Corrosion of martensitic and austenitic steels in liquid gallium

The compatibility of 1.4914 martensitic steel and 316 L austenitic stainless steel has been studied in the presence of static liquid gallium. It was shown that the materials are severely attacked by the liquid metal. The corrosion is characterized by the formation of a reaction layer identified as FeGa₃. Depending on the steel, the growth kinetics and the morphology of the layer are found to be different. In the case of 1.4914 steel, the growth law is linear, which implies an interface controlled regime. Moreover, the layer formed from an initially rectangular substrate exhibits a typical cruciform pattern. In the case of 316 L steel, a parabolic growth is found after a transient period, indicating a process mainly controlled by diffusion. Contrary to the martensitic steel, the morphology of the layer occurring during the solid-liquid interaction leads to complete coverage of the 316 L substrate, with rounded edges.