摘要 |
A highly corrosion resistant high strength stainless steel pipe for linepipe, having a composition containing about 0.001 to about 0.015% C, about 0.01 to about 0.5% Si, about 0.1 to about 1.8% Mn, about 0.03% or less P, about 0.005% or less S, about 15 to about 18% Cr, about 0.5% or more and less than about 5.5% Ni, about 0.5 to about 3.5% Mo, about 0.02 to about 0.2% V, about 0.001 to about 0.015% N, and about 0.006% or less O, by mass, so as to satisfy (Cr+0.65Ni+0.6Mo+0.55Cu-20C>=18.5), Cr+Mo+0.3Si-43.5C-0.4Mn-Ni-0.3Cu-9N>=11.5) and (C+N<=0.025). Preferably quenching and tempering treatment is applied to the pipe. The composition may further contain about 0.002 to about 0.05% Al, and may further contain one or more of Nb, Ti, Zr, B, and W, and/or Cu and Ca. The microstructure preferably contains martensite, ferrite, and residual gamma.
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