Equilibrium between Ti and O in Molten Fe–Ni, Fe–Cr and Fe–Cr–Ni Alloys Equilibrated with ‘Ti3O5’ Solid Solution

Abstract

The Ti deoxidation equilibrium of Fe–Ni, Fe–Cr and Fe–Cr–Ni alloys saturated with ‘Ti3O5’ and Ti2O3 phase was clarified in previous researches. Solubility of Fe, Cr and/or Ni oxides in ‘Ti3O5’ phase equilibrated with liquid Fe–Ni, Fe–Cr and Fe–Cr–Ni alloys at 1823 K to 1923 K were measured by SEM–EDS. It was confirmed that the solubility of Fe, Cr and/or Ni oxide in ‘Ti3O5’ phase at low Ti content increase with decrease of Ti content in alloys. Titanium content that dissolution of Fe, Cr and/or Ni oxide into ‘Ti3O5’ phase becomes apparent increases with increase of Cr and/or Ni content of the alloys. The activity of Ti deoxidation product, ‘Ti3O5’ phase, equilibrated with Fe–Ni, Fe–Cr and Fe–Cr–Ni alloys was also evaluated by Redlich-Kister type polynomial. Equilibrium between Ti and O at low Ti content of those alloys was analyzed using the activity of ‘Ti3O5’ phase.