| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a warm water vessel having excellent corrosion resistance in the weld zone without being accompanied by the increase of cost caused by a back gas seal. <P>SOLUTION: The warm water vessel has an inside face provided with a rear bead formed by subjecting steel materials each having a composition comprising, by mass, ≤0.025% C, ≤1% Si, ≤1% Mn, ≤0.045% P, ≤0.01% S, 0.1 to 1% Ni, >21 to 25% Cr, 0.1 to 2% Mo, 0.02 to 0.3% Al, ≤0.025% N, 0 to 1% Cu and one or more kinds selected from 0.05 to 0.4% Ti and 0.05 to 0.5% Nb, and the balance Fe with inevitable impurities to TIG welding without using a back gas seal, and, in the heat-affected zone of the welded rear face, the concentration of Cr in the steel base in the part where oxide scale soluble in a chloride aqueous solution is formed is ≥16 mass% in the depth region of ≥10 nm from the boundary of the steel base/oxide scale. <P>COPYRIGHT: (C)2008,JPO&INPIT |
