The Wear Behavior between Zirconium Alloy and Inconel under Water Condition using Pin-on-disk Wear Tester

The spacer grid is one of the key component in the pressurized water reactor (PWR) fuel assembly. The most important function is to hold the fuel rods to maintain the distance between the fuel rods inside a fuel assembly. In the operating power plants, a fretting damage has been frequently reported between nuclear fuel rod and its supporting spring/dimple of the grid assemblies. Fretting damage is generally caused by fretting wear, which includes various wear mechanisms such as an oxidative, adhesive, abrasive wear etc. or fretting fatigue, including a surface or bulk fatigue. According to the previous researches, most of the studies have been performed with Zirconium to Zirconium alloy because the severe wear occurred at these contact area. Top and bottom grids are made from Inconel, thus, the specimens made of Inconel and Zirconium alloy were chosen in this study. Although any noticeable wear cannot be seen on the fuel rod surface supported by the Inconel grid, this study will be helpful to understand wear phenomenology