Application of silicon manganese alloy in steelmaking
Silicon manganese alloy is an alloy composed of manganese, silicon, iron and a small amount of carbon and other elements. It is a kind of iron alloy with wide use and large yield. The consumption of silicon manganese accounts for the second place of ferroalloy products in electric furnace.
Silicon manganese alloy is mainly used as the intermediate material of deoxidizer and alloy agent in iron and steel production as well as the main raw material of low carbon ferromanganese production. Silicon and manganese in silicon-manganese alloy have a strong affinity with oxygen. When silicon manganese alloy is used in steelmaking, the resulting deoxidation products MnSiO3 and MnSiO4 melt at 1270℃ and 1327℃ respectively, with the advantages of low melting point, large particles, easy to float, good deoxidation effect and so on. Under the same conditions, the burning loss rate of manganese or silicon deoxidization is 46% and 37% respectively, while that of silicon manganese alloy deoxidization is 29%.
Therefore, silicon manganese has been widely used in steelmaking, its yield growth rate is higher than the average growth rate of ferroalloy, and it has become an indispensable composite deoxidizer and alloy additive in steel industry. Silicon-manganese alloy with carbon content below 1.9% is also used for the production of medium and low carbon ferromanganese and electrosilicon-thermal manganese metal semi-finished products.
In ferroalloy production enterprises, usually the silicon-manganese alloy used in steelmaking is called commodity silicon-manganese alloy, the silicon-manganese alloy used in smelting low carbon iron is called self-use silicon-manganese alloy, and the silicon-manganese alloy used in smelting metal is called high-silicon silicon-manganese alloy. Manganese can combine with silicon to form silicide MnSiO3, MnSiO and MnSiO3. As can be seen from the silicon-manganese state diagram, the stable silicide is MnSi. The negative value of the free energy of silicide formation of manganese is much larger than the negative value of the free energy of carbide production of manganese. The higher the silicon content in the silicon-manganese alloy, the lower the carbon content.
