Subsurface characteristics of an abraded Fe-0.4 wt%C pearlitic steel: A nanoindentation study

The present investigation of a unidirectionally abraded pearlitic (0.4 wt%C) steel and the steel with vanadium addition (0.1 wt%V) elucidates the work hardening and the reorientation near the surface layer caused by abrasion, particularly its relation to the wear behavior. The abraded surfaces were examined with a nanoindentation apparatus to evaluate the variation of nanohardness and elastic modulus with depth below sliding contact on a nanometer scale. It has been found that the wear rate of each specimen was almost equal, although the nanohardness of the abraded surface of the vanadium addition steel was lower than that of the vanadium free one. The elastic modulus of the vanadium free steel increased with decreasing the indentation depth below the abraded surface to about 1.3 times the original value (∼200 GPa), while the vanadium addition steel was constant. The varying nature of influence of interlamellar spacing and the vanadium addition on the wear response of the pearlitic steel has been discussed in terms of the ratio between hardness and elastic modulus of the abraded surface which corresponds to a plasticity factor.