Nippon Steel Corporation

Satohiro Hayami

Fumio Matsumoto

Takashi Furukawa

Tadashi Nakayama

Munetsugu Matsuo

Kunihide Takashima

Toshio Kikuma

Tsutomu Haratani

Tadao Nozawa

Takaaki Yamamoto

Ryoji Terakado

Hiroshi Hayakawa

Soichi Izumi

Yoshihiko Takeoka

Tadatzugu Yabuta

Jun Imamura

In the secondary recrystallization of a grain-oriented silicon steel sheet, a specific temperature gradient is generated, thereby developing the secondary recrystallized grains having a good (110) [001] orientation and increasing the magnetic flux density higher than that previousy obtained. The temperature gradient is established at the boundary region between the primary and secondary recrystallized regions, with the result that highly oriented (110) [001] secondary recrystallization nuclei preferentially are caused to develop.

Process for producing grain-oriented electromagnetic steel sheet

In a process for the production of a grain-oriented silicon steel strip, a slab is heated, hot-rolled, cold-rolled, and subjected to a decarburization annealing and secondary recrystallization annealing steps. Grain coarsening is likely to occur during the high temperature heating and remain in the final product as streaks. The secondary recrystallization is, therefore, incomplete due to the streaks. In the hot rolling, an asymmetric flow, is applied to the steel, so as to eliminate the streaks and, hence, to obtain excellent magnetic properties.

Process for producing grain-oriented silicon steel strip

A slab or ingot of ferritic stainless steel for deep drawing applications is subjected to hot rolling, coiled at 450.degree. to 750.degree. C, subjected to warm rolling without cooling the coil by a rolling mill installed separately from the hot strip rolling mill, subjected to continuous annealing, and subjected to cold rolling and final annealing.

Method for the manufacture of a ridging-free ferritic stainless steel

A method for producing a steel sheet of dual-phase structure composed of ferrite phase and transformed phase (or phases) produced by rapid cooling, which comprises isotropically dispersing a carbon concentrated phase by a pretreatment of the steel sheet and continuously annealing the steel sheet thus pretreated in the alpha-gamma range, followed by cooling at a rate not larger than about 10000.degree. C/min., as defined herein.

Method for producing a steel sheet with dual-phase structure composed of

A silicon-containing high strength steel sheet having isotropic high ductility and toughness in all directions independently of the rolling direction comprising 0.03 to 0.15% C, 0.7 to 2.3% Si, 0.7 to 2.0% Mn with the balance being iron and unavoidable impurities, in which the ratio of Si/Mn is between 0.6 and 1.5 and the content of S is maintained in an amount as low as possible below that normally contained as an unavoidable impurity.

Isotropic and high-strength high silicon steel sheet

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Yokohama, Japan

Satohiro Hayami