Effects of aluminum on the microstructure and phase transformation of TRIP steels

In the present study, CMnSiAl transformation induced plasticity (TRIP) steels containing different amounts (0.04, 1.00, and 2.00 wt%) of Al were fabricated by thermo-mechanically processing. The influences of Al on the microstructure of cold-rolled TRIP steels was evaluated by various analytical techniques, including transmission electron microscopy, X-Ray diffractometry, electron back scattered diffraction and atom probe tomography (APT). The experimental results revealed that the TRIP steel containing 1.00 wt% Al showed the maximum volume fraction of retained austenite (RA) and the greatest elongation. However, the average carbon content of RA increased with the increase in Al content. Additionally, the distribution of alloying elements in the constituent phases was studied by APT.