Fe-14Ni-14Cr-2.5Al steel showing excellent corrosion-resistance in flowing LBE at 550 ℃ and high temperature strength

We investigated the corrosion behavior, microstructural evolutions, and mechanical properties in an alumina forming austenitic (AFA) Fe-14Ni-14Cr-2.5Al steel after exposure in the flowing lead-bismuth eutectic (LBE) at 550°C for 4008 h and aging in air for 5000 h. The results showed that the AFA steel exhibited not only excellent corrosion-resistance in the flowing LBE but also a strong stability of austenite and high yield strength (589 MPa) at 550°C. The excellent corrosion-resistance was ascribed to the rapid formation of a thin Al2O3 scale. For the first time, the precipitation of γ'-Ni3Al phase was observed in the AFA steel after long-term aging at 550 ℃.