Microstructure and creep property of friction welding in 2205 duplex stainless steel

2205 duplex stainless steel was welded by continuous drive-rotation friction welding．The microstructure evolutions and the distribution of phase in each joint were observed by optical microscope．Nano-indentation technology was used to evaluate the creep properties of the γ and δ phase．The results show that joint zones，including base metal，welded zone and plastic deformation zone，and nano-hardness in the γ phase markedly increases due to the plastical deformation，and the increment rate is faster than that in the δ phase zone．Creep properties of γ and δ phase are described in creep stress exponent n based on，creep stress exponent decreases with rising nano-hardness of γ and δ phase．