LOW CHROMIUM-CONTAINING STAINLESS STEEL EXCELLENT IN THE CORROSION RESISTANCE OF REPEATEDLY WELDED HEAT-AFFECTED ZONE, AND PRODUCING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide the most suitable low chromium-containing stainless steel excellent in a grain boundary corrosion resistance of a welded part even under severe corrosive atmosphere and at the same time, without precedingly generating the corrosion in the heat affecting part near the welding fusion line and further, excellent in the productivity by preventing the deterioration of the corrosion resistance at the welded part, in the case of welding the low chromium-containing stainless steel using martensitic deformationat repeatedly (multi-passes).;SOLUTION: The low chromium-containing stainless steel excellent in the grain boundary corrosion resistance in the heat-affecting part with the multi-pass welding and excellent in the precedent corrosion resistance near the fusion line in the welded part, is composed by mass% of ≤0.03% C, 0.004-0.02% N, 0.03-1% Si, 1.5-2.5% Mn, ≤0.04% P, ≤0.03% S, 10-15% Cr, 0.2-1.5% Ni, 0.005-0.1% Al and further, 4×(C%+N%)-0.35% Ti and the balance Fe with inevitable impurities and the contents of respective elements are to be satisfied to the following formulas;γp=420×C%+470×N%+23×Ni%+9×Cu%+7×Mn%-11.5×Cr%-11.5×Si%-12×Mo%-23×V%-47×Nb%-49×Ti%-52×Al%+89≥80% and the formula; Ti%×N%0.004.;COPYRIGHT: (C)2009,JPO&INPIT