HIGH CORROSION RESISTANT MARTENSITIC STAINLESS STEEL LOW IN HARDNESS IN WELD ZONE

摘要

PROBLEM TO BE SOLVED: To produce a martensitic stainless steel having the hardness in the heat affected zone equal to that of the base metal and having excellent CO₂ corrosion resistance. ;SOLUTION: This high corrosion resistant martensitic stainless steel is the one having a compsn. contg., by weight, ≤0.005% C, 0.1 to 1.0% Mn, ≤0.03% P, ≤0.005% S, 1.5 to 5% Ni, 1 to 3% Cu and 9 to 13% Cr, also satisfying the relation of 40C+34N+Ni+0.3Cu-1.1Cr≥-10.5, moreover contg., at need, 0.5 to 2.0% Mo and one or ≥ two kinds among Ti, Zr, Ca and rare earth metals, and the balance substantially Fe and having a martensitic structure, and in which the hardness of the heat affected zone is low comparably to that of the base metal, or is the one obtd. by subjecting the same to tempering or two phase region tempering. Thus, the martensitic stainless steel excellent in the characteristics in the heat affected zone which is nearly impossible in the conventional steel and good in CO₂ corrosion resistance can be obtd.;COPYRIGHT: (C)1997,JPO