JPS5928523A - Cube-on-edge oriented silicon steel and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cube-on-edge grain-oriented silicon steel and to a silicon steel produced by this method.

Cube on Edge
-on-edge) Grain-oriented silicon steels are known for many electrical applications, including transformer cores. Cube on Two "Tsuji" About silicon steel, this alloy is (110) [
There is a feature of secondary recrystallization at the position [001], and this position is called Cube-on-edge.
It is called position. This material in sheet form has a direction of easy magnetization in the direction of rolling. Applications of this material, particularly when used in the manufacture of transformer cores, reduce iron loss.
This material requires a low watt loss as electrical energy consumption decreases over time. Reduced power loss can be facilitated by obtaining fine sized secondary crystals during the annealing process.

L, 4. - The purpose of the present invention is to provide a method in which cube-on-edge silicon steel is given a fine secondary grain or crystal structure after annealing and a low watt loss is obtained, as well as a silicon steel produced by this method. The goal is to provide the following.

This and other objects of the invention will be better understood from the following description and specific examples.

For the cube-on-edge silicon steel of the present invention, the steel is conventionally produced by hot rolling followed by one or more cold rolling operations with intermediate annealing. After cold rolling, the steel undergoes a normalizing operation to achieve primary recrystallization and decarburization. Usually, normalizing temperature is 704 to 871°C (1300 to 1600°C)
°F). According to the invention, after normalizing, the steel is subjected to a 'cold deformation, such as by a cold rolling operation. After cold deformation, this steel is annealed in the usual way to achieve secondary recrystallization. It has been found that by carrying out room temperature deformation according to the present invention after normalizing and before standard annealing, the growth of secondary condensation U during final standard annealing can be suppressed and the watt loss can be reduced.

It has been found that cold rolling, which achieves an elongation within 0.5 to 15%, preferably within 0.5 to 4.7%, is effective for this purpose. It has been found that the size of the crystals after annealing can be adjusted by varying the amount of reduction between 2M. Although the method of the present invention is generally useful for cube-on-edge silicon steels,
Particularly suitable for this type of steel within the following composition limits:

Steel Wn C5SX-1
40,025-0,0450,020-0,0600,
005-O3X-110,050-0,0800,02
0-0,0600,020-D sx-14 as an example
The compositions of the two molten steels (He and 153595) of the indicated alloys are 1% by weight and are as shown below.
n G S F3i1
5A6BA O,0360,0280,0193,
211535950,0380,0250,0203,
25-1(16-8i B Fg0
402.70-3.500.0005-0.0030 balance, 0353.00-3.70 balance No. 154684 BFε 0.0011 balance 0.0013 balance This material is conventionally processed by hot rolling followed by cold rolling operation. It is well processed. This material was then subjected to a final normalization process consisting of continuous annealing at 1475'l' (800°C) to aid decarburization and result in first-strike crystallization. The normalized steel in the form of strips was cut into lengths suitable for cold rolling and rolled in a cold C4 heavy cold rolling mill. The extent of plastic deformation was determined by measuring the percent elongation over a 24 inch (61 m) span drawn on the 14 strips before cold rolling. A sample of this steel was retained prior to cold rolling for comparison purposes.

The material was cut into standard Epstein strip samples and roller coated with MgO and 0.75% B slurry water.

Finish annealing was carried out in dry wood leaves. The annealing cycle consists of charging the steel to a furnace at 760°C (1400"F), heating at 28°C (50'F) for 1 hour to 1175°C (below 2150), heating at 1175°C (2150'F) for 20 minutes. This consisted of time holding and furnace cooling. After this standard annealing operation, magnetic tests and crystal size measurements were carried out. The joint properties and crystal size of the tested materials are shown in Table 1.

~T Kuma no ℃ mai ma he r d %j W +j W ″
Shouzeku Kawakuni ○ Qllr:IL
.

The method of the present invention reduces both the magnetic permeability in high induction rails as well as the crystal size formed during finishing roughening. Current trends in electrical steel usage are toward lower induction, and significant improvements have been made in reducing sheet thickness by 50% to lower core or watt losses. Commercially available materials usually have a thickness of 0.6
5 to 0.2 Bxx(0,014 to 0.(11
1 inch), preferably 0.26 mm (0.009 inch) or less.

Since such materials are used at low inductions of 15 kilogauss or less, magnetic permeability at high induction becomes less important in electrical devices.

First, the core loss resulting from eddy currents during crushing as the sheet thickness decreases appears to be more dependent on the crystalline size of the material, ie, the core loss decreases as the crystalline size decreases. The method of the present invention is extremely important in the production of thin sheets with a thickness of 0.38 mm to 0.1 mm (0.015 inch to 0.004 inch), and is therefore suitable for use in transformers. This is an advantage of the present invention.

W Applicant Allegheny Ludlum Steel Corporation

Claims (1)

[Claims] (1) A method for producing a cube-on-edge grain-oriented silicon steel with reduced watt loss, which comprises the steps of hot rolling, cold rolling with intermediate annealing, and final standard annealing. A method for manufacturing silicon steel, characterized in that, prior to said final tempering, the steel is normalized and then deformed at room temperature to bring about decarburization and primary recrystallization. ('2J) The method according to claim (1), wherein the cold deformation includes at least one cold rolling operation. A method according to claim (2), in which the 41 m is normalized at a temperature in the range of 704°C to 871°C. Method (5) Cube-on-edge grain-oriented silicon steel with a thickness of less than 0-38iu, including the steps of hot rolling, cold rolling with intermediate smoothing and final roughening. Then, prior to the final tempering, the steel was normalized and then deformed at room temperature to bring about decarburization and primary amorphous crystals.
A silicon steel manufactured by a process characterized by: