Interfacial Reaction Between Molten Sn and Plasma Nitrided Stainless Steel

Erosion behavior of plasma nitrided stainless steel by molten Sn was examined. To investigate the erosion behavior, the interfacial reaction was investigated at the temperature ranging from 350 to 450°C using plasma nitrided SUS304 and SUS316 stainless steel which sandwich pure Sn foil. As the results, it was found that the surface area of the nitrided layer is peeled and subsequently FeSn₂ phases form in the reaction interface. FeSn₂ phases grow toward molten Sn and Sn diffuses into the nitrided layer. Moreover, Ni₃Sn₄ phases form and grow in molten Sn. Apparent activation energies of the Sn diffusion into the nitrided layer were estimated to be 153 kJ/mol and 133 kJ/mol for plasma nitrided SUS304 and SUS316, respectively.