| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a steel sheet for die quenching which has excellent scale peeling resistance upon hot working. Ž<P>SOLUTION: The steel sheet has a composition containing, by mass, 0.19 to <0.28% C, 0.15 to 0.50% Si, 1.0 to 1.8% Mn, ≤0.025% P, ≤0.001% S, 0.2 to 1.5% Al, ≤0.005% N, 0.01 to 0.15% Ti and 0.0008 to 0.0030% B, and the balance Fe with inevitable impurities. Thus, the generation of scales is suppressed upon heating in die quenching, a load in shot blast treatment can be reduced. Further, the peeling of scales upon hot working in die quenching is suppressed, the damage of a die for die quenching and the generation of linear flaws in the surface of a product are prevented. The deformation of a product after shot blasting is eliminated, and the production of a high-strength component whose dimensional precision is remarkably improved, and having a tensile strength of ≥1,500 MPa is facilitated. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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