Samples from calcium-treated liquid steel at Visakhapatnam Steel Plant (VSP), Visakhapatnam are studied under scanning electron microscope to understand the inclusion evolution under various operating parameters. The compositions of inclusions are plotted in ternary Ca–Al–S diagram to evaluate the efficiency of inclusion modification and stable casting operation. Process parameters such as amount of calcium addition, bath superheat, and the speed of wire injection are studied for calcium treatment of steel. Both CaFe and CaSi addition are studied, and calcium recovery for CaFe addition is always found to be less than CaSi addition for the same operating conditions. For CaSi addition, the recommended ranges in terms of bath superheat, wire speed, and the amount of calcium addition are identified for the operating conditions studied for VSP, Visakhapatnam.
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