Function in Molten Steel
Calcium silicon alloy is mainly used for deoxidizing, degassing, and fixing sulfur in molten steel because of its strong affinity with oxygen, sulfur, hydrogen, nitrogen, and carbon in molten steel. It produces a strong exothermic effect when added to molten steel. Calcium turns into calcium vapor in the molten steel, which has a stirring effect and is favorable for the floating of non-metallic inclusions.
Inclusion Modification
After deoxidation with calcium silicon alloy, non-metallic inclusions with large particles that are easy to float are produced, and the shape and properties of the inclusions are changed. Therefore, calcium silicon alloy is used to produce clean steel, high-quality steel with low oxygen and sulfur content, and special performance steel with extremely low oxygen and sulfur content. Adding calcium-silicon alloy can eliminate the problems of ladle nozzle clogging in steel with aluminum as the final deoxidizer and the blockage of the intermediate tank nozzle in continuous casting.
Out-of-Furnace Refining
In the technique of steel refining outside the furnace, calcium-silicon powder or cored wire is used for deoxidation and desulfurization, reducing the oxygen and sulfur content in the steel to a very low level. It can also control the form of the sulfides in the steel and improve the utilization rate of calcium.
Use in Cast Iron
In the production of cast iron, in addition to its deoxidizing and purifying effects, the calcium-silicon alloy also acts as an inoculant, helping to form fine-grained or spherical graphite. This results in a more even distribution of graphite in gray cast iron and reduces the tendency to white cast iron. It also increases the silicon content and removes sulfur, improving the quality of the cast iron.
Frequently Asked Questions
What does calcium silicon alloy do in steel? It deoxidizes, degasses, and fixes sulfur, and modifies inclusions to produce cleaner steel.
How does calcium silicon solve nozzle clogging? It modifies alumina-based inclusions so they float out instead of clogging ladle and tundish nozzles.
What is calcium silicon used for in cast iron? s an inoculant that promotes fine-grained or spherical graphite and reduces white cast iron tendency.
How is calcium silicon added during out-of-furnace refining? s powder or cored wire, which deoxidizes and desulfurizes the steel to very low oxygen and sulfur levels while controlling inclusion form.
Why do calcium-silicon inclusions float out more easily? Deoxidation with calcium silicon forms larger non-metallic inclusions with modified shape and properties, so they float out of the melt instead of remaining in the steel.
