Materials Testing in Simulated Flue Gas Desulfurization Duct Environments

摘要

Corrosion of construction materials is a major cause of poor reliability and high costs associated with flue gas desulfurization systems. In particular, the outlet ducts which carry cooled scrubbed gas from the scrubber to the stack suffer severe corrosion. Accordingly, the Electric Power Research Institute (EPRI) has asked Battelle to evaluate alloys and linings in simulated outlet duct environments. Of the alloys tested, the nickel-based alloys Hastelloy C-276®, Inconel 625®, Hastelloy G®, and the iron-based alloy AL 6X®, showed none or very little pitting;this resistance was attributed to their high molybdenum content. Also, titanium was found to be very resistant to the wet acidic environments. Significantly, the ferritic stainless steel Monit , which is a low cost material containing only 4.1 weight percent molybdenum, exhibited high resistance against pitting and uniform corrosion. The 300 series stainless steels showed deep pits and high corrosion rates.