The effect on wear behaviour of H13 tool steel surfaces modified using a tungsten arc heat source

The surface modification of an H13 tool steel using a tungsten arc heat source was studied. The investigation shows that, when surface melting was performed in a controlled atmosphere of N2, CO2 or CO2–Ar mixture, the wear resistance of the surfaces was significantly enhanced over the untreated steel. The most wear-resistant surface was that for N2 and the least for surfaces melted in a CO2–Ar mixture. The resolidified surface microstructure consisted primarily of δ ferrite with some retained austenite and the increase in wear resistance was attributed to an increase in surface hardness due to the formation of carbo-nitride precipitates within the modified surfaces.