A comparison between the chemical behaviour of lead-gold and lead-bismuth eutectics towards 316L stainless steel

Abstract

Summary Lead-gold eutectic (LGE) has been recently proposed as an alternative target material for high power spallation sources. In order to compare the corrosive properties of LGE to the better-studied eutectic of lead-bismuth (LBE), an isothermal twin-loop made of SS 316L was built and operated at the Institute of Physics of the University of Latvia. We have measured the concentration of steel alloying elements dissolved in both alloys at the end of two test campaigns via ICP-OES. In case of LGE, a pronounced concentration increase of Fe, Ni, Mn and Cr is found in the liquid metal, which is significantly higher compared to LBE. Similar results were obtained during complementary investigations on material samples exposed to both alloys in this twin-loop at 400 ◦C and 450 ◦C. These findings indicate that in contact with LGE, SS 316L steel suffers from substantial chemical attack. Detailed investigations using structure materials other than SS 316L have to be undertaken before qualifying LGE as a serious alternative to LBE.

A Review of Corrosion Behavior of Structural Steel in Liquid Lead–Bismuth Eutectic

“…This is usually characterized by the transfer of material components for example, Ni, Fe, or Cr to the liquid phase, continuing until saturation [14]. In the isothermal liquid metal loops for 316L corrosion experiments, the content of each alloying element in LBE was measured as shown in Table 1 [47]. Due to the different solubility and dissolution rates of different elements in LBE, selective dissolution of steel materials tends to occur in LBE.…”

“…In dissolution-based liquid LBE corrosion, the degree of corrosion in liquid LBE varies due to the large difference in the solubilities of various metal elements in liquid LBE [9,38,47,48,86]. Elements such as Si, Al, Cr, and Ni have a strong influence on the corrosion of structural materials in liquid LBE.…”

“…The concentration of elemental impurities in LBE and the actual measured composition of 316L stainless steel. Data transferred from Ref [47]…”