Influence of Ce on Characteristics of Inclusions and Microstructure of Pure Iron

Abstract

The experiments on adding Ce, Mn and S to molten iron have been carried out by means of the electric furnace, and the concentration of oxygen, the evolution of inclusions and microstructures of samples are analyzed, indicating that the concentration of dissolved oxygen decreases greatly after adding Ce. The calculated thermodynamics results at 1273 K performed on Factsage show that Ce 2O 2S and CeAlO 2 are formed with the increase of Ce content for w(Ce) > 0.0002 and w(S) < 0.0001, while three cerium sulphides (CeS, Ce 3S 4 and Ce 2S 3, in sequence), MnS and Ce 2O 2S are formed with the increase of S content and the decrease of Ce content for w(Ce) > 0. 0002 and w(S) > 0.0001. These results are consistent with the SEM observations. Finally, some possible reasons are given to explain the formation of intragranular ferrite in the pure iron.