A simple identification of transformation plastic behaviour and some data for heat treating materials

Transformation plasticity is known to play an important role in the course of heat treatment processes, and so affects the results of heat treatment simulations. For carrying out proper simulations, material data for this phenomenon (practically, the transformation plasticity coefficient) are required. In this paper, the authors introduce a new method by use of the four-point bending system of a beam to identify the transformation plasticity coefficient, taking advantage of its easiness and high accuracy compared with other conventional methods like tension test, etc. When the temperature reaches the transformation starting point, a tremendously large deflection takes place due to the effect of transformation plasticity, which gives fundamental data to identify the value of the coefficient. Some data measured for several heat treating steels under different applied stress are presented, which are compared with data taken by other methods in references.