Inclusion Control of 15-5 PH High-strength Stainless Steel through Aluminum Deoxidation

15-5PH high-strength stainless steel is an important alloy used for numerous critical components. Ultra-low oxygen content and inclusion control have become urgent problems that need to be addressed the broad application of this steel. In study, we investigate thermodynamic equilibrium Al–O morphology understand basic mechanism behind results obtained after commercial production alloy. The deoxidation behavior depends on dissolved Al ([Al%]). When [Al%] <0.001%, mixed Al–Si occurs product Al2O3–SiO2–MnO–CrOx. ≥0.001%, simple dominant MgO·Al2O3. formation Al2O3–SiO2–MnO–CrOx, low melting point inclusions, a MgO·Al2O3 interface layer reduces activity Al2O3, which why calculated are higher than experimental results. measured demonstrate relatively good agreement with values. This proved phases formed crucible surfaces were in O contents molten steels holding 120 min.