| 摘要 |
The present invention provides: a wear-resistant steel plate which has excellent low-temperature toughness and in which any portion heated to a low-temperature-tempering embrittlement temperature zone is highly inhibited from cracking; and a process for producing the steel plate. The steel plate has a composition which contains, in terms of mass%, 0.100-0.175% (excluding 0.175%) C, 0.05-1.00% Si, 0.50-1.90% Mn, less than 0.006% P, up to 0.005% S, 0.005-0.100% Al, 0.10-1.00% Cr, 0.005-0.024% Nb, 0.005-0.050% Ti, 0.0003-0.0030% B, and 0.0010-0.0080% N. The microstructure thereof in a position corresponding to 1/4 the plate thickness is either a martensite single-phase structure having an average prior-austenite grain diameter of 20-60 μm or a mixed structure comprising martensite and bainite, the areal content of island-shaped martensite being less than 5% with respect to the whole structure. |
