Shiseido Company, Limited

Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Ricoh Company, Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Kazuhiko Adachi

Takashi Maeda

Hideki Fujii

Satoru Sugawara

Akihiro Itoh

Toshihiro Ishii

Kazuhiro Harasaka

Shinichi Teraoka

Fumikazu Hoshi

Yoshihiro Oba

Naoto Sato

Chieko Yamamoto

Toshihide Sasaki

Yoshihiro Ohba

Akihiro Nishimura

Takayuki Yamaguchi

Yoichiro Takahashi

Shunichi Sato

Yuji Uneno

Yoshihiro Misaka

Masaru Abe

Eriko Misawa

Masayuki Shibuya

Sunao Chubachi

Takashi Katsurai

Shigeki Muroga

Kazuyoshi Fujisawa

Kenichi Goshokubo

Masayuki Fujiwara

Yuuichi Fukumura

An austenitic stainless steel according to the present invention has a chemical composition containing, by mass %: C: 0.01 to 0.15%; Si: 2.0% or less; Mn: 3.0% or less; Cr: 10.0 to 20.0%; Ni: 5.0 to 13.0%; N: 0.01 to 0.30%; Nb: 0 to 0.5%; Ti: 0 to 0.5%; and V: 0 to 0.5%, with the balance: Fe and impurities, wherein an average grain size is 10.0 &#x3bc;m or less, a difference in value of an average lattice constant d(={d&#xd7;I+d&#xd7;I+d&#xd7;I+d&#xd7;I}/{I+I+I+I}) of an austenite phase between a surface portion and a center portion is 0.010 &#x212b; or more, and a value of a diffraction peak integrated intensity ratio r (=100&#xd7;&#x3a3;I/&#x3a3;I) at a surface is 95% or more.

Austenitic stainless steel

Martensitic mixed phase stainless steel, which has in well balance between excellent strength and formability and excellent fatigue properties, and is inexpensive, and suitable for spring members, has: a chemical composition comprising C: 0.1-0.4%, Si: at most 2.0%, Mn: 0.1-6.0%, Cr: 10.0-28.0%, N: at most 0.17%, the remainder of Fe and impurities, and a metallurgical structure which includes a ferrite phase and a martensitic phase, and also a retained austenite phase of 5 volume % or less if necessary, and which satisfies a relationship of C/C&#x2267;5.0 where an average value Cof C content existing in the ferrite phase, and an average value Cof C content existing in the martensite.

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Tokyo, Japan

Kazuhiko Adachi