INVESTIGATIONS ON THE SULFIDATION BEHAVIOR OF A Fe-Cr-Al ALLOY.

This study deals with the interaction of a Fe-20Cr-4. 5Al alloy with two types of environments: those which are purely sulfidizing and those in which both oxygen and sulfur are present. H//2-0. 5%H//2S gas mixtures were used to study the former type of interaction in the 800-1100 degree C temperature range, the aim being to investigate whether a protective Al//2S//3 scale would selectively form under these conditions. Mixed oxidizing-sulfidizing conditions were established using H//2-0. 5 H//2S-CO//2 gas mixtures having various levels of CO//2; these studies were carried out at 800 degree C. A thermogravimetric technique using a Cahn 1000 Electrobalance was used to establish the corrosion kinetics while the corrosion products were characterized using scanning electron microscopy and electron probe microanalysis.