Thermodynamics of Reaction between Trace Amount of Al and Inclusion in Mn-Si Killed Steel

To control the composition control of inclusion in Mn-Si killed steel, elucidation of the thermodynamics of the reaction between trace amounts of Al and manganese-silicate inclusions is very important. SIMS (Secondary Ion Mass Spectrometry) was adopted for the microanalysis of dissolved Al in the steel. Based on the results of fundamental experiments, the thermodynamic behavior of the slag-metal-inclusion reaction was discussed, using the analytical value obtained by SIMS. Trace amounts of dissolved Al in the steel could be measured using SIMS without influencing the inclusion. The inclusion compositions in the molten steel were predicted by trace amounts of dissolved Al in Si-Mn killed steel.