Liquid metal embrittlement of the T91 steel in Lead-Bismuth Eutectic: effect of the loading rate and oxygen content

摘要

The mechanical behaviour of the T91 martensitic steel tempered at 750℃ has beenstudied in liquid lead-bismuth eutectic (LBE). Several conditions were considered topoint out the most sensitive embrittling factor. Then, Small Punch Test has been performedin air, in Ar-3.5%H_2, in low oxygen content LBE and in oxygen saturated LBEat different temperatures and different loading rates. The T91 steel exhibited in generala high degree of ductility. However, even with oxygen saturated LBE, it has beenpossible to observe LME at low strain rate. Furthermore, low oxygen content in LBEand an increase in temperature promoted the LME. The strain rate appeared as thecritical parameter for the occurrence of LME of the T91 steel in LBE.