Variation in electric resistivity in metastable alloys during thermomechanical loading: Effects of temperature, elasticity, plasticity and phase transformation

摘要

301L metastable stainless steel is a ductile material in which there is strong coupling between plasticity and phase transformation, leading to strongly non-linear thermomechanical behaviour. To determine phase transformation kinetics, isothermal tensile tests at different temperatures were carried out and in situ voltage (electric resistance) was measured. We then chose an appropriate post-processing method based on observed voltage using strain and temperature. It was thus possible to determine the effect of temperature, elasticity, plasticity and phase transformation on the electric resistivity of the studied material. After identifying the effect of each strain mechanism, a volume phase fraction determination method based on electric resistivity variation was developed and used to determine the kinetics of phase transformation. Finally, we compared our results with those of two classic methods: the neutron diffraction method and the magnetic method.