| 摘要 |
PROBLEM TO BE SOLVED: To provide a high hardness steel having corrosion resistance of a certain degree, good in cold workability, capable of controlling hardness at the time of quenching to >=58 HRC and moreover, having excellent machinability. SOLUTION: This steel is the one having a compsn. contg., by mass, 0.35 to 0.65% C, <=0.25% Si, <=0.25% Mn, 0.005 to 0.2% S, 4.0 to 11.0% Cr, 0.001 to 0.1% Al, 0.0005 to 0.02% Ca, 0.0005 to 0.01% O, 0.02 to 0.2% N, and the balance substantial Fe and contg. sulfides of >=5μm diameter equivalent to a circle contg. Ca of 0.1 to 10% by >=5 pieces per 3.3 mm2.
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