| 摘要 |
PROBLEM TO BE SOLVED: To provide an abrasion resistant steel having superior abrasion resistance combined with toughness, and to provide a manufacturing method therefor. SOLUTION: The steel comprises, by mass%, 0.05-0.40% C, 0.1-0.8% Si, 0.5-2.0% Mn, 0.05% or less P, 0.02% or less S, 0.005-0.5% Ti, 0.0005-0.005% B, one or more elements among Cu, Ni, Cr, Mo, Nb and V, as needed, and the balance Fe with unavoidable impurities; has a surface layer comprising substantially martensitic structure in as quenched state; and has a central part of sheet thickness comprising substantially a tempered martensitic structure, a tempered bainitic structure, or the mixed structure thereof. The manufacturing method comprises rolling the steel having the above composition, cooling it to the Ms point or lower from the Ar<SB>3</SB>point or higher at a cooling rate of 10°C/s or higher, then heating it to the Ac<SB>3</SB>point or higher at a programming rate of 1°C/s or higher, and cooling it to the Ms point or lower from the Ar<SB>3</SB>point or higher at a cooling rate of 10°C/s or higher. COPYRIGHT: (C)2005,JPO&NCIPI
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