Microstructure evolution of medium‑manganese Al-alloyed steel manufactured by double-step intercritical annealing: Effects of heating and cooling rates

A novel double-step intercritical annealing (DSIA) process was conducted on Fe-0.16C-4.7Mn-1.6Al-0.2Si transformation induced plasticity (TRIP) steel. In a present study, an effect of different heating and cooling rates applied to the second (IA) step microstructure studied in detail by using scanning electron microscopy (SEM), backscatter diffraction (EBSD) transmission (TEM) techniques. The quantitative analysis retained austenite fractions for particular heat treatment variants carried out via X-ray (XRD). formation complex microstructures containing small fraction ferrite, two types martensite observed regardless rates. It found that soft ferrite can be replaced through incomplete stabilization with C Mn during short step. rate influences significantly kinetics Low ensure more time homogenization improving its thermal stability. Thus, best balance combination homogenous morphology noted specimen heated at 3 °C/s, which lowest one reported experiment.