Investigation of surface modifications for combating the molten aluminum corrosion of AISI H13 steel

In this study, we performed three surface modifications for AISI H13 steel to study their protective effects in 1023 K molten aluminum. Results showed that air oxidation can produce a thin film of Fe2O3 and little FeO, and the liquid-nitriding formed a surface of iron nitrides and oxides (Fe2O3 + Fe3O4). While liquid-nitriding with post-oxidation can form a surface of Fe3O4 and little Fe2O3 by oxidizing the nitrides into Fe3O4 on the liquid-nitriding samples. The Fe3O4 has low wettability and good chemical stability against molten aluminum, thus the corrosion behaviors of molten aluminum to the samples change from dissolution to oxidation.