Experimental analysis of transformation plasticity

Transformation plasticity is an irreversible strain observed when metallurgical transformation occurs under small external stress lower than the yield stress of the weaker phase. This paper is devoted to an experimental analysis of that phenomenon in ferrous alloys. The particular case of the steel which composes vessels in French nuclear reactors is considered. This steel is called 16 MND 5 and A 533 respectively in AFNOR and ASTM norms. The main results proposed in literature concerning transformation plasticity on this material were analyzed and perfectible aspects are pointed out. The results of several performed tests are analyzed. The transformation plasticity coefficient, the kinetics as well as the dependence on the norm and the direction of the applied stress are particularly studied. The experimental results are compared to the predictions of the main existing models.