Kawasaki Steel Corporation

Keiji Nishimura

Susumu Satoh

Toshiyuki Kato

Hideo Abe

Michiro Komatsubara

Susumu Okada

Atsuhito Honda

Kazunori Osawa

Ko Matsumura

Yoshio Yamazaki

Akio Tosaka

Kazuaki Kyono

Shigeru Umino

Hiromasa Hayashi

This invention can form a sufficiently internal oxide layer in a surface layer portion of an iron matrix of a steel sheet by hot rolling a base steel and subjecting to a heat treatment at a temperature range of 650-950&deg; C. in an atmosphere substantially not causing reduction while being adhered with a black skin scale irrespectively of a chemical steel composition or production history, or even when a radiation type heating of a radial tube or the like is used in a recrystallization annealing before a hot dipping treatment, and hence excellent hot-dipping property and conversion treating property can be given to a steel sheet for hot dipping.

Methods of producing steel plate, hot-dip steel plate and alloyed hot-dip steel plate

A steel sheet for porcelain enameling having improved press formability and enameling properties comprises particular amounts of C, Mn, B, Cu, Al, O, N, and P or further Ti and Nb and the balance being Fe and inevitable impurities and is produced by hot rolling a slab of steel having a chemical composition as mentioned above as a starting material, cold rolling the resulting hot rolled sheet at a reduction of not less than 70%, and then subjecting the resulting cold rolled sheet to a continuous annealing at a heating temperature of not lower than 800.degree. C. but not higher than A.sub.c3 transformation point.

Steel sheets for procelain enameling and method of producing the same

A formable thin steel sheet such as hot rolled sheet, cold rolled sheet or surface treated sheet comprises not more than 0.003 wt % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, not more than 0.15 wt % of P, not more than 0.020 wt % of S, not more than 0.0045 wt % of O, not more than 0.0020 wt % of N, not more than 0.15 wt % of Al provided that a ratio of Al/N is not less than 30, and the balance being Fe and inevitable impurities, and has not only improved formability for press forming, deep drawing or the like but also improved fatigue resistance as a welded joint.

Method of producing formable thin steel sheets

Method of producing steel sheets for porcelain enameling and the same

A formable thin steel sheet such as hot rolled sheet, cold rolled sheet or surface treated sheet comprises not more than 0.003 wt. % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, not more than 0.15 wt % of P, not more than 0.020 wt % of S, not more than 0.0045 wt % of O, not more than 0.0020 wt % of N, not more than 0.15 wt % of Al provided that a ratio of Al/N is not less than 30, and the balance being Fe and inevitable impurities, and has not only improved formability for press forming, deep drawing or the like but also improved fatigue resistance as a welded joint.

Formable thin steel sheets

A semi-process non-oriented electromagnetic steel strip having low core loss and high magnetic permeability is provided which consists essentially of, in % by weight, up to 0.02% of C, 0.2 to 2.0% of Si, 0.1 to 0.6% of Al, 0.02 to 0.10% of P, 0.5 to 1.5% of Mn, 0.1 to 1.0% of Ni, and optionally up to 0.6% of Cu, and optionally 0.01 to 0.2% of Sb and/or Sn, and a balance of iron and inevitable impurities. Magnetic properties are further improved when it is manufactured by hot rolling a slab having the composition at a temperature of from 1,100.degree. to 1,200.degree. C., completing hot finish rolling at a temperature of at least 700.degree. C. in the austenite region, annealing the strip at a temperature from 800.degree. to 880.degree. C. for at least one hour, cold rolling and annealing the strip, and optionally, skin pass rolling with a reduction of 2 to 12%.

Semi-process non-oriented electromagnetic steel strip having low core

A semi-processed non-oriented electromagnetic steel strip having low core loss and high magnetic permeability is provided which consists essentially of, in % by weight, up to 0.02% of C, 0.2 to 2.0% of Si, 0.1 to 0.6% of Al, 0.02 to 0.10% of P, 0.5 to 1.5% of Mn, 0.1 to 1.0% of Ni, and optionally up to 0.6% of Cu, and optionally 0.01 to 0.2% of Sb and/or Sn, and a balance of iron and inevitable impurities. Magnetic properties are further improved when it is manufactured by hot rolling a slab having the composition at a temperature of from 1,100.degree. to 1,200.degree. C., completing hot finish rolling at a temperature of at least 700.degree. C. in the austenite region, annealing the strip at a temperature from 800.degree. to 880.degree. C. for at least one hour, cold rolling and annealing the strip, and optionally, skin pass rolling with a reduction of 2 to 12%.

Growing community of inventors

Chiba, Japan

Keiji Nishimura