| 摘要 |
Provided are: a thick steel sheet suitable for a member, such as an industrial machine, a conveying device, a transporting device and the like, for which abrasion resistance to rocks, sand, mineral ores, slurry-like materials and the like is required; and a method for producing the thick steel sheet. A thick steel sheet which has a chemical composition containing, in % by mass, 0.200 to 0.350% of C, 0.05 to 0.45% of Si, 0.50 to 2.00% of Mn, 0.020% or less of P, 0.005% or less of S, 0.005 to 0.100% of Al, and at least one element selected from Cu, Ni, Cr, Mo, V, Nb, Ti, B, REM, Ca and Mg, wherein the CI value defined by a specific formula is 40 or more and Fe and unavoidable impurities are contained as a remainder; and which has a steel structure comprising a bainite phase at an area fraction of 60% or more, an island-shaped martensite at an area fraction of 5% or more and less than 20% and a remainder made up by at least one phase selected from a ferrite phase, a pearlite and a martensite phase. A steel having the above-mentioned chemical composition is subjected to hot-rolling and subsequently cooled rapidly to 400 to 650ºC. |
