Development on fatigue testing of hardfaced components in sodium cooled fast reactors

Components in a nuclear reactor like Sodium Cooled Fast Reactor (SFR) are hardfaced with suitable coating material to avoid self-welding of components caused due to liquid metal coolant which acts as a metallic gum. Tensile stresses are observed at interface of base metal and coating due to difference in their coefficients of thermal expansion which leads to thermal fatigue failure at higher operating temperatures. This reduces the bonding strength between surfaces and also cause delamination of coating. Thus, selection of coating materials with good creep and fatigue life for achieving high breeding ratio and high fuel burn up is important. It is thus required to carry out design of SFR hardfaced components considering the fatigue parameters. This paper gives a review on need to study the fatigue characteristics of SFR components along with need for hardfacing of SFR components. This paper also reviews the fatigue testing methods and fatigue behaviour of various hardfaced materials like low carbon low nitrogen stainless steel (SS), low alloy steels, carbon steels, chromium enhanced steels, high strength steels etc. which are used as materials for different SFR component systems. Fatigue behaviour of cladded components for few other applications is also presented.

Automated summary

This paper discusses the need for hardfacing of components in a Sodium Cooled Fast Reactor (SFR) and explores the importance of studying fatigue characteristics. Selecting coating materials with good creep and fatigue life is essential for achieving high breeding ratio and high fuel burn up.