Microstructure and mechanical behaviors of GPa-grade TRIP steels enabled by hot-rolling processes

This work clarifies the effects of hot-rolling processes on microstructure and mechanical properties in Fe-0.21C-2.04Mn-1.04Si-1.10Al-0.064Nb-0.2Mo (in wt.%) alloy. Two strong and ductile transformation-induced plasticity steels with distinguishable stress-strain behaviors were developed. Nano/microstructures, strengthening mechanisms, and behaviors of transformation-induced plasticity in two steels were elucidated based on investigations of electron backscattering diffraction, transmission electron microscopy, and X-ray diffraction. The metallurgical principles can be applied to fabricate new transformation-induced plasticity steels directly by hot-rolling processes.