Metallurgical analysis of corroded bellows of bellow-sealed valve in lithium flow system

Liquid lithium has been one of the candidates of the tritium breeder and possibly a coolant for the blanket of fusion reactors. The observation of corrosion behavior was conducted on the bellows of the bellow-sealed valve used in a lithium circulation loop at 350–500 °C for about 1500 h. The results were obtained from observation of the surfaces and cross sections. The bellows was found to be fractured and detached. Selective elements were depleted on the surface.

► We investigate the corrosion behavior of SS316L bellows of bellow-sealed valve in liquid lithium at temperature ranging from 350 to 500 °C for 1500 h.
► The bellows was found to be fractured with dissolution of selective elements at the surface.
► Two types of cracks were observed, i.e. intergranular and transgranular.