| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel sheet for heat treatment, free from the occurrence, in the course of a heat treatment stage such as quench-and-temper stage, of peeling of the oxide scale formed by heating in the air at the time of heat treatment. SOLUTION: This steel sheet for heat treatment has a composition containing 0.3-1.2% C, 0.1-1.8% Si, and 0.3-2.0% Mn and further containing, independently or in combination, 0.1-2wt.% Cr and 0.1-2wt.% Ni. Moreover, the depth of the open recesses formed by acid pickling of the intergranular oxidized part in the surface layer part of the steel sheet is 3-20μm, and the number of the open recesses is 10-200 pieces per 1000μm line segment length. It is preferable to regulate the ratio of the depth of the open recesses to the thickness of the oxide scale formed by heating at the time of heat treatment toι1. By this method, a heat treated product excellent in surface quality can be obtained, and reduction of manufacturing costs and maintenance of work environment can be attained.
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