The Effect of Sulfur on the Carburization of Three Fe–19Ni–21Cr–xAl (x = 0, 2, 6 at.%) Alloys at 900 °C in Oxygen-Contaminated CH4–H2–H2S Atmospheres

Abstract

The effect of sulfur on the carburization of three Fe–19Ni–21Cr–xAl (x = 0, 2, 6 at.%) alloys was studied at 900 °C in three CH4–H2–H2S gases providing different sulfur pressures. For all alloys, the carbon attack decreased with an increase in the sulfur pressure, even if it was never prevented completely. However, reaction with the gas richest in H2S produced also an external chromium sulfide scale. The overall corrosion rates were slower for Fe–19Ni–21Cr–6Al than for the other two alloys under each gas mixture due to the formation of some alumina in the external scales.