Abstract
Recently, many kinds of laser surface treatment have been developed and some of them were used in industry. In the present work, a new laser surface treatment was studied to increase the wear resistance of carbon steels and tool steels by using a 2kW CO2 laser facility attached with a beam rotating optical system. The surface of specimens were laser-remelted in the atmos-pheric environment after graphite spray coating to carbuze the steel. This laser material proces-sing is called hereafter laser carburizing. SNCM616 steel, S58C steel and SKS93 tool steel were remelted after graphite coating of different amounts under argon gas shielding at laser powers of 1.2kW, 1.6kW and 2.2kW. In this process, the carbon content of the fusion zone increased linearly with the amount of coated graphite. SNCM616 steel, which contains 0.19 mass% carbon, increased in carbon content up to 0.95 mass% and Vickers hardness up to 700 Hv after laser carburizing. The great advantage of this laser carburizing-is a time saving process in which only several minutes are enough for the dry hardening process.
