Abstract
Mechanical properties of friction stir welded joints of austenitic stainless steels, SUS301L-1/4H and SUS304, under different heat input conditions were studied. The tool rotation speed was set at 600rpm and the welding speed was changed from 60 to 540mm/min. The tensile strength of the SUS301L-1/4H welded joints is equivalent to that of the base material at the welding speeds of 120 to 300 mm/min. The proper welding condition range is smaller than that for SUS304 which is a typical austenitic stainless steel. This result should be related with the difference in the strengths between SUS301L and SUS304 at a high temperature.