Surface Hardening of Carbon Steels by High power CO2 Laser

Abstract

In this work surface hardening treatment of carbon steel specimens, that having a carbon contents ranging between 0.25 and 2.44%, was done using CO2 laser having 10.6μm wavelength, 100μm spot size and with powers ranged between 100-300 W. The dependence of the surface hardness on laser power (laser intensity), scanning speed (exposure time), specimen carbon content and specimen thickness were performed. It was shown that the enhancement in target surface hardness increased with laser power and decreased, with increasing the scanning speed for fixed power. Also it was found that, the enhancement in target surface hardness was increased with the increasing in carbon percentage and decreased when the target was thicker. High power laser hardening technique proves the possibility of controllable hardness enhancement via controlling the laser interaction parameters.