Effect of heat input on Stellite 6 coatings on a medium carbon steel substrate by laser cladding

Stellite 6 was deposited by laser cladding on a medium carbon steel substrate (MS) with energy inputs of 1. kW (MS 1) and 1.8. kW (MS 1.8). The chemical compositions and microstructures of these coatings were characterized by atomic absorption spectroscopy, optical microscopy and scanning electron microscopy. The microhardness of the coatings was measured and the wear mechanism of the coatings was assessed using a pin-on-plate (reciprocating) wear testing machine. The results indicated less cracking and pore development for Stellite 6 coatings applied to the medium carbon steel substrate with the lower heat input (MS 1). Moreover, the Stellite coating for MS 1 was significantly harder than that obtained for MS 1.8. The wear test results indicated that the weight loss for MS 1 was much lower than for MS 1.8. It is concluded that the lower hardness of the coating for MS 1.8, markedly reduced the wear resistance of the Stellite 6 coating.