FE-CR-AL ALLOY, HIGH-TEMPERATURE CORROSION IN SULFUR VAPOR

The corrosion of Fe-17Cr-xAl [x = 4 or 6 weight percent (w/o)] steels is studied at high temperature (750”-950°C) under a low sulfur vapor pressure (6.2 × 10-2 Torr). Observation and analysis of the kinetic curves obtained allowed several successive corrosion steps to be clarified. The study of the morphology and the composition of the corrosion scales show their transformation during the difierent steps of the sulfidation process. All the results obtained allow a mechanism of corrosion, closely dependent on the mechanical stresses developed in the scales during the reaction, to be proposed. © 1979, The Electrochemical Society, Inc. All rights reserved.