AISI 316L Stainless Steel Substrates Research Articles

Temperature-dependent surface modifications of AISI 316L and AISI 440C stainless steel substrates

Using X-ray photoelectron spectroscopy (XPS) we have analyzed the surface composition of austenitic AISI 316L and martensitic AISI 440C stainless steels after 1 h annealing in high vacuum at temperatures between 25 and 1000°C. On both steels we have observed, in the temperature range between 350 and 850°C, strong chromium (Cr), manganese (Mn) and silicon (Si) diffusion from the bulk to the surface. The composition of the forming surface layer (thickness about 50 Å) was strongly temperature-dependent and completely different from the bulk. We conclude that the well known difference in the quality of the adhesion of hard PVD coatings on stainless steels can be related to the surface composition of the steel substrate.