Influence of environment on the unlubricated wear of 316 stainless steel at room temperature

Abstract

The wear of a type 316 austenitic stainless steel has been studied in a variety of gaseous atmospheres at constant load and slidind speed under reciprocating conditions. The environments reported include air, CO 2, argon and partial vacuum. The wear debris in all cases was essentially metallic and its rate of production per unit length was constant with sliding distance. On this evidence the wear process was classified as being of the severe type. There was, however, a wide range of specific wear rates which varied by a factor 30 extending from 1 × 10 −13 m 3/N m in air to 3 × 10 −15 m 3/N m in argon, decreasing with decreasing oxygen partial pressure. It is thought that the wear process in all the atmospheres examined was basically the same, being one of prow formation with the subsequent breakdown of these features to wear particles. The initial stage in prow growth is the formation of transfer elements or platelets by asperity interactions and their accumulation to form plateaux. There was a correlation between wear rate and platelet size, the wear rate decreasing with decreasing platelet size. The prow formation stage is considered to be the rate limiting step in the severe wear of ductile materials, but the influence of oxygen partial pressure on transfer element size needs further investigation.