Microstructure and mechanical properties of friction stir welded lean duplex stainless steel

In the present study, microstructures and mechanical properties of a friction stir welded lean duplex stainless steel were examined. The plates with 1.5 mm thickness were welded at a constant rotation speed of 800 rpm and welding speeds of 50, 100 and 150 mm/min using WC-base tool. The results showed that microstructures and mechanical properties of the lean duplex stainless steel joints were significantly affected by welding conditions. Increasing the welding speed decreased the peak temperature and the grain size of the α and γ in the weld zone, and hence, improved hardness value and tensile strength of the stir zone. Tensile specimens were failed from the base metal at the retreating side.