Effect of testing temperature and strain rate on the transformation behaviour of retained austenite in low-alloyed multiphase steel

The influence of temperature and strain rate on the evolution of the retained austenite content during plastic straining has been studied by tensile tests performed at 4 × 10−4, 10−2 and 0.4 s−1 between −100 and 450 °C. Up to 150 °C, the austenitic volume fraction mechanically transformed decreases with increasing testing temperature being almost independent of strain rate. In contrast, above 150 °C the martensite transformation depends on testing temperature and strain rate since it is related to the ability of carbon atoms for pinning dislocations.