EDP Sciences Journals List
Issue J. Phys. IV France
Volume 03, Number C9, Décembre 1993
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
Page(s) C9-197 - C9-204
DOI http://dx.doi.org/10.1051/jp4:1993918

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) C9-197-C9-204

DOI: 10.1051/jp4:1993918

High temperature corrosion of MA 956 in sulfidizing/oxidizing/carburizing environments : a study of the influence of preoxidation on the corrosion resistance of the alloy

F. Uberti1, F. Gesmundo2 and G.P. Toledo3

1  Lab. of High Temperature Corrosion, CISE SpA, V. Reggio Emilia 39, 20090 Segrate (MI), Italy
2  Istituto di Chimica, Università di Genova, Fiera del Mare, Pad. D, 16129 Genova, Italy
3  ENEL/DSR-CRTN, Via Monfalcone 15, 20132 Milano, Italy


Abstract
The influence of preoxidation and of the presence of HCl or of char deposits upon the high temperature corrosion of MA 956 in simulated coal-gasification environments has been studied at 700°C for periods up to 2000 h. The corrosion of the blank material produced mixed Al-Cr sulfide-oxide scales, while preoxidation led to the development of alumina scales well adherent to the substrate which were quite protective since no sulfide formation was observed even after 1000 h exposure to the sulfidizing gases. On the contrary, HCl produced a significant enhancement of the corrosion rate of the bare alloy : however, preoxidation was able to afford a reasonable degree of protection even in this case. Coal chars had little effect on the corrosion in the absence of HCl.



© EDP Sciences 1993