LIFUS II corrosion loop final design and screening of an Al based diffusion coating in stagnant LLE environment

Abstract

Corrosion phenomena of structural material in Lead-Lithium Eutectic (LLE) environment is influenced by the coolant chemistry, temperature, velocity profile and impurities concentration dissolved in it. In the framework of the EUROfusion consortium, the Experimental Engineering Division (FSN-ING) by the ENEA Brasimone Research Centre (RC) is developing scientific activities to investigate the corrosion rate of materials and to test Al based diffusion coating at 550 °C, different velocities (0.01, 0.1 and 1 m/s) and different exposure times. To this end, a new experimental facility, named LIFUS II (Lithium for Fusion II) is under construction at the Brasimone RC laboratories. Piping and components installed in the hot leg of the facility are internally coated by an Al based diffusion coating developed in collaboration with RINA Consulting-CSM to reduce concentration of corrosion product in the loop. A preliminary screening of the coating was performed in LLE stagnant conditions at 550 °C for 1000 h showing a good resistance and no signs of dissolution were detected. The only modification on the surface was found to be related to the formation of dark islands made of Al2O3.