Improvement of high temperature oxidation resistance of AISI 316L stainless steel by incorporation of Ce-La elements using intense pulsed plasma beams

摘要

It is well documented that adding some active elements (such as Y, Ce, La, Er, others) to austenitic stainless steels helps to improve their high temperature oxidation resistance. In the present work we report preliminary results of incorporation of Ce and La into austenitic stainless steel AISI 316L using a new approach based on high intensity pulsed plasma beams. The characteristic feature of this approach relies upon the fact that incorporation of Ce-La occurs in the transiently melted near-surface layer of the substrate. Improving the near surface layer properties was connected with two facts: (i) material melting and cooling with very high rate and (ii) incorporation Ce-La to the molten phase. Modified samples were oxidized at 1000. °C for 80 h in air at atmospheric pressure. The obtained effects were similar to those observed in chromia-forming alloys doped by other conventional surface treatment techniques: oxide scales formed on the treated samples were more fine-grained, compact and adhered better than those formed on the un-treated samples, whereas the protective layer was produced closer to the surface.