Fretting Wear Behaviour of Zr Alloy Cladding Tube Under Partial Slip Regime with Different Duration in Simulated Primary Water of Pwr

Abstract

The fretting wear behaviour of Zr alloy cladding tubes under partial slip regime in a high temperature pressurised water was investigated. The fretting regime remained unchanged with the increasing fretting time and hence both the wear volume and depth of the worn scars formed on Zr cladding tubes changed slightly. The wear mechanism was delamination at some local regions, resulting in a slight damage. Third-body layer, oxide layer, tribologically transformed structure layer , and general deformation layer were observed form the cross-section of the worn scar and their formation mechanisms were analysed in detail. Moreover, from the metal/oxide interface to surface, the main oxide transitioned from tetragonal -ZrO 2 to monoclinic-ZrO 2 . Finally, the partial slip regime process and the microstructural evolution during fretting wear were discussed.

Keywords: Fretting wear, Partial slip regime, Zr alloy tube, High temperature pressurised water, Microstructure