Modeling and Experimental Investigation of Fracture Behavior of Hot-Rolled Hypereutectoid Si-Mn TRIP Steel: Heat-Treatment Effect

This study aimed to investigate the fracture and hardening behaviors of transformation induced plasticity (TRIP) steel at different heat-treatments using the uniaxial tensile test and the necking correction method to study the effects of various heat treating procedures and strain rates in the microstructural evaluation, mechanical properties, and fracture behavior of the investigated steel. The uniaxial tensile tests were performed on samples heat-treated through different procedures and strain rates in the range of 0.005–5 s⁻¹. It was observed that the strain rate slightly affects the formability of TRIP steel in different heat-treatment procedures. The obtained results showed that the H3 sample in which the samples austenitized at 900 °C for 22 min then soaked at 400 °C for 1 h and finally quenched in oil at 50 °C and cooling at ambient temperature had the highest strain fracture. The nucleation and growth of voids, as well as the dynamic equilibrium between strain hardening and recovery, were reasons for fracture strain increment from 0.005 to 0.1. However, fracture strain decreased at the strain rate of 0.1–5 s⁻¹ due to the decrease of ductility. Also, TRIP steel characterizations were used for modeling the displacement and stress of the anti-roll bar by ANSYS 19.2 parametric language and Solid-Works. The displacement and stress results of TRIP steel were compared to SAE Class 550 and Class 700 grades of steel.