 1 were melted in an atmospheric induction furnace to make ingots of about 10 kg each. This ingot was forged into a slab with a thickness of 15 mm, and then hot rolled to obtain a plate with a thickness of 5.5 mm. This hot-rolled sheet at 900 ℃ 30
After annealing in Ar atmosphere for 1 minute, cold rolling is performed to
It was a 2.8 mm plate. Further, it was annealed at 900 ° C. for 30 minutes in an Ar atmosphere. After that, in order to investigate the effect of the final rolling rate, a 2.8 mm-thick plate was cut to 1.5 mm, 1.0 mm, and 0.5 mm, respectively.
Cold rolling was performed to 4 mm, and four types of plate thickness samples were prepared including the 2.8 mm plate that was not rolled again. Of these plate thickness samples, plate thickness samples other than the 2.8 mm plate thickness sample at 900 ° C for 30 minutes
Annealed in Ar atmosphere. Then, four types of plate thickness samples were cold-rolled to a final plate thickness of 0.2 mm. As a result, 4
2.8 mm, 1.5 mm, 1.0 mm, 0.5 mm of plate thickness samples of each type
Cold rolled to a thickness of 0.2 mm, each with a final rolling ratio of 9
The samples were 3%, 87%, 80% and 60%. Further, these samples were annealed for 2 hours in a hydrogen atmosphere at 900 ° C. and 1100 ° C., which were higher than the recrystallization temperature, and the texture, formability and magnetic properties were examined.

The formability was determined by an Erichsen test for evaluating the deep drawability, and the magnetic measurement was performed using a ring-shaped test piece having a sample size of 45 mm in outer diameter and 33 mm in inner diameter.

These test results are shown in Table 2. Among them, for example, for 42 alloys of sample numbers 3,4,5,8,9 in Table 2,
Examining the relationship between B concentration and texture, it was found that cubic texture (001) [10] was found in samples with B concentration less than 0.003% by weight.
0], 0.003% or more samples, α brass type texture (11
3) [21], (225) and [73] are formed. Similarly, when PA and PB were examined, the same results as in the case of 42 alloy were obtained. This difference in structure is hardly affected by the rolling rate and the final annealing temperature, but the tendency is that the lower the rolling rate and the lower the annealing temperature, the lower the degree of aggregation.

Regarding the results of the Erichsen test, it can be seen from Table 2 that all of the invention alloys and the comparative alloys show higher Erichsen values for the samples having a higher final annealing temperature. Then, in the case of the same steel type, a sample having a higher B content concentration, that is, a sample having an α-brass type texture exhibits a higher Erichsen value than a sample having a low B content concentration.

Generally, the material used for deep drawing has an Erichsen value of
It is said that 9 mm or more is required, but all the samples according to the present invention satisfy that requirement.

Furthermore, for PA and PB, the effect of the difference in texture on the magnetic properties was investigated. The survey is based on the final annealing temperature of 1100.
The test was carried out on samples (sample numbers 1, 2, 6, 7) at ℃. Steel type PA
Value of Tesla for each magnetic characteristic, magnetic flux density and coercive force B ₁₀ / T, H
c / 10 ^-4 T, maximum relative magnetic permeability μm, initial relative magnetic permeability μ _i showed significant difference between sample No. 6 showing cubic texture and sample No. 1 showing α brass type texture. I can't. Regarding PB, the above-mentioned magnetic properties of sample No. 2 showing an α-brass texture are slightly smaller than those of sample No. 7 showing a cubic texture, but there is no practical problem. . Further, looking at the rolling ratio and each magnetic property of each sample,
The higher the rolling rate, the better each magnetic property.

From the above, according to the present invention, a small amount of B that hardly changes the basic properties of the Fe-Ni alloy is added to the Fe-Ni alloy, and cold working of 60% or more is performed in the final rolling step. Then, the Fe-Ni-based alloy with B added thereto was annealed at a temperature higher than the recrystallization temperature thereof, whereby the formability superior to the conventional one was obtained.

Next, the composition of the material of the present invention and the reasons for limiting the rolling conditions and the annealing conditions will be described.

The lower limit of the Ni content is 30% by weight, because the texture targeted by this invention is unique to the austenite structure, and if it is less than 30%, the austenite structure is unstable and the martensite structure precipitates. This is because it becomes easier to form and a completely different texture is formed. The upper limit of the Ni content is 85% by weight, because if the amount of Ni is larger than that, the magnetic properties of the resulting alloy deteriorate, and the usefulness as a Fe-Ni alloy is lost. is there.

The amount of B added is limited to 0.003 to 0.03% by weight because
If it is less than 03%, the effect of transforming into an α brass type texture is not sufficient, and if it exceeds 0.03%, the hot workability of the material is impaired, causing a problem in production.

The reason for limiting the rolling rate to 60% or more in the final rolling step is that the rolling rate lower than that limits the degree of aggregation of the texture and cannot sufficiently fulfill the object of the present invention.

The lower limit of the annealing temperature after the final rolling process was set to 900 ° C because the continuous annealing equipment used in the normal process has a relatively short annealing time of several minutes. This is because sufficient growth of recrystallized grains does not occur at the lower temperature. If sufficient growth of recrystallized grains does not occur, the formability such as deep drawing, which is the object of the present invention, cannot be improved. Further, the upper limit of the annealing temperature is 1200 ℃, 1200
This is because if the temperature exceeds ℃, secondary recrystallization will occur, and the crystal orientation will be remarkably randomized, and the α brass type texture will collapse.

For the steel types PA and PB according to the present invention, selecting the rolling rate in accordance with the required magnetic properties is also a method that can sufficiently achieve the object of the present invention.

〔The invention's effect〕

As explained above, according to the present invention, the α-brass type texture is obtained without changing the basic properties of the Fe-Ni alloy, and the Fe-Ni alloy having excellent formability is produced. can do.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Ebado 4-2 Kojima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Nihon Metallurgical Industry Co., Ltd. (56) Reference JP-A-60-159157 (JP, A) ) JP-A-62-284046 (JP, A) JP-A-62-124264 (JP, A) JP-A-53-146915 (JP, A) JP-A-53-79720 (JP, A) JP-A-62- 63649 (JP, A)

Claims (1)

[Claims] 1. An alloy made by adding 0.003 to 0.03% B to a metal consisting of 30 to 85% by weight of Ni, the balance being Fe and unavoidable impurities, and a rolling ratio of 60% in the final rolling step. A method for producing an Fe-Ni-based alloy, which comprises forming an α-brass type texture by performing an annealing treatment at 900 ° C or higher and 1200 ° C or lower after cold working as described above.