Use of silicon calcium alloy
As calcium has strong affinity with oxygen, sulfur, hydrogen, nitrogen and carbon in molten steel, silicon calcium alloy is mainly used for deoxidizing, degassing and fixing sulfur in molten steel. The addition of calcium and silicon into molten steel produces a strong exothermic effect. Calcium turns into calcium vapor in molten steel, which has agitation effect on molten steel and is favorable for non-metallic inclusion to float on the surface. After deoxidizing, non-metallic inclusions with large particles and easy to float are produced, and the shape and properties of non-metallic inclusions are also changed. Therefore, silicon calcium alloy is used to produce clean steel with low oxygen and sulfur content and special performance steel with extremely low oxygen and sulfur content. The addition of silica calcium alloy can reduce the nodulation of aluminum final deoxidizing steel in ladle nozzle and the blockage of nozzle of continuous casting steel and ironmaking tunic. In the off-furnace refining technology of steel, silicon calcium powder or core wire is used to deoxidize and desulfurize, so that the content of oxygen and sulfur in steel can be reduced to a very low level. It can also control the form of sulfide in steel and improve the utilization rate of calcium. In the production of cast iron, in addition to deoxidation and purification, silicon calcium alloys also play the role of inoculation, contributing to the formation of fine or spherical graphite. The graphite distribution in grey cast iron is uniform and the tendency of white mouth is reduced. And can increase silicon, desulphurize, improve cast iron quality.
