Corrosion of ferritic-martensitic steels in the eutectic Pb-17Li

Three different ferritic-martensitic steels were exposed to Pb-17Li under d ynamic conditions at 480 degreesC up to 8000 h. On the surface of all 7-10% Cr reduced-activation steels, a two-layer oxide scale consisting of MnCr2O 4 spinel and (Fe,Cr)(2)O-3 formed during the heat treatment. This was detec ted by means of XPS and BES analysis. It was found that the corrosive attac k started with the dissolution of MnCr2O4 spinel and (Fe,Cr)(2)O-3. When th e oxide scale was dissolved by the liquid metal the corrosive attack contin ued into the steel matrix. Investigations of the corrosion mechanism have r evealed that the steel elements Fe and Cr were strongly dissolved. Those st eel elements, which have a low solubility in Pb-17Li, like W, Mo, V, remain ed in the matrix and were enriched in the surface near layer. (C) 2000 Else vier Science B.V. All rights reserved.