| 摘要 |
A hot water container produced by TIG-welding steel members having a composition which contains by mass at least one of C: 0.025% or below, Si: 1% or below, Mn: 1% or below, P: 0.045% or below, S: 0.01% or below, Ni: 0.1 to 1%, Cr: more than 21% to 25%, Mo: 0.1 to 2%, Al: 0.02 to 0.3%, N: 0.025% or below, Cu: 0 to 1%, Ti: 0.05 to 0.4% and Nb: 0.05 to 0.5% with the balance consisting of Fe and unavoidable impurities to each other without back gas seal and having penetration beads on the inside surface, wherein the Cr concentration of steel basis material in an area which exists within the heat-affected zone on the back face side of welding and in which oxidation scale soluble in an aqueous solution of a chloride is formed is 16% by mass or above in the depth region of 10nm or above from the interface between the steel basis material and the oxidation scale. |
