| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stainless steel excellent in pitting corrosion resistance by providing a stainless steel with a composition consisting of specific percentages of C, Si, Mn, Cr, Mo, W, N, Ni, and Cu and the balance Fe. SOLUTION: The high hardness martensitic stainless steel has a composition which consists of, by weight, 0.40-0.60% C, <=2.0% Si, <=2.0% Mn, 11.0-18.0% Cr, Mo or Mo and W in amounts within the range satisfying Mo+1/2W=1.0 to 3.0%, 0.04-0.25% N, 0.1-2.5% Ni, 0.1-3.0% Cu, and the balance Fe and in which Ni and Cu satisfy inequality III and the value of A represented by equation I and the value of B represented by equation II are regulated to <=10 and >=20, respectively. It is also preferable to add one or more elements among B, Mg, Ca, and Al to improve hot workability. By carrying out hardening at >=1,000 deg.C and then low temperature tempering at <=300 deg.C or high temperature tempering at 400-500 deg.C, the high hardness martensitic stainless steel having >=58 HRC hardness can be obtained.
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