Effects of Chemical Compositions of Stainless Steel Welding Wire for Automotive Exhaust System Components on Droplet Transfer Phenomenon

19 mass% Cr ferritic stainless steel welding wire has been used for automotive exhaust systems. In proportion as the change of usage condition and variation of base material, the technical need for welding wire has intensified. With regard to solid welding wire, which achieves fine-grained weld metal in MIG welding for ferritic stainless steel, effect of chemical compositions of welding wires on droplet transfer phenomenon has been investigated. Followings were found and confirmed from image analysis and experimental works. (1) It is effective in suppressing the amount of spatter by gas emission from droplet that ΔN [mass%N-{0.519×(mass%Al)+0.292×(mass%Ti)+0.151×(mass%Nb)}] value of welding wire is controlled under 0.01mass%. (2) It is effective in suppressing the amount of spatter by irregular short-circuiting that total amount of Al and Ti content of welding wire is controlled under about 0.1 mass%. (3) Developed welding wire which chemical compositions are controlled appropriately is less spatter and fine-graind.