Microstructural Properties of Fe-Cr-C/NbC Composite Coating Produced on Medium Carbon Steel Surface by TIG Coating Process

Abstract

In this study, Fe-based composite coatings were produced on a medium carbon steel surface by the Tungsten inert gas method. The microstructure and phase structure of the coatings were analyzed by an optical microscope with clemex image analysis, scanning electron microscope equipped with an energy-dispersive spectroscopy and X-ray diffractometer. The results show that the coating is metallurgically bonded to the substrate when it is produced with sufficient energy input. In the microstructure of Fe-Cr-C coatings, hexagonal-shaped M7C3 carbides solidified in gamma-(Fe,Cr) eutectic matrix, while in Fe-Cr-C/NbC composite coatings, quadrangular-shaped NbC carbides solidified. As the amount of FeNb melted increased, the amount of NbC in the structure increased.