Abstract:
To enhance the performance of the Inconel 690 coating to meet the application requirements of internal components of reactor pressure vessels and control rod drive mechanisms in nuclear power facilities, this study proposed a strategy of introducing ZrC as a ceramic reinforcing phase to increase the hardness and wear resistance of the coating. Through the laser cladding process, ZrC/Inconel 690 coatings with different ZrC contents were deposited on a 304 stainless steel substrate. Based on the microstructure characterization and results of various performance tests, the addition of ZrC can significantly improve the hardness and wear resistance of the coating through the synergistic effects of precipitation strengthening and fine grain strengthening. Among them, the ZrC/Inconel 690 coating with 60wt.% ZrC exhibited the best hardness and wear resistance, and its performance was superior to that of the widely used Stellite 6 coating. However, excessive ZrC content would increase the electrochemical pitting sites, resulting in a decrease in corrosion resistance. Considering all the performance indicators and actual operational conditions, the ZrC/Inconel 690 coating containing 40wt.% ZrC demonstrated the optimal comprehensive performance: a significantly increased microhardness, superior high-temperature wear resistance to traditional Stellite6 coating and comparable corrosion resistance.