Formation of Composite Layer Containing Silicon Carbide particles on the A106 Steel Surface by Tungsten Inert Gas (TIG)

In this study, formation ofcomposite coatings containing silicon carbide particles on the ASTM A106-Gr.B steel surface via gas tungsten arc welding process was investigated. For this purpose, silicon carbide particles with different volume percent were applied on the steel surface and melt mixing process with the base metal was completed altering the current density. . Study of microstructure of coatingswas performed by optical microscopy and scanning electron microscope,along with point analysis. The results of the measurements showed that coating had a dendritic structure containing silicon carbide reinforcement that can improve the hardness and the wear behavior of the mentioned coating. Hardness of the coating microhardness tests and wear behavior of coatings was evaluated by the reciprocating wear test. Micro hardness test results were indicative of increasing of hardness of coated samples (of about 650 to 1200 vickers) compared to the uncoated sample (of about 200 vickers). Assessment of wear behavior of coatings revealed a significant improvement in wear behavior of the coatings upon addition ofsilicon carbide reinforcing agent. The main wear mechanism of the uncoated samples was delamination, and wear and surface oxidation, while for the coated samples was delamination, wear and surface oxidation, andadhesive wear.