Jfe Steel Corporation

Ayako Ta

Masataka Yoshino

Mitsuyuki Fujisawa

Akito Mizutani

Yukihiro Matsubara

Keisuke Nakazono

Yukio Kimura

Hiroki Ota

Shuji Nishida

Sumio Kaiho

Nobukazu Kitagawa

Saiichi Murata

A stainless steel sheet has a surface quality in which a core height Sk is 1.50 μm or less, a reduced peak height Spk is 0.20 μm or less, and an areal material ratio Smr2 that separates a reduced dale from a core is 80% or less, where the core height Sk, the reduced peak height Spk, and the areal material ratio Smr2 are as specified in JIS B 0681-2:2018. The stainless steel sheet has a whiteness of 50 or greater and an image clarity of 1% or greater.

Stainless steel sheet and methods for manufacturing the same

Ferritic stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The ferritic stainless steel has: a predetermined chemical composition; a microstructure containing ferrite crystal grains which satisfy at least one of a C concentration of 2Cor more and an N concentration of 2Cor more, the ferrite crystal grains having a volume fraction with respect to a whole volume of the microstructure of 5% or more and 50% or less, where Cand Care respectively C content and N content in the steel in mass %; and a Vickers hardness of 180 or less.

Ferritic stainless steel and process for producing same

Provided is a material for a cold-rolled stainless steel sheet having a chemical composition containing, by mass %, C: 0.01% to 0.05%, Si: 0.02% to 0.75%, Mn: 0.1% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 16.0% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06% and the balance being Fe and inevitable impurities. The material has a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase. A ferrite phase in portions extending from surface layers of front and back surfaces of a steel sheet has an average grain diameter of 20 &#x3bc;m or more and 50 &#x3bc;m or less, and a ferrite phase in a central portion of the sheet includes an unrecrystallized ferrite phase.

Material for cold-rolled stainless steel sheet

Stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The stainless steel comprises: a chemical composition containing, in mass %, C: 0.005% to 0.050%, Si: 0.01% to 1.00%, Mn: 0.01% to 1.0%, P: 0.040% or less, S: 0.010% or less, Cr: 15.5% to 18.0%, Ni: 0.01% to 1.0%, Al: 0.001% to 0.10%, and N: 0.005% to 0.06%, with a balance being Fe and incidental impurities; and a microstructure containing a martensite phase of 1% to 10% in volume fraction with respect to a whole volume of the microstructure.

Stainless steel and production method therefor

Provided is a cold-rolled ferritic stainless steel sheet having a chemical composition that contains, by mass %, C: 0.01% or more and 0.05% or less, Si: 0.02% or more and 0.75% or less, Mn: 0.1% or more and 1.0% or less, P: 0.04% or less, S: 0.01% or less, Al: 0.001% or more and 0.10% or less, N: 0.01% or more and 0.06% or less, Cr: 16.0% or more and 18.0% or less, and the balance being Fe and inevitable impurities. The metallographic structure includes a ferrite phase, in which the average grain diameter is 10 &#x3bc;m or less, in which the proportion of ferrite grains having a grain diameter of 10 &#x3bc;m or more and less than 40 &#x3bc;m is 60% or more, and in which the proportion of ferrite grains having a grain diameter of less than 5 &#x3bc;m is less than 20%.

Cold-rolled ferritic stainless steel sheet

A material for stainless steel cold rolling suitable for producing a cold-rolled stainless steel sheet that has sufficient corrosion resistance and ridging resistance as well as excellent formability and surface properties is provided. The material for stainless steel cold rolling according to the present invention contains, in terms of % by mass, C: 0.007% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, and the balance being Fe and unavoidable impurities, wherein the material has a microstructure that includes 10% to 60% of a martensite phase in terms of area fraction, with the remainder being a ferrite phase, and the martensite phase has a hardness of HV500 or less.

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Chiba, Japan

Ayako Ta