Patent ID: 9573176
Date: 2017-02-21
CPC Classifications: B21B,B22D,B32B,C21D,C22C

Claim:
1. A surface layer material of a hot rolling mill roll which is adapted to be used for a surface layer of a hot rolling mill composite roll, the material having a chemical composition containing, by mass%, C: 2.4% or more and 3.5% or less, Si: 1.2% or more and 2.4% or less, Mn: 0.2% or more and 2.0% or less, Cr: 0.8% or more and 2.1% or less, Mo: 0.3% or more and 1.1% or less, Ni: 3.0% or more and 7.0% or less, V: 1.2% or more and 2.2% or less, Nb: 0.1% or more and 0.8% or less, REM: 0.0005% or more and 0.1% or less, Al: 0.003% or more and 0.05% or less, and the balance being Fe and inevitable impurities, wherein the contents of C, Cr, V, Nb, REM, and Al satisfy relational expressions (1) and (2) below: where C, Cr, V, Nb, REM, and Al respectively represent the mass% contents of the corresponding chemical elements.