Liquid metal corrosion of T91 and A316L materials in Pb-Bi eutectic at temperatures 400-600 °C

The corrosion resistance of T91 and A316L materials was tested in stagnant liquid lead-bismuth eutectic (LBE). The materials were exposed for 175, 500, 1250, 2300 and 3000 11 at temperatures front 425 to 600 degrees C under 5%H-2+Ar cover gas atmosphere. Severe corrosion occurred at temperatures above 500 degrees C where three corrosion modes were distinguished: stable oxide film mode, transition mode, and final dissolution mode featuring Cr and Ni leaching and material loss. The principle corrosion mechanisms were uniform penetration and dissolution of the penetrated volumes. At these temperatures (>500 degrees C) T91 had a better corrosion resistance (corrosion rate similar to <= 137 mu m/year) compared to A316L (<= 250 mu m/year). The transition corrosion mode continued 2-3 times longer for T91 material due to residual oxides found even after 3000 It of exposure. At low temperatures (<450 degrees C) both materials showed good corrosion resistance but A316L performed better than T91 with corrosion rates 2-5 times lower. (C) 2005 Elsevier Ltd. All rights reserved.