Effect of long-term aging treatment on the structure and oxidation resistance of Cr coatings under high-temperature steam

Cr coatings were deposited on Zr-4 tubes by arc ion plating to explore the effect of different aging treatment times at low temperature on the steam oxidation performance of Cr coatings. The intrinsic relationship between the coating grain evolution and oxidation behavior after different aging times was analyzed by EBSD. The mid-term aging treatment improve the oxidation resistance of the Cr coating. After long-term aging treatment, a significant amount of Cr2O3 in the grain boundaries close to the Zr-4 substrate preferentially reacts with Zr, which is the reason for the serious degradation of the performance of the Cr coating.