摘要:
A steel contains, by weight: C: 0.3% to 0.5%, Si: 0.1% to 0.5%, Mn: 0.1% to 1%, P: 0.03% or less, S: 0.005% or less, Cr: 0.3% to 1.5%, Mo: 1.0% to 1.5%, Al: 0.01% to 0.1%, V: 0.03% to 0.06%, Nb: 0.04% to 0.15%, Ti: 0 to 0.015%, N: 0.01% or less, the remainder of the chemical composition of the steel being constituted by Fe and impurities or residuals resulting from or necessary to steel production and casting processes. The steel enables to produce seamless tubes with a yield strength after heat treatment of 862 MPa or more which are particularly SSC-resistant.