Microhardness and tribological wear of the steels remelted with an electric arc

Summary This study presents results of a research on the surface strengthening of the C15, C45 and C90U steels by application of concentrated heat stream with the GTAW methodology. Utilizing the GTAW methodology remelting of the surface layer of the sampled steels was performed by a welding head moving at a speed ranging from 200 mm/min to 800 mm/min and the current intensity of the electric arc ranging from 50A to 300A. Measurements of hardness, frictional coefficient and intensity of tribological wear were performed in the remelted surface layer. Correlation between the intensity of the electric arc versus microhardness and tribological wear resistance under conditions of dry-friction was established. Following the treatment an increase in hardness as well as increase in the tribological wear resistance could be observed in steel samples. The best results were achieved during remelting of the surface layer with electric arc at 100A intensity and the speed of the welding head in relation to treated sample of 200 mm/min.