Patent ID: 7294212
Filing Date: 2007-11-13
Classification: C21D,C22C

Abstract:
1. A high-strength stainless steel material in the form of a wheel rim consisting essentially of: a composition including less than 0.1% by mass of Cu, 0.1% by mass or more but less than 2.0% by mass of Mo, 0.0005% to 0.0050% by mass of B, 0.02% by mass or less of C, 1.0% by mass or less of Si, 2.0% by mass or less of Mn, 0.04% by mass or less of P, 0.01% by mass or less of S, 0.1% by mass or less of Al, 11% by mass or more but less than 17% by mass of Cr, 0.5% by mass or more but less than 3.0% by mass of Ni, and 0.02% by mass or less of N, so as to satisfy the following equations (1) through (4), wherein, the contents of C, B, N, Si, Mn, Cr, Mo, Ni and Cu are in % by mass, and the remainder essentially consisting of Fe; a structure including 12 to 95% by volume of martensite, and the remainder essentially consisting of ferrite, a tensile strength equal to or greater than 730 Mpa, and a weld-heat-affected zone toughness at −50° C. equal to or greater than 40 J/cm