METHOD FOR WELDING DUCTILE CAST IRON AND STAINLESS STEEL AND WELDING STRUCTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a weld joining technique between a ductile cast iron and a stainless which can reduce the hardness at the weld zone and improve the fatigue strength at the weld zone. SOLUTION: An SUS430 JIL steel pipe 12 having 48.6 mm outer diameterϕand 1 mm thickness (t) is inserted into a ductile cast iron-made flange 11 having 4 mm thickness (t) near the weld zone and the whole peripheral MIG welding is executed by using a nickel alloy welding material of Y Ni Cr-3 as the welding material 13. Annealing treatment is executed to this welded structural member at 700 deg.C for 1 Hr in a heating furnace.