The Influence of Precipitation, High Levels of Al, Si, P and a Small B Addition on the Hot Ductility of TWIP and TRIP Assisted Steels: A Critical Review

The hot ductility of Transformation Induced Plasticity (TRIP) and Twinning (TWIP) steels is reviewed, concentrating on the likelihood cracking occurring continuous casting during straightening operation. In this review, influence high levels Al, Si, P, Mn C their will be discussed as well important role B can play in improving ductility. Of these elements, Al has worst but a addition often needed both TWIP TRIP steels. AlN precipitates are formed thin coatings covering austenite grain surfaces favouring intergranular failure making them difficult to cast without cracks forming. Furthermore, with un-recrystallised austenite, which state when straightening, suffers from excessive boundary sliding, so that decreases increasing temperature, resulting RA value being below avoid straightening. Fortunately, used remedy deleterious AlN. precipitation hardeners (Nb, V Ti based) strengthening room temperature yield strength also discussed.