The deformation behavior of TRIP steel at the macroscopic level is experimentally investigated. It has been established that the deformation-induced austenite → martensite phase transformation is developed by shaping localized deformation fronts and can be described in terms of the propagation of the Luders and Portevin–Le Chatelier bands; therefore, the theory of autowave localized plasticity is applicable to them. On the elastoplastic transition, the transformation is realized in the form of auto-switching waves, which originate, propagate, and annihilate. With further loading of the zone of origin of auto-switching waves, they become sources of excitation autowaves.