Microstructural analysis of SS316L steel wetting in Lithium flow. Part I.

E. Platacis¹ - F. Muktepavela² - A. Shishko¹ - A. Sobolev¹ - A. Klyukin¹ - A. Zik¹

¹ Institute of Physics, University of Latvia, Salaspils LV2169 , Latvia
² Institute of Solid State Physics, University of Latvia, Riga LV1063, Latvia

Abstract
An experimental research is described performed in a vacuum system equipped with a device allowing experiments on wetting the surface of steel SS316L in liquid lithium flow at various process parameters (degree of vacuum, temperature, cleanness of the liquid lithium surface, etc.). The wetting and spreading processes were estimated using a video system in the vacuum chamber and by microstructural analysis after solidification of lithium. It is found that the oxidized steel surface does not prevent wetting at any temperature. At the same time, the presence of lithium oxides is a barrier factor for wetting at low temperatures (up to 450\degC). Cleaning of the liquid lithium surface using a special original lithium injector device has resulted in a successful complete wetting at 350\degC. The device with a Li injector can be used in the future designs of lithium loops. Figs 7, Refs 17.