Dissimilar Metal Joining between Stainless Steel SUS304 and Carbon Steel SS400 Using Plasma Arc Welding Process

This paper aims at studying the process parameters of metal joining of dissimilar metals. The objective is to observe how variation of certain process parameters during plasma arc welding between stainless steel SUS304 and carbon steel SS400 influences the welded joint's metallurgical and mechanical properties. Three parameters are of interest and varied: welding speed of 250, 300 and 400 mm/rnin, shielding gas of Ar99.999^% and Ar95^% + He5%, and welding current from 80 to 120 A. The experiments illustrate optimal results particularly with the welding speed of 400 mm/rnin, welding current of 110 A and shielding gas of Ar95% + He5^%• With Ar95^% + He5^%, a maximum tensile strength of 455.99 MPa in the heat affected zone (HAZ) and better penetration can be gained. Increasing both welding speed and current affects the tensile strength. The quality of the welded joints is significantly affected by variation of the amount of applied shielding gas. Coarse grains with the dendritic structure can be observed in HAZ.