Dilution and C Content Estimation of Stellite 6 Fabricated on a 1050 Steel Substrate by Laser Cladding

摘要

Stellite 6 was fabricated by laser cladding on a 1050 steel (MS) substrate with laser powers of 1 kW (MS-1) and 1.8 kW (MS-1.8). The chemical compositions and microstructures of the coatings were analysed by X-Ray Fluoroscense, optical microscopy and scanning electron microscopy. The microhardness of the coatings was examined and the wear mechanism of the coatings was evaluated using a ball-on-plate wear testing machine. The results indicated less cracking and pore development for Stellite 6 coatings applied to the 1050 steel substrate with the lower laser power (MS-1). Moreover, the Stellite coating for MS-1 was significantly harder than that obtained for MS-1.8. The wear test results showed that the weight loss for MS-1 was much lower than for MS-1.8. The evaluations of dilution and calculation of carbon content indicated that MS-1 has lower dilution and higher coating C content than MS-1.8. It is concluded that the lower hardness of the coating for MS-1.8, substantially reduced the wear resistance of the Stellite 6 coating and the lower hardness of the coating for MS-1.8 was due to higher level of dilution and lower coating C content. The coating-substrate couple must be considered in assessing the likely performance of the coating under service conditions.