Sulfidation of Fe-Cr binary alloys in H2/H2S atmosphere at 873- 1073 K

Z. Zurek; J. Gawel

doi:doi:10.1051/jp4:1993932

Proceedings of the 3rd International Symposium on High Temperature Corrosion and Protection of Materials
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
DOI: 10.1051/jp4:1993932

Sulfidation of Fe-Cr binary alloys in H₂/H₂S atmosphere at 873- 1073 K

Z. Zurek and J. Gawel

Cracow University of Technology, 31-155 Krakow, Poland

Abstract
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 p_S₂ = 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.