Kinetics of Lüders and Portevin–Le chatelier bands in steel with strain-induced phase transformation

Abstract

The formation and propagation of strain-induced phase transformation bands were studied in TRIP steels obtained under various thermomechanical processing conditions. The phase transformation during the pseudo-plateau stage is shown to occur as switching autowaves that propagate in the form of the Luders bands. After the annihilation of switching authowaves in the austenite state, the strain hardening is manifested by excitation autowaves being the Portevin–Le Chatelier fronts (PLC). Hot rolling to 63% reduction allows one to avoid the jerky flow stage and the PLC bands. The generation and propagation of martensite transformation bands are evident from the appropriate phase distribution collected via the magnetic measurements.