TRIBOCORROSION PHENOMENA IN CO- AND FE-BASED HARDFACING ALLOYS EVALUATED USING PIN-IN-ON-DISC WEAR TESTS IN A SIMULATED PWR ENVIRONMENT

摘要

The like-on-like sliding wear behavior of hardfacingalloys Tristelle 5183, RR2450, Stellite 6 and Stellite 3 wasinvestigated at 20°C and 250°C using a pin-on-discapparatus in a simulated PWR environment. Stellite 3wears considerably less than Stellite 6 at 20 and 250°Cbut both exhibit an increase in wear with increasingtemperature; the total mass loss increases approximately20 times. At 20°C, the iron-based alloys, especially 5183,wear more than the Stellite alloys but both iron-basedalloys show a smaller increase in wear with increasingtemperature. At 250°C, Stellite 6, 5183 and RR2450 havestatistically similar mass losses post wear testing.Tristelle 5183 does not exhibit a significant increase inwear with respect to increasing temperature whereas theincrease in wear for RR2450 is approximately four-fold.In the Stellite alloys, it is the increasing severity of atribocorrosion mechanism that principally dictates theincrease in rate of material removal with respect toincreasing temperature. In Tristelle 5183, plasticitydominated wear occurs at 20°C but at 250°C theformation of an additional oxide-based tribofilmcounteracts other high temperature wear mechanisms. Asimilar mechanism is also believed to operate in RR2450.