JPS6056020A - Production of light-gauge strip of silicon steel non- oriented in (100) face - Google Patents

Abstract

PURPOSE:To produce a titled light-gauge silicon steel strip having an excellent magnetic characteristic by solidifying quickly a molten steel contg. a specific amt. of Si to a light-gauge strip and subjecting said strip to a homogenizing treatment, rolling and annealing under specific conditions. CONSTITUTION:A molten steel contg. 2.0-8.0wt% Si and consisting of the balance substantially Fe is continuously supplied from a nozzle onto a cooling body moving at a high speed, by which the molten steel is quickly solidified and cooled to a light-gauge strip. The light-gauge strip is first subjected to a homogenizing treatment in a temp. range of 700-1,100 deg.C. The thickness is adjusted by rolling to 10-300mu and thereafter the steel strip is annealed in a temp. range of 1,050-1,800 deg.C. The undesirable deterioration in the magnetic characteristic is thus stably eliminated.

Description

[Detailed Description of the Invention] (Technical Field) Regarding non-oriented silicon steel ribbon, especially when crystal grains < o 0
1> This specification relates to obtaining a (100) in-plane non-oriented silicon steel ribbon having a texture in which the axis is highly concentrated in the normal direction of the plate surface, and thereby having excellent magnetic properties. The technical content described in the book is the process of quenching molten silicon steel with a composition of 812.0~B, Owt % and the balance being substantially ye, and especially its homogenization process (normalizing).
This is a development result that improves the texture through an appropriate combination of rolling and annealing processes, and is positioned in the technical field related to the production and processing of quenched ribbons.

(Background Technique Wl) Today, silicon steel sheets containing about 8 t of Sl are widely used as core materials for electrical equipment such as transformers and motors.

Such silicon steel sheets require hot rolling and cold rolling in the manufacturing process, and grain-oriented silicon steel, which has excellent magnetic properties in the rolling direction, requires even more advanced management technology. Since it was necessary to go through a complicated annealing process, the manufacturing cost is much higher than that of other M types.

On the other hand, in recent years, a direct plate manufacturing method has been developed in which metal ribbon is manufactured by directly rapidly solidifying molten steel.
2.0~s, owt%, more preferably 6~7wt
It is possible to produce silicon steel quenched ribbon containing as high as %, and in this case, compared to the conventional cold-rolled silicon steel sheet mentioned above, the cost is significantly lower, and the production is much easier. In general, although the iron loss of such high-81 content steel quenched ribbons is lower than that of conventional silicon steel cold-rolled sheets, their brittleness is extremely high, and therefore conventional rolling methods are no longer applicable. Because of the incompatibility, until the development of the direct sheet manufacturing method by rapid solidification, no industrial attempt had been made to produce silicon steel sheets containing 4 or more Si.

However, the high-Si quenched ribbon manufactured by the direct plate manufacturing method has large strain and the texture is not suitable in its original state, so in terms of overall magnetic properties it is inferior to conventional silicon steel quenched ribbon. 0 (Summary of prior development) The research group to which the inventors belong previously published Japanese Unexamined Patent Application Publication No. 56-87627, and developed a method for manufacturing directly from Si-containing molten steel. The magnetic properties of the silicon steel quenched ribbon obtained by the plate method are
We proposed a method to eliminate and improve the inferiority of silicon steel cold-rolled thin sheets manufactured through conventional rolling and heat treatment. The subject matter of this method is to perform 8th recrystallization annealing to remove the strain caused by rapid solidification and improve the texture. On the other hand, a patent application filed in 1983, in which most of the inventors participated, was subsequently filed. -2
The specification of No. 05125 clarifies the influence of the thickness and grain size of the quenched ribbon before annealing on the magnetic properties and proposes its effects on rolling.

Or, depending on the polishing method, the plate thickness before annealing can be reduced to 20~80 mm.
It discloses the development results of adjusting the diameter to 0 μm, and to 80 to 200 μm for ribbons in which the average diameter of crystal grains in a plane parallel to the plate surface is 20 μm or more.

