Patent ID: 11827949

Abstract:
The invention provides a martensitic stainless steel seamless pipe for oil country tubular goods having high strength, and excellent sulfide stress corrosion cracking resistance and a method for manufacturing the same. The martensitic stainless steel seamless pipe for oil country tubular goods has a yield stress of 655 to 758 MPa, and has a composition containing, in mass %, C: 0.10% or less, Si: 0.5% or less, Mn: 0.05 to 2.0%, P: 0.030% or less, S: 0.005% or less, Ni: 4.0 to 8.0%, Cu: 0.02% or more and less than 1.0%, Cr: 10.0 to 14.0%, Mo: 1.0 to 3.5%, V: 0.003 to 0.2%, Co: 0.02% or more and less than 1.0%, Al: 0.1% or less, N: 0.1% or less, Ti: 0.50% or less, and the balance Fe and incidental impurities, wherein C, Mn, Cr, Cu, Co, Ni, Mo, W, Nb, N, and Ti satisfy the predetermined relations.