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

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.

Automated summary

The study found that Fe-based composite coatings were produced on medium carbon steel surface using the Tungsten inert gas method, with sufficient energy input resulting in a metallurgical bond to the substrate. In the microstructure, hexagonal M7C3 carbides solidified in gamma-(Fe,Cr) matrix in Fe-Cr-C coatings, while quadrangular NbC carbides solidified in Fe-Cr-C/NbC composite coatings, with the amount of NbC increasing with the melted FeNb amount increasing.