Silicon manganese (SiMn) also known as silicomanganese, a ferroalloy with high contents of manganese and silicon, is made by heating a mixture of the oxides manganese oxide (MnO2), silicon dioxide (SiO2), and iron oxide (Fe2O3), with carbon in a furnace. They undergo a thermal decomposition reaction. It is used as a deoxidizer and an alloying element in steel. Silicon increases the strength without a serious loss of ductility. It also adds scale resistance. These steels are generally heat treated to specific properties. The standard grade silicon manganese contains 14 to 16% of silicon, 65 to 68% of manganese and 2% of carbon. The low carbon grade SiMn has carbon levels from 0.05 to 0.10%