Microstructure evolution of friction stir processed 2507 duplex stainless steel

Microstructure evolution of friction stir processed 2507 duplex stainless steel was investigated at rotational speed of 400 rpm and traverse speed of 100 mm/min. The microstructural evolution in processed zone was studied by optical microscopy and electron backscattered diffraction. Regions in the stir zone and the thermo-mechanically affected zone experienced different microstructure evolution due to different thermo-mechanical processes. The results showed that static recrystallization, dynamic recrystallization, and dynamic recovery occurred in the processed zone. And the ferrite was occurred the recrystallization prior to the austenite.