Effect of Pickling on Fretting Wear and Corrosion Behavior of Zr-4 Alloy

Fretting wear and corrosion test was performed to Zr-4 alloy for pressurized water reactor (PWR) fuel cladding in a water environment of high temperature and high pressure. The 3D profile, surface morphology and chemical composition of the samples after fretting wear and corrosion tests were analyzed by 3D white light interferometer, optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The results show that the wear and corrosion coefficients of the Zr-4 alloy with and without pickling were 6.26×10^-16 Pa^-1 and 3.3×10^-16 Pa^-1 respectively. Adhesion and abrasion was the main damage mechanism for the Zr-4 alloy and plastic deformation was also found. Surface pickling removed the hardened layer forming on the surface of the material during processing, making the surface of the material more prone to scratch, thus reducing the wear and corrosion resistance of the material.