Nippon Steel Corporation

Morio Shiozaki

Takahide Shimazu

Hiroyasu Fujii

Shuichi Yamazaki

Yozo Suga

Nobuyuki Takahashi

Hiroaki Masui

Yoshiaki Shimoyama

Takeo Nagashima

Masafumi Okamoto

Kiyoshi Tanaka

Hiromu Fujii

Masahiko Oda

Kohichi Fujiwara

Mitsuaki Kawashima

Nobuoki Ishihara

Takayoshi Inokuchi

Kazuo Nishiura

Hisashi Kabayashi

A grain oriented silicon steel sheet having excellent primary glass film property and magnetic property, comprising 2.0 to 5.0% by weight of Si, wherein a primary glass film formed during secondary recrystallization annealing is composed mainly of forsterite (Mg.sub.2 SiO.sub.4) and an oxide containing Al, mainly of spinel (MgAl.sub.2 O.sub.4), or Al and Si, mainly of cordierite (MgO.sub.2 Al.sub.4 Si.sub.5 O.sub.18) and/or sapphirine (Mg.sub.4 Al.sub.10 Si.sub.2 O.sub.23), and in an analysis of the surface of the steel sheet by glow discharge optical emission spectrometry analysis (GDS analysis), a peak derived from Al is separated from a peak derived from Mg, and, preferably, the peak derived from Al is separated from the peak derived from Mg and the distance (time) from the surface of the steel sheet at which the peak derived from Al is 1.2 times or more the distance from the surface of the steel sheet at which the peak derived from Mg appears.

Grain oriented silicon steel sheet having excellent primary film

An inner shielding material and a method of manufacturing the same, wherein the material comprises a steel sheet 0.10 to 0.25 mm thick of a composition of .ltoreq.0.005% C, .ltoreq.2.0% Si, .ltoreq.0.4% P, 0.1 to 1.0% Mn, 0.01% S, .ltoreq.0.01% sol.Al, .ltoreq.0.01% N and the balance Fe and residual impurities, having a hardness H.sub.v (500 g) of 90 or greater and a grain size of 7 or less when measured by ferrite grain size; and a blackened layer on the surface of the steel sheet comprising primarily FeO formed by transformation of Fe.sub.3 O.sub.4 and having superior adhesion.

Television picture tube inner shielding material having a blackened

In the continuous casting of slabs for use in manufacturing grain-oriented electrical steel sheet and strip, the slag covering the molten steel for casting the slabs is adjusted in its composition to maintain the ratio of Al.sub.2 O.sub.3 to SiO.sub.2 at not less than 0.25, whereby the slabs continuously cast from the molten steel are made free from variation in Al or Al and S content in the direction of casting.

Method for continuously casting slab for manufacturing grain-oriented

A method for preventing edge cracks in a grain oriented silicon steel sheet produced from a continuously cast slab containing 2.5 to 4.0% silicon. This method is carried out with a controlled reduction rate in a rough rolling mill and/or with an adjusted reduction by a pair of edge rolls of an edger.

Method for preventing the edge crack in a grain oriented silicon steel

A continuously cast steel slab for production of a grain-oriented electrical steel sheet having excellent magnetic properties in which at least 95% of the total number of grains constituting an equi-axed crystal zone in said slab has a cross sectional dimension less than 9 mm.sup.2 per one grain.

Continuously cast slabs for producing grain-oriented electrical steel

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Himeji, Japan

Morio Shiozaki