Nippon Steel Corporation

Toshiyuki Suehiro

Masanori Ueda

Shinichi Teraoka

Hideki Oka

Takashi Arai

Eiichiro Ishimaru

Hidehiko Sumitomo

Tetsurou Takeshita

Shunji Shoda

Yoshikatsu Nohara

Shigeru Minamino

Shuichi Inoue

Masayuki Abe

Shigeru Ogawa

Takuji Shindo

Shin-ichi Teraoka

Yoshimori Fukuda

Shin-ich Teraoka

Yuuji Yoshimura

Eiichirou Ishimaru

Osamu Ikegami

This invention aims at producing a cold rolled thin sheet having excellent surface quality from a cast strip of a Cr--Ni type stainless steel cast strip by a thin casting method. The production method of the invention comprises the steps of continuously casting a Cr--Ni type stainless steel to a cast strip having a thickness of not greater than 10 mm by using a continuous casting machine the cast mold wall surface of which moves in synchronism with the cast strip; hot rolling the resulting cast strip at a temperature within the range of 900 to 1,200.degree. C. at a reduction ratio of 10 to 50%; carrying out, subsequently, heat-treatment at a temperature within the range of 1,200 to 900.degree. C. for at least 5 seconds; coiling the hot rolled cast strip at a temperature not higher than 600.degree. C.; descaling the rolled cast strip; cold rolling the cast strip; conducting annealing, pickling or bright annealing; and conducting skin pass rolling, whenever necessary.

Method for producing Cr-Ni type stainless steel thin sheet having

Apparatus for producing strip of stainless steel

Thin cast strip of austenitic stainless steel and cold-rolled sheet in

Austenitic stainless steel sheet having excellent surface quality and

A process for producing a thin sheet of a Cr-Ni-based stainless steel having excellent surface quality and workability is produced by continuously casting a stainless steel represented by 18%Cr-8%Ni steel by means of a continuous casting machine having a mold wall surface that moves in synchronization with a cast strip, effecting rapid solidification at a cooling rate of 100.degree. C./sec or more into a cast strip having a thickness of 10 mm or less; after solidification thereof, initiating cooling of the cast strip from a high temperature at a rate of 100.degree. C./sec or more to 1250.degree. C. and preventing the occurrence of recuperation; holding the cooled cast strip in a temperature range of from over 900 to 1250.degree. C. exclusive for 5 sec to 2 min; and cooling and coiling the cast strip and subjecting the cast strip to annealing, pickling, cold rolling and annealing.

Process for producing thin sheet of Cr-Ni-based stainless steel having

Process for manufacturing thin strip or sheet of Cr-Ni-base stainless

Disclosed is a process for the producing coldrolled strips and sheets of austenitic stainless steel, which comprises preparing a cast strip having a thickness not larger than 10 mm, which is composed of an austenitic stainless steel, by a continuous casting machine, in which the wall surface of a casting mold moves synchronously with the cast strip, and cold rolling the cast strip by a hard rolls having a surface hardness not lower than the Vickers hardness of 600. A preferred embodiment of the present invention is characterized in that crystal grains of the cast strip are made finer by cooling the cast strip at a cooling rate of at least 50.degree. C./sec in the temperature range of from the temperature for initiation of solidification of the cast strip to 1200.degree. C. and the cast strip is then coldrolled by the hard rolls, another preferred embodiment of the present invention is characterized in that the hard rolls are composed of a material having a Young's modulus of at least 30000 kgf/mm.sup.2 and the cast strip is cold-rolled by such hard rolls, and another preferred embodiment of the present invention is characterized in that for cast strip which is descaled by pickling, especially with nitric and fluoric acid, prior to cold rolling, the cast strip is cooled at a cooling rate of at least 10.degree. C./sec in the Cr carbide-precipitating temperature range of from 900.degree. to 550.degree. C.

Process for producing cold-rolled strips and sheets of austenitic

A process for producing a cold-rolled strip or sheet of an austenitic stainless steel, comprising the steps of: casting a melt of an austenitic stainless steel into a cast strip in the form of a thin strip having a thickness of 10 mm or less by using a continuous caster in which a casting-mold wall is moved synchronously with the cast strip; cold-rolling the cast strip to form a cold-rolled strip; final annealing the cold-rolled strip; and skin-pass-rolling the annealed strip at an elongation of from 0.5 to 2.5%.

Process for producing cold-rolled strip or sheet of austenitic stainless

Process for production of Cr-Ni type stainless steel sheet having

Growing community of inventors

Hikari, Japan

Toshiyuki Suehiro