Naturally Occurring High-Chloride Coal and Superheater Corrosion—A Laboratory Study

Abstract

DOE Provided funds for C-E to investigate the fireside corrosion potential of commercial boiler tube alloys at elevated temperatures when exposed to the combustion products from a series of coals. The results of the laboratory and field tests were previously reported. In a supplementary phase of the program, C-E tested for the effect of chloride on similar alloys while firing a naturally occurring high chloride Midwestern bituminous coal in the same laboratory furnace. On the basis of exposure in the convection pass at temperatures from 1100–1700°F, Inconel Alloy 690 was found to have very good resistance to corrosion while Incoloy 800H and Tp-310 s. s. were good transitional materials. Poor materials were T-22, 316 s. s., Inconel 617, and Inconel 671.