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) C9-787-C9-796
DOI: 10.1051/jp4:1993982

High temperature corrosion of water wall tube in coalfired combustion gases

K. Nakagawa¹, M. Kitagawa¹, Y. Tumita² and S. Ooki<sup>3

1</sup>  Research Institute, Ishikawajima-Harima Heavy Industries Co., Ltd. 1-15 Toyosu 3-chome, Koto-ku Tokyo 13, Japan
²  Boiler Basic Design Department, Ishikawajima-Harima Heavy Industries Co., Ltd. 1-15, Toyosu 3-chome, Koto-ku Tokyo 13, Japan
³  Electric Power Research & Development Center, Chubu Electric Company Incorporated, Kitasekiyama 20-1 Ohdaka-Cho Midori-Ku Nagoya 459, Japan

Abstract
The effect of stoichiometry ratio and ash deposits on the corrosion of mild steel and 0.5Cr-0.5Mo steel has been investigated at 450 °C in the simulated combustion gases burning three kinds of coals. Under the assumption that the gas reacts with the metal at the same temperature as the surface and gas has not changed in composition, the corrosion behavior could be estimated from the Fe-S-O phase stability diagram at 450 °C and pseudo equilibrium Ps₂, and Po₂, based on H₂0 : H₂ at 1200 °C for simulated combustion gases. Ash deposits accelerated the corrosion rates of steels. It is considered that ash deposits act as catalyst and shift the gas composition to the low temperature equilibrium state

© EDP Sciences 1993