High-temperature oxidation and diffusion behaviours of YG6X and Inconel625

Abstract

To study the oxidation resistances of tool material (carbide YG6X) and workpiece material (superalloy Inconel625), an oxidation resistance experiment was carried out in a high-temperature furnace. The high-temperature oxidation products were analysed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). A diffusion behaviour experiment was conducted on the elements of YG6X and Inconel625 in a vacuum tube furnace, and the specimens from the experiment were analysed using electron energy disperse spectroscopy (EDS). The analysis (experiment) results show that YG6X oxidised at 973 K, and WO3 sublimated at approximately 1100 K, exhibiting a poor oxidation resistance at high temperature. Inconel625 oxidised and formed a dense Cr2O3 oxide layer on the surface at approximately 1073 K, maintaining a good oxidation resistance until a temperature of 1273 K. The contents of the matrix elements decreased because of the diffusion between YG6X and Inconel625. As the temperature increased from 873 K to 1273 K, the diffusion was significant. The intrinsic element concentration decreased significantly, and the element diffusion depth increased. Following is the order of the diffusion degree of the five elements in YG6X and Inconel625: W > Ni > Cr > C > Co.