Effect of frictional treatment on the microstructure and surface properties of low-carbon steel

Abstract

The microstructure of annealed low-carbon (0.17 wt% C) steel subjected to frictional treatment with a sliding hard-alloy indenter is studied by EBSD analysis, as well as its micromechanical characteristics. It has been found that frictional treatment results in high dispersity of the structure in the steel surface, down to the submicro- and nanocrystalline state. Instrumented microindentation has revealed that, under all the loads, the values of the contact elastic modulus E ∗ of low-carbon (0.17 wt% C) steel after frictional treatment are lower than those in the initial annealed state. Particularly, the mean value of E ∗ decreases from 208 to 168 GPa under a load of 1 gf on the indenter, from 213 to 176 GPa under a load of 25 gf and from 204 to 155 GPa under a load of 200 gf. It is for the first time that the effect of a decrease in the elastic modulus is observed for a carbon steel subjected to frictional treatment. It also follows from the microindentation data that frictional treatment increases the capability of the surface of annealed low-carbon (0.17 wt% C) steel to withstand higher contact loads prior to plastic deformation. © 2018 Author(s).