Abstract
Wear experiments of a carbon steel in wet air and in dry air were conducted by using a pin-on-disk wear test rig to obtain the relationship between the wear rate and contact load. The severe and mild worn-surfaces of pin specimens were observed with a SEM before and after etching. A digital measurement system including a surface profilometer and a personal computer made it possible to analyze the three-dimensional topographies of pin specimens in severe and mild wear regimes, especially to investigate the shape of each asperity by dividing the worn surface into small areas. These experimental results were useful in evaluating the condition for T1-transition from severe to mild wear in wet air. In the T1-transition and mild wear regimes, the readhesion of wear debris to the lower part of the worn surface resulted in the generation of large flat-surface. One of the most important conditions for the T1-transition was that the mean contact pressure at the flat-surfaces fell rapidly to the contact pressure in the mild wear regime owing to the wear of asperities in the severe wear regime.
