Technical Root Cause Analysis of Localized Corrosion in Wet Flue Gas Desulfurization Slurry at Coal-Fired Power Stations

摘要

Recent experience with stainless steels in wet flue gas desulfurization service has shown rapid localized attack. This paper discusses a brief historical perspective on the material performance in wet flue gas desulfurization (WFGD) and the findings of a technical root cause analysis (TRCA). Observations of attacked WFGD absorbers shows pitting and crevice corrosion near welds in the immersion zone and inside spray headers. All of the absorbers that were the subject of the TRCA were forced-oxidation limestone absorbers. Vertical spray towers and jet bubbling reactors were inspected and discussed.