Abstract Developments in third-generation advanced high-strength steels (AHSS) have produced stronger and more formable steels for the automotive industry by controlling chemical composition and mechanical processing. Cracking during cooling after continuous casting has been a prominent problem for these steels and is believed to be influenced by the steel microstructures. In this study, the effects of chemical composition on the mechanical properties are investigated for as-cast steels by performing mechanical tests on steels containing 0.2 wt pct C and 3 wt pct Mn with varying Si and Al concentrations up to 3 wt pct. Tensile tests were performed to measure strength and ductility at temperatures from 200 °C to 600 °C. Si-alloyed steels have the highest yield strength, while combined silicon- and aluminum-alloyed steels have higher ductility. Fracture surfaces were examined and crack paths were found not to propagate along the ferrite in the microstructure.
Ngo et al. (Thu,) studied this question.