Grain Size Dependence of Surface Hardness of Laser-Peened Steels

Abstract

The grain size dependence of the surface hardness of laser-peened carbon steels is investigated. Commercial S35C carbon steel annealed at various temperatures to control the grain size were used as samples. A femtosecond laser was used as a laser driver. Vickers microhardness tests were used to estimate work hardening due to plastic deformation caused by laser peening. The hardness of laserpeened samples varied with laser irradiation parameters and average grain size. The hardness measurements revealed the desirable average grain size for laser peening of carbon steel.