Nippon Steel Corporation

Takeo Nagashima

Shuichi Yamazaki

Yoshiyuki Ushigami

Hiroyasu Fujii

Kei Tanemoto

Takao Kanai

Yozo Suga

Hiroaki Masui

Saburo Ayusawa

Masaya Tsutsumi

Osamu Tanaka

Katsuro Kuroki

Nobuyuki Takahashi

Tadashi Nakayama

Yasunari Yoshitomi

Kenzo Iwayama

Morio Shiozaki

Kenichi Yakashiro

Hisashi Kabayashi

Yosuke Kurosaki

Katsurou Kuroki

Grain oriented silicon steel sheet on which is formed an insulating coating having a thickness that is not less than 2.5 .mu.m that imparts tension to the steel sheet which does not have an inorganic mineral layer formed during a final annealing step (glass film) and a method of forming on grain oriented silicon steel sheet an insulating coating that is not less than 2.5 .mu.m thick and which imparts tension to the steel sheet which does not have the inorganic mineral layer (glass film) that forms during finish annealing, and a method of forming a tensioning insulating coating on grain oriented silicon steel sheet which has been finish annealed and does not have an inorganic mineral surface layer (glass film), after first forming a layer of SiO.sub.2 not less than 0.001 .mu.m thick on the oriented silicon steel sheet.

Grain oriented silicon steel sheet having low core loss and method of

Grain oriented electrical steel sheet having specular surface

Low core loss oriented electrical steel sheet having a surface coating that has a Young's modulus that is not less than 100 GPa and a differential of thermal expansion coefficient relative to the sheet base metal that is not less than 2.times.10.sup.-6 /K and which contains not less than 10 percent, by weight, of crystallites with an average size of not less than 10 nm and an average crystal grain diameter that does not exceed 1000 nm, and a method of manufacturing same.

Oriented electrical steel sheet having low core loss and method of

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

A process for producing a grain-oriented electrical steel sheet having a low watt loss, in which a steel strip consisting, in wt %, of 0.8 to 4.8 Si, 0.012 to 0.050 acid-soluble Al, 0.01 or less N, and the balance consisting of Fe and unavoidable impurities is cold-rolled to a final thickness of 0.15 mm or less, primary-recrystallization annealed, applied with a annealing separator containing magnesia as a major component by electrostatic spray painting, and then final-texture annealed.

Process for producing grain-oriented electrical steel sheet having low

A method of producing grain-oriented electrical steel sheet with a very high magnetic flux density, is characterized by increasing the partial pressure of the N.sub.2 in the annealing atmosphere at the intermediate stage between the start and the finish of the secondary recrystallization, and by ensuring the temperature differential in the coil does not exceed 100.degree. C. during changes to the annealing atmosphere. In addition, the rate of temperature increase at the hottest part of the coil is kept to a maximum of 13.degree. C./hr at least part of the time the coolest part of the coil is between 850.degree. C. and 1100.degree. C.

Method for producing grain-oriented electrical steel sheet with very

A steel sheet having a two-layer film which exhibits excellent lubricating properties under press working can be manufactured by one step coating. In this case the coating composition after being applied to the sheet is irradiated with ionizing radiant energy, i.e., radioactive ray or electromagnetic wave, in an atmosphere containing an oxidizing substance. The outermost layer obtained is an uncured or unhardened semi-fluid layer but the layer contacting the surface of the steel sheet is a cured or hardened resin layer. If a lubricant is incorporated in the coating composition, or if the main component of the coating composition has one double bond per molecule, the result is more advantageous.

Method for the manufacture of a steel sheet having excellent lubricating

A hot-rolled coil having excellent adaptability for pickling can be produced by applying to the sides of the hot-rolled coil, a compound of an alkaline metal or alkaline earth metal, or an oxygen compound of boron, germanium, tin, antimony, lead, bismuth or vanadium. One or more of the aforesaid compositions when applied to a hot-rolled coil serves to suppress the formation of oxide film on the surface of the coil and/or promotes the solubility of the oxide film in the pickling tanks to the extent such oxide film does form.

Method for the manufacture of a hot-rolled coil having excellent

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Futtsu, Japan

Takeo Nagashima