A novel investigation on the cast iron corrosion in polluted phosphoric acid

Abstract

The effect of fluoride ions on cast iron corrosion resistance in polluted phosphoric acid using electrochemical measurements, UV–Vis–NIR spectroscopy equipped with the integrating sphere, and scanning electron microscopy (SEM) was investigated. Electrochemical measurements revealed that the fluoride ions favor the anodic dissolution, and catalytically enhance the dissolution processes by changing the reaction mechanisms, leads to growing less stable oxide film on the metal surface. Moreover, the UV–Vis–NIR spectroscopy showed that fluoride prohibits the iron and chromium to enrich the material surface. Finally, the SEM analysis proved that the austenitic matrix is the weakest matrix.