Silicomanganese (Si-Mn):
Silicomanganese is used as a more effective deoxidizing agent than high carbon ferromanganese in the production of various types of steels. It is also used as feed stock to produce refined alloys like medium and low carbon ferromanganese. There is an increase in usage of silicomanganese in the steel making. Silicomanganese is preferred in many of the mini steel mills because it contains the right proportion of manganese and silicon and low carbon. As per the BIS specifications (IS: 1470-1990) the silicomanganese contains 14-28% Si, 50-74% Mn and 1to 2.5% C.
The presence of silicon has the added advantage of producing cleaner steel and also has the property of reducing the time required from the stage of alloy addition to the pouring of ingot. Besides, it gives better mechanical properties due to change in morphology of deoxidation products in regular round shape, and consequently the non-metallic inclusions are brought down in finished products.