Influence of pre-strain on the wear resistance of a plain carbon steel

Dry sliding wear behaviour of a plain carbon steel in different pre-strained conditions was examined in the severe wear regime using a pin-on-disk wear testing machine. The severe wear regime was ascertained by determining wear rates of the unstrained material at different loads. The primary experiments were supplemented by microstructural characterization, hardness assessment of specimens before and after wear tests, determination of tensile properties of the pre-strained specimens and SEM examination of the worn-out surfaces and subsurfaces. The results indicate that the wear rate of the specimens first increases up to 15% pre-strain and then decreases, while the hardness and tensile strength of the specimens monotonically increases with increased pre-strain. The mechanism of wear is observed to be subsurface cracking and delamination aided by oxidative wear. The imposed pre-strain on a specimen is considered to aggravate the nucleation of voids and microcracks resulting in degradation of wear resistance of the pre-strained specimens. The results infer that wear rates of pre-strained materials are governed by ductility or toughness apart from hardness and strength.