Abstract
The objective of the present study is to investigate the effect of environmental relative humidity (RH) on the friction and wear characteristics of engineering metallic materials, especially. steels with different carbon content, under fretting conditions. Flat-against-ball type fretting wear tests for the steel disk in point contact with a bearing steel ball were conducted in moist air at an amplitude of relative slip (about 50μm). From the results, the mean coefficient of kinetic friction during the tests decreases with increasing RH for the steels except cast iron. The relative humidity (RH_<max>) at which maximum wear appears tends to move to higher RH levels with increasing carbon content of the steels. It is known that adhesive wear is predominant at RH_<max>. However, RH_<max> seems to decrease with increasing carbon content above 1%.
