Patent ID: 7566373
Filing Date: 2009-07-28
Classification: C21D,C22C,Y02P

Abstract:
1. A rolling member comprising: a first quench hardened layer which is formed on a surface layer of the rolling member and has a parent phase taking the form of martensite phase containing carbon of 0.35 to 0.8 wt %; and a second quench hardened layer which is formed at a deeper layer under said first quench hardened layer and has a parent phase containing at least either one of martensite phase or bainite phase containing carbon of 0.07 to 0.3 wt % and has a cementite dispersed therein a content of 2 to 20% by volume, wherein said rolling member is made of a steel containing carbon of 0.4 to 1.5 wt % and Cr of 2 wt % or less, and wherein said steel contains one or more elements of Mn of 0.1 to 2 wt %, Si+Al of 0.05 to 1.5 wt %, Mo of 0.7 wt % or less, W of 1.4 wt % or less, V of 2 wt % or less, Al of 1 wt % or less, Ni of 3 wt % or less, B of 0.01 wt % or less, Ti+Nb+Zr of 1 wt % or less and S of 1.0 wt % or less.