Carbon Solubility and Phase Composition of Silicomanganese

This paper examines silicomanganese produced in the electric ferroalloy furnaces at Tasmanian Electrometallurgical Company (TEMCO). Its carbon solubility and the phase composition were determined. Silicon content is the major factor affecting carbon concentration. Temperature also plays an important role in the carbon concentration. Silicomanganese consists of three phases: the silicides (Mn,Fe)5Si3 with approximately 0.7 wt% dissolved carbon and (Mn,Fe)3Si with a carbon content of 0 ‐ 0.6 wt%, and carbide (Mn,Fe)17Si4C3 with 3.3 wt% C. The fraction of carbide phase increased directly with increasing total carbon in the alloy. Silicon carbide was not detected. Reasonable estimates of carbon content are possible using the carbon‐silicon equilibrium relationship to the SiMn production process of TEMCO.