WEAR-RESISTANT STEEL SHEET HAVING EXCELLENT WELDED PART TOUGHNESS AND LAGGING DESTRUCTION RESISTANCE PROPERTIES.

摘要

Disclosed is a wear-resistant steel sheet which has excellent toughness of a multi-layer-welded part and excellent lagging destruction resistance properties and is therefore suitable for a construction machine, an industrial machine and the like. Specifically disclosed is a steel sheet which contains, in mass%, 0.20-0.30% of C, 0.05-1.0% of Si, 0.40-1.2% of Mn, 0.010% or less of P, 0.005% or less of S, 0.40-1.5% of Cr, 0.005-0.025% of Nb, 0.05-1.0% of Mo, 0.005-0.03% of Ti, 0.1% or less of Al, 0.01% or less of N and 0.0003-0.0020% of B, optionally contains at least one element selected from W, Cu, Ni, V, REM, Ca and Mg, and fulfils the requirements represented by the following formulae: DI* (= 33.85—(0.1—C)0.5—(0.7—Si+1)—(3.33—Mn+1)— 0.35—Cu+1)—(0.36—Ni+1)—(2.16—Cr+1)—(3—Mo+1)—(1.75—V+1) —(1.5—W+1)): 45-180 and C+Mn/4-Cr/3+10P = 0.47, wherein the microstructure of the steel sheet contains martensite as the matrix phase.