Patent ID: 9090957
Filing Date: 2015-07-28
Classification: C21D,C22C

Abstract:
1. A tempering-omitted martensitic stainless steel seamless oil country tubular good, comprising, by mass, 0.005% to 0.1% C, 0.05% to 1% Si, 1.7% to 5% Mn, at most 0.05% P, at most 0.01% S, 9% to 13% Cr, at most 0.13% Ni, at most 2% Mo, at most 2% Cu, 0.001% to 0.1% Al, and 0.001% to 0.1% N, with the balance being Fe and impurities, said oil country tubular good having a Cr-depleted region under the surface, which is a part having a Cr concentration of 8.5% or less by mass in a region from a surface to a depth of less than 100 μm toward an inside of the tempering-omitted martensitic stainless steel seamless oil country tubular good.