Effect of current on characteristic for 316 stainless steel welded joint including microstructure and mechanical properties

Abstract

Gas Metal Arc Welding (GMAW) process is a clean and cost effective process in arc welding which is higher productivity and good in quality. In this study, 316 stainless steel pipes with outside diameter is 73mm and 7.0mm thickness were joint using Tungsten Inert Gas (TIG) welding process. Various current settings were used to obtain the optimum joint characteristics and minimize defects that will contribute to cost effective. Mechanical characteristics of the welded alloys were carried out is tensile tests and hardness (HV). Metallographic examination was conducted to identify and observe the various fusion zones. Results show that the increase of welding current bring about the large amount of heat input in the welding pool, the enlargement of width and deepness of the welding pool, cumulative sigma phase in the matrix and reducing the chromium carbide percentage in 316 stainless steel welded joint. Arc current of 100A has been identified of the most suitable current since it gives the lowest defects and brings the highest value of strength and hardness for this material.