Temperature dependence of plastic deformation mechanisms in a modified transformation-twinning induced plasticity steel

The plastic deformation behavior of a modified transformation-twinning induced plasticity steel is investigated in a wide range of temperature from 25 to 1000 °C through compression testing. The main emphasis is on different plastic deformation mechanisms involved. The results show that the flow stress is rigorously dependent on deformation temperature and this behavior is classified in three characteristic regions. The strain-induced martensite is detected as the chief plastic deformation mechanism from 25 °C to a comparably high temperature of 200 °C. The activation of deformation twinning as the second deformation mechanism starts with an ascending trend from 200 to 300 °C. This is followed by a descending trend in the range of 300–500 °C. In addition, the remarkable presence of deformation twins at temperatures above 200 °C has led to the formation of a new fine grain structure. The restoration processes as the third deformation mechanism are detected in the range of 700 to 1000 °C. The dynamic recrystallization is the most important softening mechanism for the experimental steel during hot compression from 900 to 1000 °C.