Silicon-calcium alloy is a silicon-calcium alloy obtained from silica, lime and coke in a strong reducing atmosphere at 1500-1800 degrees.
Since calcium has a strong affinity with oxygen, sulfur, hydrogen, nitrogen and carbon in molten steel, silicon-calcium alloys are mainly used for deoxidation, degassing and fixation of sulfur in molten steel. Calcium silicon produces a strong exothermic effect when added to molten steel. Calcium turns into calcium vapor in molten steel, which has a stirring effect on molten steel and is beneficial to the floating of non-metallic inclusions. After the silicon-calcium alloy is deoxidized, non-metallic inclusions with larger 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, steel with low oxygen and sulfur content, and special-special-performance-performance-steel with extremely low oxygen and sulfur content. The addition of silicon-calcium alloy can eliminate the nodulation of the steel with aluminum as the final deoxidizer at the ladle nozzle, and the clogging of the nozzle of the tundish of continuous casting | ironmaking. In the refining technology outside the furnace of steel, silicon-calcium powder or core wire is used for deoxidation and desulfurization to reduce the content of oxygen and sulfur in steel 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 alloy also plays an inoculating role, which helps to form fine-grained or spherical graphite; makes the graphite in gray cast iron evenly distributed, reduces the whitening tendency; and can increase silicon and desulfurize , Improve cast iron quality.
