Wear mechanisms in unlubricated chains

This paper describes the results of wear tests on unlubricated articulating chains. Experiments with a martensitic stainless steel chain showed that under certain conditions of load, motion and environment, unexpected wear patterns could develop, with high and low wear alternately on adjacent pins and bushes. Examination of specimens tested in different atmospheres showed that the same fundamental wear mode, severe adhesive wear, was involved throughout. The variation in wear rate, both environmental and geometric, was caused by wear debris acting as a solid lubricant of variable efficacy. A second, surface hardened chain material was also tested. Whilst this wore relatively evenly at a very low rate indeed, it also suffered from progressive surface spalling and this feature would probably be life-limiting