Investigation of the Effect of Welding Parameters on HAZ of AISI409 Using EBSD

In the present study, microstructural characteristics of tungsten inert gas (TIG) welded AISI409 ferritic stainless steel were studied. The effect of the welding parameters on grain size local misorientation and low angle grain boundaries was investigated. It was found that the base metal has partial recrystallization state. After the joining process due to heating cycle, complete recrystallization followed by severe grain growth in theHAZ. A decrease in the number of low angle grain boundaries in HAZ was observed. Nevertheless the welding plastic strain is an increasing factor for local misorientation and low angle grain boundaries. This investigation shows that the final state of strain is the result of the competition between welding plastic strains and stress relieving from recrystallization.