Mechanical and fatigue properties of martensitic Fe-13Cr steel in contact with lead and lead-bismuth melts

• We investigated the influence of Pb and Pb-Bi melts on mechanical properties of Fe-13Cr steel at high temperatures.
• We revealed the temperature interval of liquid metal embrittlement of Fe-13Cr steel.
• Pb-Bi has more negative impact as compared with Pb for both plasticity and fatigue.

The influence of stagnant liquid-metal environments (Pb and Pb-Bi) on mechanical (strength and plasticity) and fatigue properties (low cycle fatigue) of martensitic Fe-13Cr steel in temperature interval of 250–600 °С have been investigated. Heavy liquid metals facilitate decreasing in ultimate strength by 10–20% against that in vacuum. The increase of temperature enhances this effect. Fe-13Cr steel is susceptible to liquid-metal embrittlement in the temperature interval of 350–450 °С, which manifests itself more substantially in lead-bismuth eutectic. The decrease of plasticity in Pb is 11% at 450 °С and in Pb-Bi is 30% in temperature interval 350–400 °С. Liquid metal environments significantly reduce fatigue life of Fe-13Cr steel. Pb-Bi has a more negative impact. In particular, with increasing total strain amplitude (up to 1.0%), the decrease in the cycle number to fracture by more than two orders of magnitude occurs.