Sumitomo Metal Industries, Inc.

Nippon Stainless Steel Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Masao Koike

Katsuhiko Maruyama

Shinji Shibata

Yoshiaki Shida

Yoshio Tarutani

Hisao Fujikawa

Taishi Moroishi

Mitsuo Miyahara

Shunichiro Akiyama

Junichiro Murayama

Tomoyuki Sugino

Akihito Yamagishi

Shusuke Kakuchi

Kenji Higuchi

Masayoshi Ogaya

Yutaka Hayashi

A ferritic stainless steel which exhibits improved formability and which is especially useful for making 950.degree. C. or 1000.degree. C. exhaust manifolds is disclosed, the steel composition thereof consisting essentially of, on the basis of weight:

Steel for use in exhaust manifolds of automobiles

A heat-resistant ferritic stainless steel plate or foil having improved toughness as well as workability is disclosed, which consists essentially of:

Ferritic stainless steel plates and foils and method for their production

A process for producing heat-resistant ferritic stainless steel sheet which exhibits improved toughness and productivity is disclosed. The process comprises the following steps:

Process for producing heat-resistant ferritic stainless steel sheet

A ferritic stainless steel containing 12.00-25.00% of Cr, 0.1-2.0% of Cu and 0.2-2.0% of Nb with sulfur being restricted to not greater than 0.02%, preferably not greater than 0.005% is hot rolled with a finishing temperature of 850.degree. C. or less, which is lower than the usual finishing temperature, and the resulting hot rolled steel strip is annealed at a relatively high temperature of 950.degree.-1050.degree. C. The resulting cold rolled steel sheet, though it is less expensive, possesses good formability, ridging resistance, surface appearance and corrosion resistance, and is particularly suitable for making ornamental articles, such as automotive mouldings.

Process for manufacturing ferritic stainless steel sheet having good

A 10-35% Cr ferritic stainless steel stabilized with 0.20-1.00% of Nb wherein Nb%.gtoreq.(8.times.C%+2.0%) with impurities, such as carbon, nitrogen, phosphorous, oxygen and sulfur reduced to given levels is disclosed. By reducing the sulfur content to a level of not greater than 0.002%, preferably less than 0.001% or in cases where copper and/or nickel is added, to a level of not greater than 0.005%, the corrosion resistance of the resulting steel can markedly be improved. Since the ferritic stainless steel of this invention also exhibits a combination of good surface appearance and formability, it can be substituted for certain austenitic stainless steels not only as a general corrosion resistant material, but also as a material for making external automotive trims and so on.

Ferritic stainless steel having good corrosion resistance

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Nishinomiya, Japan

Masao Koike