Tribocorrosion resistance of plasma carburizing stainless steel AISI 316L and AISI 304 with the STCzelle

Tribocorrosion has been studied for many years by electrochemists as well as by tribologists, using different approaches. Electrochemists and corrosion scientists have been interested in the study of kinetics of repassivation of metal surfaces activated by mechanical process. On the other hand, tribologists have been interested in how surface oxidation during rubbing affects the rate of mechanical wear. More recently the mutual dependence of mechanical and electrochemical mechanisms has found increased attention. Electrochemical methods are particularly well suited for this purpose, because they provided an accelerated corrosive effect simulation though the potentials control and a current density response. This work is about a tribocorrosion resistance of Plasma Carburized Stainless Steel AISI 316L and AISI 304 with the STCzelle (interface cell). The samples were treated at two different temperatures (375°C and 450°C) during 8hs, using a CH4/H2 gas mixture. The wear tests were carrid out in a tribometer with a linear sliding. The electrochemical parameters were controlled by a Galvanostat/Potentiostat EGE&G PAR 273 A. The Interface cell has a three electrodes configuration: work electrode in the horizontal position, SSC reference electrode with a Lugging capillary and Pt counter-electrode. The tribocorrosion system was made in Fraunhofer IPA (Germany). The samples were analysed in Ringer's solution (pH 7,3 and 37°C), under polarization (+250 mV) with an applied normal force of 8N. Results show that surface hardness and tribocorrosion resistance were improved when the samples were plasma carburized at 375°C.