Jfe Steel Corporation

Katsuhisa Yamauchi

Yasushi Kato

Kunio Fukuda

Shin Ishikawa

Takumi Ujiro

Mitsuyuki Fujisawa

Hiroki Ota

Chikara Kami

Reiko Sugihara

Takayoshi Yano

Takako Yamashita

Hideya Matsumoto

Hideya Furusawa

Provided is a ferritic stainless steel that has good corrosion resistance and which exhibits good brazeability when subjected to high-temperature brazing with a Ni-containing brazing filler metal. The ferritic stainless steel has a composition containing, in mass %, C: 0.003 to 0.020%, Si: 0.05 to 0.60%, Mn: 0.05 to 0.50%, P: 0.04% or less, S: 0.02% or less, Cr: 17.0 to 24.0%, Ni: 0.20 to 0.80%, Cu: 0.01 to 0.80%, Mo: 0.01 to 2.50%, Al: 0.001 to 0.015%, Nb: 0.25 to 0.60%, and N: 0.020% or less, with the balance being Fe and incidental impurities, the composition satisfying formula (1) below and formula (2) below,Cu+Mo&#x2265;0.30&#x2003;&#x2003;(1)4Ni&#x2212;(Si+Mn)&#x2265;0&#x2003;&#x2003;(2)(wherein Cu and Mo in formula (1) and Ni, Si, and Mn in formula (2) each represent the content (mass %) of the corresponding element).

Ferritic stainless steel

Provided is a ferritic stainless steel having a chemical composition containing, in mass %: 0.003% to 0.025% of C; 0.05% to 1.00% of Si; 0.05% to 1.00% of Mn; 0.04% or less of P; 0.01% or less of S; 16.0% to 23.0% of Cr; 0.20% to 0.80% of Cu; 0.05% to 0.60% of Ni; 0.20% to 0.70% of Nb; 0.005% to 0.020% of N; and the balance being Fe and incidental impurities, in which a nitrogen-enriched layer is present that has a nitrogen concentration peak value of 0.03 mass % to 0.30 mass % at a depth of within 0.05 &#x3bc;m of a surface of the steel.

Ferritic stainless steel and process for producing same

A steel sheet for a brake disc contains, on a mass percent basis, 0.02% or more and less than 0.10% C, 0.6% or less Si, more than 0.5% and 2.0% or less Mn, 0.06% or less P, 0.01% or less S, 0.05% or less Al, 11.0% to 13.5% Cr, 0.01% to 0.30% Ni, 0.10% to 0.60% Nb, 0.03% or more and less than 0.10% N, more than 0.0010% and 0.0060% or less B, and the balance being Fe and incidental impurities, and the steel sheet after quenching has a hardness of 32 HRC to 40 HRC on a Rockwell hardness scale C (HRC).

Steel sheet for brake disc, and brake disc

A material for brake discs has temper softening resistance sufficient to maintain a hardness of HRC 31 or more after tempering at 700&#xb0; C. for one hour. The low-carbon martensitic chromium-containing steel contains 0.02% to 0.10% of carbon and 0.02% to 0.10% of nitrogen, the total content of carbon and nitrogen being 0.08% to 0.16%; 0.5% or less of silicon; 0.1% or less of aluminum; 0.3% to 3.0% of manganese; 10.5% to 13.5% of chromium; 0.05% to 0.60% of niobium and 0.15% to 0.80% of vanadium, the total content of niobium and vanadium being 0.25% to 0.95%; 0.02% to 2.0% of nickel; and 1.5% or less of copper, and has an Fp value (=&#x2212;230C+5Si&#x2212;5Mn&#x2212;6Cu+10Cr&#x2212;12Ni+32Nb+22V+l2Mo+8W+10Ta+40A1&#x2212;220N) of 80.0 to 96.0, a hardness after quenching of HRC 31 to 40, and a hardness after tempering at 700&#xb0; C. for one hour of HRC 31 or more.

Low-carbon martensitic chromium-containing steel

Growing community of inventors

Tokyo, Japan

Katsuhisa Yamauchi