MODELING MICROSTRUCTURE DEVELOPMENT IN WELD METALS

Microstructure development in the weld metal region is controlled by v arious physical processes such as thermochemical reactions in liquid, solidification, and solid state transformation. There is a need for fu ndamental and generalized models that can predict the effect of these physical processes on microstructure development in a wide variety of alloy systems during welding processes. This paper describes certain a dvances made in the area of modeling the microstructure development in low-alloy steel, stainless steel, and Ni-base superalloy. In addition , this paper describes the importance of advanced analytical technique s for fundamental understanding of phase transformation mechanisms in welds.