Cast Medium-Manganese FeMnAlSiC Steel

Certain medium-manganese (6-12 wt% Mn) steels can be heat-treated to produce single-phase (austenite) or multi-phase (ferrite, austenite, bainite, martensite, and/or iron carbide) microstructures. With the proper amount of silicon and aluminum, both transformation-induced plasticity (TRIP) and/or twinning-induced plasticity (TWIP) can be the active deformation mechanism. In this study, two steel heats with compositions of Fe-7.53Mn-2.01Al-1.94Si-0.74C and Fe-7.71Mn-1.57Al-1.51Si-0.50C were investigated. The lower-carbon steel had a wider heat treating range but did not achieve as high of a hardness as the higher-carbon steel. Multi-phase microstructures were produced in both of these steels, and the multi-phase microstructures had higher yield strength compared to single-phase (austenite) microstructures. A high iron and manganese content skull adhered to the sides of the furnace after induction melting. This skull was difficult to remove from the furnace lining.

Automated summary

Certain medium-manganese steels with proper silicon and aluminum content can be heat-treated to produce different microstructures, such as single-phase or multi-phase. The study investigated two steel heats with different carbon contents and found that the multi-phase microstructures had higher yield strength compared to single-phase microstructures. Additionally, a hard skull of high iron and manganese content adhered to the furnace lining after induction melting, which was difficult to remove.