High-Temperature Sulfidation of Crofer 22APU in atmospheres containing H2S and H2O

The work presents analyses of Crofer 22APU steel oxidation in hydrogen atmosphere containing 300 ppm H2S and in hydrogen atmosphere containing 300 ppm and 1% H2O. The oxidation process was conducted on two kinds of samples: pre-oxidized (pre-oxidation process was carried out in the air at a temperature of 800 degrees C during 100 h), and not pre-oxidized at a temperature of 600 and 800 degrees C using periodic method during 500 h. It was established that oxidation rate may be described by means of parabolic law. Determined parabolic rate constants indicate that not pre-oxidized samples undergo sulphurization in H-2/300ppm H2S atmosphere, while in H-2/300ppm H2S + 1%H2O atmosphere they undergo oxidation 3-4 orders of magnitude slower.