Effect of Al Content in Low Carbon High Manganese TWIP Steel
Al addition in TWIP steel not only reduces the specific weight but also increases the stacking fault energy which strongly affects the deformation mechanisms. Hot rolled air cooled TWIP steel with low Al content (1.61 wt. %) reveals duplex microstructure comprising austenite with ferrite, whereas steel with higher content of Al (3.56 wt. %) reveals fully austenite microstructure. It is evident that nano-twins are formed within austenite grain after 50% cold deformation. TWIP steel with the duplex microstructure exhibits an excellent combination of strength and ductility. Hardness and tensile strength values of air cooled steel specimens increase with a concomitant lowering of total elongation with the application of cold deformation. However, steel with low Al content shows higher hardness and tensile strength along with lower elongation as compared to the TWIP steel having higher Al content.
Guojian Chen, Haider F. Abdul Amir, Puneet Tandon, Poi Sim Khiew
N. K. Tewary et al., "Effect of Al Content in Low Carbon High Manganese TWIP Steel", Key Engineering Materials, Vol. 706, pp. 16-22, 2016