To improve high temp. crack resistance, low temp. crack resistance, toughness, strength and corrosion resistance of a weld metal in welding a martensitic stainless steel having good weldability excellent in sour resistance.
Gas shield arc welding is done with using a welding wire, which has a composition consisting of, by weight, 0.05-0.12% C, 0.01-1.0% Si, 0.02-2.0% Mn, 11.0-14.0% Cr, 7.0-10.0% Ni, 1.0-3.0% Mo, ≤0.03% P, ≤0.01 S and the balance Fe with inevitable impurities, further satisfying a ratio of Cr equivalent/Ni equivalent of ≥1.4 to ≤1.8 and a Cr equivalent×Ni equivalent of ≥100 to ≤150, a microstructure of a weld metal is made to a three phase structure of austenitic phase+ferritic phase+martensitic phase, a quantity of the weld metal of Cr%+1.6×Mo% is made by ≥0.3% than that of a base metal.
OKITA SHIGERU
FUJI MASAO
ASAHI HITOSHI
