HIGH STRENGTH STAINLESS STEEL PIPING HAVING OUTSTANDING RESISTANCE TO SULPHIDE STRESS CRACKING AND RESISTANCE TO HIGH TEMPERATURE CARBON DIOXIDE CORROSION.

摘要

High strength stainless steel piping which contains as mass%, C ≤0.05%, Si ≤ 1.0%, P ≤ 0.05%, S 0.002%, Cr 16% and ≤18%, Mo 2% and ≤ 3%, Cu 1%-3.5%, Ni ≥3% and 5%, Al 0.001%-0.1% and O ≤0.01%, and also Mn ≤1% and N in the region of ≤0.05%, where Mn and N satisfy equation (1), with the remainder comprising Fe and impurities, wherein the metal structure is mainly a martensite phase, with a ferrite phase of 10-40% v/v and a residual γ phase of ≤10% v/v. This high strength stainless steel piping has adequate corrosion resistance in an environment of high temperature carbon dioxide and has outstanding resistance to sulphide stress cracking at normal temperatures      [Mn] x ([N] - 0.0045) ≤0.001 (1) where the symbols for the elements in equation (1) represent the quantities of each element in the steel (units: mass%).