Heat and thermochemical treatments of austenitic steels and their influence on corrosion resistance

Abstract

Abstract A structure with good corrosion resistance mainly characterized by a largely austenitic metal mass, is contained in chromium and nickel high alloyed steels. Surface and heat treatments can possibly influence this quality to a great extent. In the paper, steel samples with high content of chromium and nickel were subjected to several different technologies, from which some are using temperature. Heat and thermochemical treatments of austenitic steels and their influence on corrosion resistance include a treatments’ spectrum of hardening by putting into solutions, cold plastic deformation, nitriding, carbonitriding, etc., effectuated on 316L steel samples, with the working parameters being indicated in the paper for each individual process. The changes made in the mechanical properties and structure were studied for each lot of specimens. Taking into account that for parts of this category of steel it is required a good resistance to oxidation and corrosion, besides a certain ensemble of mechanical characteristics, this was also studied. In order to determine the corrosion resistance, the most reliable approach is to use a potentiostatic technique to determine a series of characteristic parameters. They emphasize significant differences in treatments occurred. Concluding, surface treatments generally lead to a decrease in corrosion resistance