Analysis of the Fe–Ce–O–C–M phase diagrams (M = Ca, Mg, Al, Si) by constructing a component-solubility surface

TLDR: In this paper, the ternary phase diagrams of Ce2O3-and CeO2-containing oxide systems are analyzed to find the oxide compounds that form during steel deoxidizing with cerium and with Cerium together with aluminum, calcium, magnesium, or silicon.

Abstract: Analysis of the ternary phase diagrams of Ce2O3- and CeO2-containing oxide systems allowed us to find the oxide compounds that form during steel deoxidizing with cerium and with cerium together with aluminum, calcium, magnesium, or silicon. The temperature dependences of the equilibrium constants of formation of Ce2O3 oxides and Ce2O3 · Al2O3, Ce2O3 · 11Al2O3, Ce2O3 · 2SiO2, 7Ce2O3 · 9SiO2 and Ce2O3 · SiO2 compounds are found. Surfaces for the component solubility in metallic melts Fe–Al–Ce–O–C, Fe- Ca–Ce–O–C, Fe–Mg–Ce–O–C, and Fe–Si–Ce–O–C are constructed. Nonmetallic inclusions that form in the course of experimental melts of St20 steel after its deoxidizing with silicocalcium and rare-earth metal (REM)-containing master alloys in a ladle furnace after degassing are studied. Phase inhomogeneity of the inclusions is found. As a rule, they consist of phases classified into the following three groups: oxide–sulfide, sulfide–oxide, and multiphase oxide–sulfide melt. Calcium aluminates are found to be components of complex sulfide-oxide noncorrosive inclusions.