Characterization of dry sliding wear resistance of laser surface hardened En 8 steel

Laser surface hardening, because of inherently high rates of heating and cooling associated with it, leads to the formation of inhomogeneous martensite in hypo-eutectoid steels. This is in contrast to conventional transformation hardening where sufficiently long soaking period above Ac3 temperature ensures homogenization of carbon in the resultant martensite. The present study aimed at characterization of dry sliding wear resistance of laser surface hardened En 8 steel specimens and its comparison with those of conventionally hardened and quenched and tempered. The results of the study demonstrated that wear rate is critically dependent on the presence of oxide film on the surface which, in turn, is significantly influenced by testing parameters as well as by dynamic conditions during the course of testing. Under the experimental conditions of dry sliding wear, used in this work, laser surface hardened En 8 steel specimens exhibited superior wear resistance than conventionally hardened specimens. Wear resistance of laser surface hardened specimens was largely comparable to that of quenched and tempered specimens.