Decomposition of retained austenite during coiling process of hot rolled TRIP-aided steels

Abstract Laboratory simulation of hot rolling and coiling processes and in situ heating observations have been carried out in order to evaluate the decomposition behavior of the residual austenite in hot rolled 0.2C–1.5Mn–2Si transformation induced plasticity (TRIP)-aided steels. Residual austenite was thermally stable up to 350 °C and then decomposed into various phases depending on the coiling temperatures: carbide-free bainitic ferrite, ferrite associated with cementite and pearlite. The difference of these decomposition behaviors will be discussed in terms of the variation of carbon concentration and thermal stability of the residual austenite depending on coiling temperatures and holding times.