High-temperature oxidation behaviour of EN-1.4301 stainless-steel after surface Ce deposition by a modified CVD method

Abstract

The oxidation of EN-1.4301 (18Cr–8Ni) stainless-steel specimens after Ce deposition at 1173 K under synthetic air is studied. Cerium deposition was carried out by pyrolysis of Ce(NO3) aerosols. Thermogravimetric results show that total mass gain after 22 h of oxidation is one order of magnitude smaller than for the untreated specimen, indicating that the deposition treatment is very effective in increasing the oxidation resistance of EN-1.4301 stainless steel. After oxidation the scale is composed mainly of Cr2O3 and Cr–Mn spinels. Preoxidation in air of the stainless steel prior to Ce deposition does not alter significantly the composition of the oxide scale except for a slight increase in iron content and a reduction in mass gain and thickness of the oxide layer. Rutherford backscattering spectrometry data confirm these results and show a homogeneous in-depth distribution of Ce along the oxide scale. The presence of cerium oxide particles in the scale, in contrast to the presence of perovskite phases on depositing lanthanum, suggests that the silica layer found at the alloy/scale interface could be responsible for the reactive element effect. Copyright © 2000 John Wiley & Sons, Ltd.