With the increasing quality requirements for cast steel, the use of aluminum for deoxidation of some high-grade castings cannot meet the requirements. Therefore, the use of aluminum and calcium composite deoxidation has received extensive attention.
In the final deoxidation, the combination of aluminum and calcium can not only further reduce the oxygen content in the steel, but also improve non-metallic impurities.
Because the density of calcium is only 1/5 of that of steel, the boiling point is 1492℃, which is lower than the temperature of molten steel, and its activity is very strong, so it is difficult to accurately control it when used in steelmaking. This restriction has restricted the popularization and application of calcium in cast steel.
In the past 20 years, the understanding of the role of calcium in steel has been deepened, and the application process has gradually matured. Now, it has been widely used.
