Fretting corrosion behavior of a Cr-coated Zr-1Nb alloy cladding in simulated PWR primary water environment

The fretting corrosion behaviors of Cr-coated Zr-1Nb alloy claddings with Zr-4 dimple and Inconel 718 spring in simulated PWR primary water were investigated. The results indicated that by increasing the fretting duration from 192 to 427h, the maximum wear depth and volume of Cr coating with dimple increased by 15% and 3%, respectively. In the case of spring as a grinding material, however, the maximum wear depth and volume significantly increased by about 8 and 300 times, respectively. At 427h, the Cr coating was worn through, and oxidation of the underlying Zr-1Nb substrate formed a dual-layered oxide film.