In the latter invention, when the plate thickness is adjusted by rolling rather than polishing, the thickness is not necessarily (100 mm) after annealing.
) It does not necessarily result in an in-plane non-directional structure, but sometimes (
100) Hardest to be magnetized in the plane (100) (011
) It was later newly discovered that there are cases where the magnetic properties are deteriorated as a result of accumulation in the azimuth.

(Objective of the Invention) The present invention aims to stably eliminate the new problem found above, that is, the undesirable deterioration of magnetic properties when a quenched ribbon is annealed after rolling. It is a purpose.

That is, according to the prior invention of Patent Application No. 57-205125, a rapidly solidified ribbon is rolled to a thickness of 20 to 800.
In the case of obtaining a silicon steel quenched ribbon product by adjusting the thickness to a thickness of 100 to 1100 μm and then annealing it within a temperature range of 1050 to 1300 °C, the
The basis of this invention is the discovery through experiments that equalization treatment within the temperature range of °C, that is, normalizing, is advantageously suited for the above purpose. (Structure of the Invention) This invention Si2,0-8. Molten steel containing 50% Owt% and the remainder Fe is continuously supplied from a nozzle onto the surface of a cooling body moving at high speed, and is rapidly solidified into a quenched ribbon. First, the molten steel is homogenized within a humidity range of 700 to 1100°C. In-plane (IOQ) material with excellent magnetic properties, characterized in that the plate thickness is adjusted to a thickness of 20 to 800 μm by rolling, and then annealed within a temperature range of 1050 to 1800°C. When a quenched ribbon manufactured by the direct plate manufacturing method, which is a method for manufacturing non-oriented silicon steel ribbon, is annealed, crystal grains grow over time.
Among the crystal grains that have grown to penetrate the plate thickness, under vacuum conditions, the surface energy of the crystal grains with (100) planes parallel to the plate surface is the smallest, and the difference in surface energy is mainly used as the driving force to generate (100) Crystal grains with faces grow large. This is the so-called 8th order recrystallization, and this recrystallization process is affected by the sheet thickness before annealing and the grain size, and the relationship between the optimum sheet thickness and grain size has already been established since 5
This is as described in the specification of No. 7-205125.

Here, the optimum plate thickness for 8th recrystallization is 2 if the average diameter of the crystal grains in the plane parallel to the plate surface is 20 μm or less.
0 to a o o pm, and the crystal structure of this ribbon is a columnar crystal structure that grows from the plate surfaces on both sides to the center, and the direction in which the columnar crystals grow is the <OO1> axis direction in the case of 5i-Fe. It is. Therefore, as a collective organization, approximately (1oo
') (okl).

However, when this ribbon is rolled to adjust its thickness, as the rolling reduction increases, the columnar crystals are crushed and rotated, changing the orientation to (100) (011).
It's becoming more and more.

When this rolled ribbon with a rolling texture of (100)(011) is subjected to vacuum annealing and subjected to eighth-order recrystallization, the (100) )(
011), and the magnetic properties are the worst in the (100) plane. FIG. 1 is a pole figure after eight-order recrystallization of a rolled ribbon with a rolling reduction of 80% and FIG. 2 with a rolling reduction of 50%. When the rolling reduction ratio exceeds 80 (
The degree of integration into (100)(011) increases, and as a result, the texture after the eighth recrystallization also becomes integrated into (100)(011).

This invention is based on the above-mentioned new knowledge, and as a result of repeated various experiments in order to improve such disadvantageous behavior, the following results show that even if rolled under heavy pressure, the (100) in-plane non-uniformity can be achieved. It was discovered that a directional 8th order recrystallized structure could be obtained and this invention was completely developed. In other words, the key is to first normalize the quenched ribbon as a homogenization treatment within the humidity range of 700 to 1100°C after quenching and solidification and prior to rolling, and then rolling and vacuum annealing ( 100) A quenched ribbon product with in-plane non-directional structure is obtained.

