| 摘要 |
PROBLEM TO BE SOLVED: To attain a stable weld bonded zone by means of simple use and slight labor. SOLUTION: The method of welding two segments, of which the first segment 12 consisted of steel and the second segment 13 consisted of a nickel-base alloy containing an additive element, for example, niobium, to give rise to crack or undesirable mechanical characteristics on the bonded area when bonding with steel, and which are loaded by the heat of the temperatures varying from each other and in which an intermediate layer 18 of the ratio of the additive element gradually decreasing from the inside toward the outside is deposited on the bonding surface disposed for welding to each other of the second segment 13 and thereafter the second segment 13 having the intermediate layer 18 is welded to the first segment 12. The intermediate layer 18 obstructs the concentration increase of the niobium or the concentration increase of the additive element or lessens the concentration increase to the extent that the crazing in the weld bonded zone based on the concentration increase of the niobium is surely averted. |
