MODELLING AND EXPERIMENTS OF SOLIDIFICATION OF AISI 304

Abstract

In the first part of this paper the solidification of AISI 304 is simulated by means of the multicomponent phase selection theory to predict which phase forms first when the molten alloy is solidified either ä or ã. The eventual ä– ã transition that may occur in AISI 304-type steels has influence on cracking tendency being increased at high solidification velocities. It has been shown that alloys solidified as primary ferrite are more resistant to cracking than those solidified as primary austenite. In the second part of the paper solidification experiments have been performed at high cooling rates by using copper mould casting technique. By means of this technique, it has been possible to reproduce microstructures usually obtained in industrial processes such as welding. Finally, in the last part of the paper multicomponent diffusion theory has been used in order to treat the moving boundary problem in solidification and describe microsegregation phenomena.