Effects of Alloying Process on Inclusions in Fe-9Cr Alloy Reinforced with Y2O3 Nanoparticles

The effects of the alloying sequence and refining time on the inclusions in Fe–9Cr alloy reinforced with Y2O3 nanoparticles were investigated. The size and number of inclusions in the alloys were determined via optical microscopy, and their morphology and composition were determined via scanning electron microscopy. The Y2O3 mainly acted as a nucleating agent in the Si–Mn+Y2O3+Ti alloying process, promoting the precipitation of other oxides, which was beneficial for the formation of Y–Ti–O particles. In contrast, no Y–Ti inclusions were formed when the Si–Mn+Ti+Y2O3 alloying process was employed. In addition, the inclusions in the alloy tended to stabilize after refinement for 5–10 min. This study offers a general pathway for the manufacture of oxide dispersion strengthened steel via a smelting process.