Patent ID: 9677160
Date: 2017-06-13
CPC Classifications: C21D,C22C

Claim:
1. A low C-high Cr high strength martensitic stainless steel tube for oil and natural gas wells having a yield strength of 862 to 965 MPa, wherein said steel tube consists of, in percent by mass, 0.027 to 0.05% C, 12 to 16% Cr, 1.0% or less Si, 2.0% or less Mn, 5.0 to 7.5% Ni, 1.5 to 3.5% Mo, 0.01 to 0.05% V, 0.02% or less N, 0.01 to 0.06% Ta, and optionally 0.1% or less Nb, the remainder being Fe and unavoidable impurities and satisfies the following formula (1)