Effect of temperature and atmosphere on fretting wear of self-mated Fe-10Cr-4Al alloy for nuclear power application

Over the years, fretting has been a leading cause of fuel failures for water cooled nuclear reactors. Implementation of liquid lead coolant increases the need for fretting and corrosion-resistant materials. Fe–10Cr–4Al alloy has shown good resistance to thermal aging, oxidation, liquid metal corrosion, and embrittlement in liquid lead environment. The performance of Fe-10Cr-4Al under fretting wear conditions has not been studied previously. This work aims to investigate the fretting wear and friction behaviour of self-mated Fe-10Cr-4Al alloy at varying temperatures, in the presence of a reducing gas environment and liquid lead. The results show that an increase in test temperature from RT to 550 °C decreases the coefficient of friction and promotes the formation of Cr and Fe oxide third body layer. At high temperature in reducing gas atmosphere, the initial plastic deformation and severe adhesion leads to early seizure. Presence of liquid lead has a lubricating effect and allows a third body layer to form on worn surfaces. A detailed description of the initial wear mechanisms of Fe-10Cr-4Al alloy and friction levels under various conditions provides a base for further investigation of this alloy for long-duration fretting wear. • Fretting wear and friction behaviour of Fe-10Cr-4Al in various conditions is studied • High COF, extensive adhesion, and microcracks are typical of room temperature tests • Fe and Cr oxides third body protects Fe-10Cr-4Al from damage at high temperature • High-temperature tests in reducing gas results in severe adhesion and early seizure • Tests in lead shows limited plastic deformation and the formation of a third body