Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température
J. Phys. IV France 03 (1993) C9-327-C9-330
Sulfidation of Fe-Cr binary alloys in H2/H2S atmosphere at 873- 1073 KZ. Zurek and J. Gawel
Cracow University of Technology, 31-155 Krakow, Poland
Sulfidation of Fe-Cr binary alloys has been studied in H2/H2S atmosphere in the temperature range 873-1073 K. Alloys containing respectively 3, 10, 26 and 45%wt. of chromium were investigated. Sulfur partial pressure in the gas mixture was pS2 = 10-3 Pa . Morphology of the obtained scales was studied by SEM. In spite of the results of Narita, Smeltzer and Nishida who have found a two layer scale, scales in this survey consisted apparently of one layer in the entire range of temperatures and alloy compositions. Scale composition was determined by X-ray diffraction. Diffraction patterns of scales formed on Fe45Cr exhibited the presence of Cr3S4 whereas FeCr2S4 was found on Fe26Cr. The latter compound was also observed in scales formed on Fe10Cr and Fe3Cr, though in these spectra some peaks were difficult to interpret. Kinetic measurements taken by a spring microbalance confirmed the results of Narita et al. and the reaction rate increased only slightly with increases in chromium content in the alloy.
© EDP Sciences 1993