Kawasaki Steel Corporation

Jfe Steel Corporation

Osaka Gas Company Limited

Kasasaki Steel Corporation

Kazuhide Ishii

Kunio Fukuda

Susumu Satoh

Tatsuo Kawasaki

Masaaki Kohno

Osamu Furukimi

Takumi Ujiro

Akio Nakashiba

Shoji Dohi

Noriyuki Kuriyama

Souhei Miyazaki

Susumu Sato

Takeshi Yokota

Tomohiro Ishii

Hiroshi Shimizu

Shin Ishikawa

Atsushi Miyazaki

Kazuo Mochizuki

Yoshikazu Kawabata

Chiaki Kato

Junichiro Hirasawa

Masao Yukumoto

Kazuaki Kyono

Shigeru Takano

Kenji Takao

Michiharu Ozawa

Haruhiko Ishizuka

Akira Kawaharada

Takeshi Fujihira

Hiroshi Yaginuma

A ferritic stainless steel sheet having excellent corrosion resistance and a method of manufacturing the steel sheet are provided. Specifically, the ferritic stainless steel sheet of the invention contains C of 0.03% or less, Si of 1.0% or less, Mn of 0.5% or less, P of 0.04% or less, S of 0.02% or less, Al of 0.1% or less, Cr of 20.5% to 22.5%, Cu of 0.3% to 0.8%, Ni of 1.0% or less, Ti of 4&#xd7;(C %+N %) to 0.35%, Nb of less than 0.01%, N of 0.03% or less, and C+N of 0.05% or less, and has the remainder including Fe and inevitable impurities, wherein 240+35&#xd7;(Cr %&#x2212;20.5)+280&#xd7;{Ti %&#x2212;4&#xd7;(C %+N %)}&#x2267;280 is satisfied.

Ferritic stainless steel sheet having excellent corrosion resistance and method of manufacturing the same

A stainless steel separator having gas channels including grooves and projections for fuel cells. The separator has a composition including about 0.03 mass percent or less of carbon; about 0.03 mass percent or less of nitrogen, the total content of carbon and nitrogen being about 0.03 mass percent or less; about 16 mass percent to about 45 mass percent chromium; about 0.5 mass percent to about 3.0 mass percent molybdenum; and the balance being iron and incidental impurities. The separator has a contact resistance of about 100 m&OHgr;&middot;cm or less. Preferably, the projections have an arithmetic average surface roughness Ra in the range of about 0.01 to about 1.0 &mgr;m and a maximum height Ry in the range of about 0.01 to about 20 &mgr;m. The stainless steel separator preferably further includes about 0.001 to about 0.1 mass percent silver. A fuel cell including this separator exhibits a stable output voltage for a long period of time.

Stainless steel separator for fuel cells, method for making the same, and solid polymer fuel cell including the same

A steel composition, in which, Si content is regulated to a given range and Nb and Cu or Ni, Mo are compositively added, and a recrystallization annealing is carried out to form an internal oxide layer just beneath a surface of a steel sheet and a surface oxide simultaneously formed on the surface of the steel sheet is removed by pickling. As a result, the formation of oxides of Si, Mn and the like is considerably decreased on the surface of the steel sheet in a subsequent heating before plating because the above internal oxide layer acts as a diffusion barrier. Thus, there can be obtained high tensile strength hot-dipped steel sheets having a considerably excellent plating property.

High tensile strength hot dip plated steel and method for production thereof

Fe&mdash;cr&mdash;al based alloy foil and method for producing the same

The invention provides hot-rolled steel strips which, after having been acid-pickled, can be directly used. The strips have no Cr-decreasing layer and no shot blasted marks on their surface and have good corrosion resistance. The invention also provides a technique of efficiently producing the hot-rolled steel strips. A steel slab having a Cr content of from 6.0 to 25.0 wt. % is hot-rolled, then coiled at a temperature not higher than 700&deg; C., then optionally quenched in water immediately after the coiling, then annealing in a reducing atmosphere, and thereafter acid-pickled in a solution of nitric acid/hydrochloric acid.

Method for producing chromium-containing hot rolled steel strip

A highly corrosion resistant chromium-containing steel has corrosion resistance and oxidation resistance comparable or superior to those of low Cr-stainless steel (Cr content: 11-13% by weight), and excellent intergranular corrosion resistance not attainable in existing chromium containing steels. However, the steel has such a low Cr content that it is not classified as a stainless steel. A preferred composition on a weight % basis, is: C: 0.015% or less, Si: from more than 1.0% to 2.0%, Mn: 0.5% or less, P: 0.05% or less, S: 0.01 or less, Ni: 0.015% or less, provided that sum of the C content and the N content (C&plus;N): 0.020% or less. Ti: from more than 0.30% to 0.50% in which the contents for Cr, Ti, C and N, that is, &lsqb;Cr&rsqb;, &lsqb;Ti&rsqb;, &lsqb;C&rsqb; and &lsqb;N&rsqb; satisfying the following relation: &lsqb;Ti&rsqb;/(&lsqb;C&rsqb;&plus;&lsqb;N&rsqb;)&gE;64&minus;4&times;&lsqb;Cr&rsqb;, balance of Fe and incidental impurities.

