Effect of temperature on liquid metal embrittlement susceptibility of an Fe10Cr4Al ferritic alloy in contact with stagnant lead-bismuth eutectic.

The effect of temperature on the liquid metal embrittlement (LME) susceptibility of an Fe10Cr4Al ferritic alloy exposed to stagnant oxygen-depleted lead-bismuth eutectic (LBE) was investigated using slow strain rate tensile (SSRT) tests. The results show that the total elongation to rupture of the specimens tested in LBE decreases with increasing temperature from 150 to 350 °C, while an upward trend is observed in the temperature range of 350–500 °C. Such a strong temperature dependence is called a "ductility trough". This phenomenon is not observed in the specimens tested in Ar reference environment. Fractographic examinations reveal that LME occurs at 150 up to 450 °C and ductility fully recovers only at 500 °C. In addition, transgranular cleavage and intergranular cracking are the major fracture modes on the fracture surfaces affected by LME. • A "ductility trough" is found and the alloy is embrittled at 150–450 °C. • Ductility recovers only at 500 °C. • Cleavage and intergranular cracking are the major LME failure modes. [ABSTRACT FROM AUTHOR]