JPS5842728A - Manufacture of oriented silicon steel having high magnetic characteristics - 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 It is known that grain-oriented silicon steel in sheet form is used in a variety of electrical applications, including the manufacture of transformer cores. This steel is produced by hot rolling followed by cold rolling with or without intermediate annealing. A normalizing treatment is then carried out during which both decarburization and recrystallization are achieved. The steel is then typically coated and texture annealed. After the final texture annealing the oriented silicon Regarding steel, this alloy is characterized by having a secondary recrystallized structure at the (110)(001) position, which has a cube-on-edge orientation (Cube-on-edge orientation).
on-edge orientation).

This sheet-shaped alloy has a single direction of easy magnetization in the rolling direction. Applications of this material In particular, when used in the manufacture of transformer cores, this material
A low core 1oss is desirable.

This is because as iron loss decreases, electrical energy consumption decreases. Reduced core loss can be facilitated by implementing an improved cube-on-edge orientation or crystal structure, which provides superior magnetic properties and, in particular, superior core loss.

It is therefore an object of the present invention to provide a method by which grain-oriented silicon steel can be provided which has a good orientation with respect to the structure of the secondary grains or crystals after microstructural annealing and which results in reduced iron losses. It is.

This and other objects, along with a more complete understanding of the invention, will be obtained from the following description of the examples and drawings.

According to the present invention, it has been found that (i) secondary crystals with good orientation are formed inside the strip facing the surface portion of the IJ tube; According to the method of the invention, as seen in the examples below, after cold rolling and before normalizing and final annealing, if grain-oriented silicon steel is removed from each of its surfaces, When subjected to operations such as pickling to remove at least 6.3 μm, the surface portion of this steel exhibits excellent secondary recrystallization, substantially equivalent to that which typically occurs within the strip. It was found that it would have the characteristics of crystal orientation. This removal operation can be carried out by pickling, preferably using a solution of hydrochloric acid.

As an example to explain the present invention, the following composition (1%)
A grain-oriented silicon steel was used.

Tosumi y possible Main - Needle uB 5A91L o,
o3o o, o340.020 ro, 120 ro5
0.0011 0.0043495 0.043 0.
035 0.020 3.2. ! 1034 0.000
．． ! Samples of the above composition in the form of strips were processed to determine the effect of surface removal caused by pickling on the final magnetic properties after tissue annealing.

The results of processing these samples are shown in Figure 1.1. It's a plea. As can be seen from FIG. 1, sample 1 of this steel was pickled before, during and after the final normalizing process.

Symbols N, Q, and ■] in FIG. 1 indicate the following processing.

N-Standard final normalizing cycle, 802°C (1475
″゛の.

15.3 CfrL (6 inches)/min, dew point 10°C (5
0°F) in 80 N2/20 H2.

Q = rapid heat to 982''C (1 sooF) for i minutes, dew point 10C-(5D'F) in 80 N2/20 H2.

P- Pickling in 50% HCl, S) Remove approximately 13/Z+n (% ε) from each side of the IJ tube.

Prior to tissue annealing, the entire strip sample was coated with MgO
Coated with +0.75 coefficient B, its "I') 1177℃ (
Final tissue annealing was done in 21501 H2. The magnetic properties regarding magnetic permeability and core loss of the sample after final annealing are shown in FIGS. 2 and 6, respectively.

In Figures 2 and 3, the number at each data point represents the measured strip thickness (mil). For the sample shown in FIG. 1, magnetic permeability and iron loss data for the conventionally made material are shown in Table 1 as a comparison with the conventionally made material which is not pickled. 1st
The materials in the table are of the same composition as those tested as listed in FIG.

When compared with the data in Table 1 for conventionally produced Hamura, the magnetic property data presented in Figures 2 and 6 also show that pickling according to the invention before final annealing results in a microstructure. It is clear that this provides a significant improvement in magnetic customization after annealing. More particularly, the sample treatment labeled p 10 Q treatment and designated h in FIG. 1 yields the lowest iron loss; while the sample subjected to the N+P treatment has the highest iron loss. As can be seen from the data in Table 1, N
The iron loss value of the +P-treated sample is very similar to that obtained by the conventional method without pickling.

[Brief explanation of the drawing]

FIG. 1 schematically represents an embodiment of the method of the invention. FIG. 2 is a curve showing the magnetic permeability obtained for the embodiment shown in FIG. FIG. 3 is a curve showing the measured iron loss for the embodiment of FIG. Izumi 2 figure N N+P O+P O+N+P
P 10 N O+P+N P+O+N P+0 and 1 te "self-staining during self-improvement; first time 1 cycle compilation 3 figures

Claims (1)

[Claims] (1) Consisting of the steps of hot rolling, cold rolling with intermediate annealing, normalizing, t6 and final structure annealing,
In a method for producing grain-oriented silicon steel with improved iron loss,
A method for producing grain-oriented silicon steel, characterized in that at least 6.3 μm is removed from each surface of the steel after the cold rolling step and before the normalizing step. (2) At least 3.3 μm from each surface of the steel is removed by pickling.
The manufacturing method described in item 1). (6) The manufacturing method according to claim (2), wherein the pickling is carried out using a hydrochloric acid solution.