Highly corrosion-resistant chromium-containing steel with excellent oxidation resistance and intergranular corrosion resistance

An austenite stainless steel plate having both excellent surface brightness and superior corrosion resistance, without polishing after finish annealing and pickling for descaling of the strip. The steel plate contains Si 0.02 to 0.2 wt % together with Si oxides at 1.0 wt % or less in the surface layer part in the 10 .mu.m depth from the surface. The depth of the intergranular groove in the surface layer part is 0.1 .mu.m or more to 0.5 .mu.m or less. Furthermore, the steel plate contains Al of 0.005 wt % or less and 0 of 0.006 wt % or less. The Al oxides are contained at 0.1 wt % or less in the surface layer part in the 10 .mu.m depth from the surface.

Method for producing austenitic steel plate with excellent surface

A hot-rolled stainless steel strip contains at least 10 wt % Cr and 1.0 wt % or less of Si, and has a controlled scale thickness of not more than 2.5 .mu.m in the surface layer. The average thickness of the Si-containing oxide layer formed in the scale/alloy substitute interface is 0.1 .mu.m or less. The hot-rolled stainless steel strip is produced by hot rolling at an elongation rate of at least 150 or hot rough rolling to form a sheet bar, descaling by spraying superhigh pressure water to the surface of the sheet bar at an impact pressure (p) of 25 kgf/cm.sup.2 or more and a flow rate density of 0.002 l/cm.sup.2 or more, and then finish rolling so that the maximum reduction ratio per pass satisfies certain disclosed criteria.

Hot-rolled stainless steel strip and method for producing the same

Fe--Cr--Al alloy foil having high oxidation resistance for a substrate catalytic converter. The alloy foil contains about: C: 0.02 wt. % or less, N: 0.02 wt. % or less, Si: 1.0 wt. % or less, Mn: 1.0 wt. % or less, Cr: from 15 to 26 wt. %, Al: from 4.5 to 8.0 wt. %, Sm: from 0.05 to 0.30 wt. %, Zr: from 0.01 to 0.10 wt. %, and Hf: 0.005 wt. % to 0.10 wt. %, the balance consisting of Fe and incidental impurities.

FE-CR-AL alloy foil having high oxidation resistance for a substrate of

A far-infrared emitter of high corrosion resistance is prepared by an oxidizing heat treatment of a body made from a stainless steel of 20-35% by weight of chromium, 0.5-5.0% by weight of molybdenum, up to 3.0% by weight of manganese and up to 3.0% by weight of silicon at 900.degree.-1200.degree. C. to form an oxidized surface film having a thickness of at least 0.2 mg/cm.sup.2. Further, a far-infrared emitter of a high emissivity approximating a black body is prepared by subjecting a body made from a stainless steel of 10-35% by weight of chromium, 1.0-4.0% by weight of silicon and up to 3.0% by weight of manganese to a blasting treatment to roughen the surface followed by an oxidizing heat treatment at 900.degree.-1200.degree. C. to form an oxide film on the surface in the form of protrusions having a length of at least 5 .mu.m.

Far-infrared emitter of high emissivity and corrosion resistance and

A far-infrared emitter of high corrosion resistance is prepared by an oxidizing heat treatment of a body made from a stainless steel of 20-35% by weight of chromium, 0.5-5.0% by weight of molybdenum, up to 3.0% by weight of manganese and up to 3.0% by weight of silicon at 900.degree.-1200 .degree. C. to form an oxidized surface film having a thickness of at least 0.2 mg/cm.sup.2. Further, a far-infrared emitter of a high emissivity approximating a black body is prepared by subjecting a body made from a stainless steel of 10-35% by weight of chromium, 1.0-4.0% by weight of silicon and up to 3.0% by weight of manganese to a blasting treatment to roughen the surface followed by an oxidizing heat treatment at 900.degree.-1200 .degree. C. to form an oxide film on the surface in the form of protrusions having a length of at least 5 .mu.m.

Ear-infrared emitter of high emissivity and corrosion resistance and

A rapidly solidified Fe-Cr-Al alloy foil having excellent anti-oxidation properties, the foil essentially consisting of Cr: about 5 to 30 wt %, Al: about 2 to 15 wt %, Si: about 1.5 to 3 wt %, and REM (Y, Ce, La, Pr, Nd): about 0.07 to 2.0 wt %, the balance being Fe and impurities. The foil may further contain about 0.001 to 0.5 wt % of at least one element selected from the group consisting of Ti, Nb, Zr and V. The foil has a grain size of not more than about 10 .mu.m. Preferably, the rapidly solidified alloy foil has a thickness of about 20 to 200 .mu.m.

Rapidly solidified Fe-Cr-Al alloy foil having excellent anti-oxidation

An oxidation-resistant Fe-Cr-Al steel, having superior workability, oxidation resistance at high temperature and corrosion resistance, has a composition which contains: up to but not more than about 0.05 wt % of C; about 0.1 to about 1.0 wt % of Si; up to but not more than about 1.0 wt % of Mn; from about 3.0 to 7.5 wt % of Cr; from about 4.5 to 6.5 wt % of Al; up to but not more than about 0.05 wt % of N; one or more elements selected from about the group consisting of 1), from about 0.01 wt % to 0.3 wt % of Zr, 2), from 0.01 wt % to 0.3 wt % of Ti, and 3), from about 0.001 wt % to 0.2 wt %, expressed as a total, of Y, La, Ce, Pr, Nd and Hf; and the balance sustantially Fe and incidental inclusions.

Oxidation resistant Fe-Cr-Al steel

A high oxidotion resistance Fe-Cr-Al alloy stainless steel foil suitable for forming catalytic converters, specifically for forming automotive catalytic converters. The alloy includes:

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Chiba, Japan

Kazuhide Ishii