This paper investigates the effect of electron beam (EB) surface hardening on the abrasive wear property of AISI 4340 steel. The heat treatment conditions were varied so that the influence of microstructures on the wear resistance could be evaluated. A dry sand/rubber wheel abrasion test was selected to evaluate the high stress wear properties. The results show that the weight loss decreases with increasing hardness of surface layer or base material. The EB surface hardening can improve the abrasive wear resistance by about 10%. The best heat treatment process for AISI 4340 steel against abrasive wear is oil quenching from 840-degrees-C, tempering at 370-degrees-C, then EB surface hardening under heat input of 135-150 J mm-1. The width and depth of the wear tracks are reduced after the EB surface hardening treatment.