Figure 8 shows the rolling reduction rate of 50 after normalizing treatment.
The (110) pole figure after eighth-order recrystallization of the ribbon rolled by ELB is shown.

It can be seen from this that it has a (100) in-plane non-directional structure, but due to the above normalizing treatment, random crystal grains grow and the number of columnar crystals decreases relatively. It is presumed that this is because the accumulation of (100)[011] due to rolling is alleviated.

Therefore, if grain growth occurs and the average diameter exceeds 20 .mu.m, the plate thickness must be adjusted to 80 to 200 .mu.m as described in the specification of Japanese Patent Application No. 57-205125. Further, there is no need for normalizing treatment for ribbons whose grains have grown to an average diameter of 20 μm or more due to insufficient cooling during rapid solidification.

Grain growth begins around 7006C,
As long as the temperature is higher than this, any number of times is fine, but if the temperature exceeds 1100°C, the equipment becomes extremely difficult and costs high, making it difficult to carry out on an industrial scale. The temperature of the treatment is 700-1
100. 'C range is good, and at the same time the distortion caused by rapid solidification is reduced, so there is an accompanying benefit of easier rolling.
Needless to say.

Next, the present invention will be described with reference to embodiments.

Example I A quenched ribbon having a thickness of 200 μm was prepared by a twin roll method from molten steel containing 6.5 wt % of Si and the remainder substantially consisting of Fe. Next, divide this quenched ribbon into two groups,
On the one hand, normalizing treatment was performed continuously at a temperature of 950° C. for 5 minutes in an lr atmosphere.

Both of these two types of quenched ribbons had their surface deposits, adsorbed matter, and oxidized parts removed by pickling, and then rolled to a thickness of 120 mm.
It was finished into a rolled ribbon of μm.

After degreasing both rolled ribbons, a release coating was applied to the surface of the ribbons, and the ribbons were made into coils at a temperature of 1200°C for 8 hours) at a vacuum degree of 2.
．． Vacuum annealing was performed under the conditions of 7 x 10''Pa.

Table 1 shows the presence or absence of normalizing treatment and 1.25T.

- A comparison of the relationship between iron loss WIJ and 5/110 at 50H2 is shown. This quenched ribbon was divided into two groups, and one of the quenched ribbons was continuously subjected to normalizing treatment for 10 minutes at a temperature of 850'C in an H8 atmosphere.

After removing deposits and adsorbed materials on the surfaces of these two types of quenched ribbons by pickling, they were finished into rolled ribbons with a thickness of 190 μm by rolling.

After degreasing both rolled ribbons, a delamination film was applied to the surface of the ribbons, and the ribbons were coiled and heated at a temperature of 1200°C for 5 hours in a vacuum degree of 4.
．． Vacuum annealing was performed under the conditions of OX 10"" Pa.

Table 2 shows the presence or absence of normalizing processing and 1.25T150
Table 2 (Effects of the Invention) As described above, according to the present invention, by performing normalizing treatment, excellent magnetic properties are obtained (200)
An in-plane non-oriented silicon steel ribbon can be advantageously produced.

[Brief explanation of the drawing]

Figure 1 shows (1
10) Pole figure, Figure 2 shows the (1
10) Pole Figure FIG. 8 is a (110) pole figure after the eighth recrystallization after rolling of the normalized quenched ribbon. Patent applicant: Kawasaki Steel Corporation Figure 3

Claims (1)

[Claims] L s, tz, o~8. Including Owt Ji, the remainder is substantially F
The molten steel consisting of e is continuously supplied from a nozzle onto the surface of a cooling body moving at high speed, and the quenched ribbon obtained by rapid solidification is first homogenized within a temperature range of 700 to 1100°C, and then rolled into a plate. It has excellent magnetic properties, characterized by adjusting the thickness to 10-800μm and then annealing within the temperature range of 1050-1800℃.
100) Method for producing in-plane non-oriented silicon steel ribbon.