Behavior of steels in flowing liquid PbBi eutectic alloy at 420-600 °C after 4000-7200 h

This paper presents the results of steel exposure up to 7200 h in flowing LBE at elevated temperatures and is a follow-up paper of that with results of an exposure of up to 2000 h. The examined AIR 316 L, 1.4970 austenitic and MAN-ET 10Cr martensitic steels are suitable as a structural material in LBE (liquid eutectic Pb45Bi55) up to 550 degreesC, if 10(-6) of oxygen is dissolved in the LBE. The martensitic steel develops a thick magnetite and spinel layer while the austenites have thin spinel surface layers at 420 degreesC and thick oxide scales like the martensitic steel at 550 degreesC. The oxide scales protect the steels from dissolution attack by LBE during the whole test period of 7200 h. Oxide scales that spall off are replaced by new protective ones. At 600 degreesC severe attack occurs already after 2000 and 4000 h of exposure. Steels with 8-15 wt% Al alloyed into the surface suffer no corrosion attack at all experimental temperatures and exposure times. (C) 2004 Elsevier B.V. All rights reserved.