| 摘要 |
PURPOSE:To prevent occurrence of pitting corrosion, stress corrosion cracking, intergranular corrosion, etc. in a weld heat-affected zone by depositing a metal nobler than a parent metal on the zone and heat diffusing the nobler metal to the parent metal side with welding heat to form a passivation film. CONSTITUTION:Noble metal 4 such as palladium is deposited on a joining portion of austenitic steel, titanium clad or the like within a range where welding heat is affected before or immediately after backing plate 1 and clad 2 are welded by fillet welding or other method. Metal 4 is heat diffused to the surfaces of plate 1 and clad 2 with welding heat to form a strong passivation film. Since the noble metal is used only at the heat-affected zone apt to undergo local corrosion, manufacture of equipment and welding can be performed easily. |
