MOLYBDENUM-CONTAINING AUSTENITIC STAINLESS STEEL EXCELLENT IN NITRIC ACID CORROSION RESISTANCE IN WELD HEAT-AFFECTED ZONE

摘要

PURPOSE: To produce a molybdenum-containing austenitic stainless steel requiring no secondary treatment such as post weld heat treatment and excellent in nitric acid corrosion resistance in a weld heat-affected zone. ;CONSTITUTION: This steel has a chemical composition consisting of, by weight, ≤0.02% C, ≤0.5% Si, 1-2% Mn, ≤0.03% P, ≤0.01% S, 6-22% Ni, 13-27% Cry 2-3% Mo, ≤0-01% sol-Al, 0.03-0.1% N, ≤0.3% Cup ≤0.0010% B, and the balance Fe with inevitable impurities and satisfying inequality Ni+30(C+N)+0.5Mn-1.1 Cr-1.1Mo%-1.5Si+7.4≥0. It is desirable that, in addition to this composition, an inequality Ni+30(C+N)+0.5Mn+0.8Cr+0.8Mo+1.2Si-31.4≥0 is satisfied. It is more desirable that, in addition of either of the above compositions, B is regulated to ≤0.0005%, and further ≤1.0% (not including an addition-free case), in total, of one or more elements among Ti, Nb, V, Zr, Hf, and Ta are incorporated.;COPYRIGHT: (C)1996,JPO