Nippon Steel & Sumikin Stainless Steel Corporation

Nippon Steel Stainless Steel Corporation

Atsutaka Hayashi

Junichi Hamada

Nobuhiko Hiraide

Masatoshi Abe

Yoshiharu Inoue

Masaharu Hatano

Hiroyuki Matsuyama

Norihiro Kanno

Kazuhisa Matsumoto

Shigeo Fukumoto

Shigeru Kaneko

Haruki Ariyoshi

The present invention has as its technical problem to prevent cracking when producing a steel sheet by ferritic stainless steel sheet and provide a ferritic stainless steel sheet excellent in toughness and a part using the same. To solve this technical problem, the present invention provides steel comprised of, by mass %, C: 0.001 to 0.030%, Si: 0.01 to 1.00%, Mn: 0.01 to 1.00%, P: 0.010 to 0.050%, S: 0.0002 to 0.0100%, Cr: 10.0 to 20.0%, N: 0.001 to 0.030%, Nb: 0.10 to 0.40%, B: 0.0002 to 0.0030%, Al: 0.005 to 0.100%, and a balance of Fe and unavoidable impurities in which the amount of solute Nb being less than or equal to a smaller value of 0.20 and (Nb content-0.08) mass %.

Ferritic stainless steel sheet, method for producing the same, and part

This ferritic stainless steel includes: in terms of % by mass, C: 0.001% to 0.100%; Si: 0.01% to 5.00%; Mn: 0.01% to 2.00%; P: 0.050% or less; S: 0.0100% or less; Cr: 9.0% to 25.0%; Ti: 0.001% to 1.00%; Al: 0.001% to 5.000%; and N: 0.001% to 0.050%, with a balance being Fe and impurities, wherein in a region from a steel surface to a depth of 5 nm, and not exceeding a thickness of a passive film, a total amount of Al and Si is 1.0 atomic % or more, an amount of Cr is 10.0 atomic % or more, and an amount of Fe is 85.0 atomic % or less, in terms of cation fraction.

Ferritic stainless steel having excellent salt corrosion resistance

This ferritic stainless steel sheet contains, by mass %: C: 0.001% to 0.020%; Si: 0.01% to 4.00%; Mn: 0.01% to 3.00%; P: 0.010% to 0.040%; S: 0.0001% to 0.0100%; Cr: 10.0% to 15.0%; N: 0.001% to 0.020%; Al: 0.50% to 10.0%; and either one or both of Ti: 0.05% to 0.40% and Nb: 0.05% to 0.40%, with the balance being Fe and unavoidable impurities, in which Cr/(Si+Al) is 10.0 or less, and a specific gravity is 7.6 g/cmor less.

Ferrite-based stainless steel sheet having low specific gravity and production method therefor

A steel material contains, in mass %, C: 0.005 to 0.050, N: 0.05 to 0.30, Si: 0.1 to 1.5, Mn: 0.1 to 7.0, P: 0.005 to 0.100, S: 0.0001 to 0.0200, Cr: 18.0 to 28.0, Cu: 0.1 to 3.0, Ni: 0.1 to 8.0, Mo: 0.1 to 5.0, Al: 0.001 to 0.050, B: 0.0001 to 0.0200, and Ca: 0.0001 to 0.0100. An area ratio of an austenitic phase ranges from 30% to 70% and formulae (I) and (II) below are satisfied.1.03&#x2264;[% Cr*F]/[% Cr]&#x2264;1.40&#x2003;&#x2003;Formula (I)1.05&#x2264;[% Mn*A]/[% Mn]&#x2264;1.80&#x2003;&#x2003;Formula (II)[% symbol of an element]: a content of the element in the steel[% symbol of an element*F]: a content of the element in a ferrite phase[% symbol of element*A]: a content of the element in the austenitic phase

Ferritic-austenitic two-phase stainless steel material and method for manufacturing same

This ferritic stainless steel contains, by mass %, C: 0.001% to 0.030%; Si: 0.01% to 1.00%. Mn: 0.01% to 2.00%, P: 0.050% or less, S: 0.0100% or less, Cr: 11.0% to 30.0%, Mo: 0.01% to 3.00%, Ti: 0.001% to 0.050%, Al: 0.001% to 0.030%, Nb: 0.010% to 1.000%, and N: 0.050% or less, with a remainder being Fe and inevitable impurities, wherein an amount of Al, an amount of Ti, and an amount of Si (mass %) satisfy Al/Ti&#x2265;8.4Si-0.78.

Ferrite-based stainless steel with high resistance to corrosiveness caused by exhaust gas and condensation and high brazing properties and method for manufacturing same

A stainless steel exhibiting an excellent brazeability includes in mass %: C: from 0.001% to 0.1%; Si: from more than 1.5% to 4.0%; Mn: from 0.05% to 4.0%; Cr: from 10.5% to 30%; Ni: 35% or less; N: from 0.001% to 0.4%; one or both of Ti: 0.002% to 0.030% and Al: 0.002% to 0.10%; and a balance being Fe and inevitable impurities, in which an Si content, a Ti content and an Al content satisfy Formula 1, and an oxide film with a composition satisfying Formula 2 is formed on a surface of the stainless steel,Si/(Ti+Al)&#x2265;40&#x2003;&#x2003;Formula 11.2&#xd7;SiFe&#x2264;Si/Fe&#x2264;5&#xd7;Si/Fe&#x2003;&#x2003;Formula 2in Formula 1 and Formula 2, a suffix 'f' expresses the oxide film in a unit of atom %, and a suffix 'm' expresses a base material in a unit of mass %.

Stainless steel having excellent brazeability

A ferritic stainless steel for a fuel cell includes, in mass %, Cr: 11 to 25%, C: 0.03% or less, Si: 2% or less, Mn: 2% or less, Al: 0.5 to 4.0%, P: 0.05% or less, S: 0.01% or less, N: 0.03% or less, Ti: 1% or less, and a balance composed of Fe and unavoidable impurities. Furthermore, in the ferritic stainless steel, the maximal concentration of Al in a surface of the ferritic stainless steel is 30 mass % or more in cation ion fraction excepting O in an depth direction region having twice a thickness of an oxide film having less than 0.1 &#x3bc;m.

Ferritic stainless steel for fuel cell and method for producing the same

This ferritic stainless steel sheet contains, by mass %: C: 0.02% or less, N: 0.02% or less, Si: 0.05% to 0.80%, Mn: 0.05% to 1.00%, P: 0.04% or less, S: 0.01% or less, Cr: 12% to 20%, Cu: 0.80% to 1.50%; Ni: 1.0% or less, Mo: 0.01% to 2.00%, Nb: 0.30% to 1.00%, Ti: 0.01% to less than 0.25%, Al: 0.003% to 0.46%, V: 0.01% to less than 0.15%, and B: 0.0002% to 0.0050%, with a remainder of Fe and inevitable impurities, wherein the following formulae (1) and (2) are satisfied, and an average Cu concentration in an area from a surface to a depth of 200 nm is 3.00% or less,

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Tokyo, Japan

Atsutaka Hayashi