Failure Analysis of Float Valve in Transformation Gas Separator of Coal Gasification Unit

Corrosion failure of a float valve in transformation gas separator unit occurred after servicing for 7 months.The failure reasons were analyzed by observation of corrosion morphology,analysis of chemical composition,examination of microstructure and analysis of corrosion products.The results show that a large amount of deformation induced martensite occurring in cold machining reduced the corrosion resistance of the float valve greatly.The joint action of activation corrosion caused by H₂S and pitting caused by Br^- made the float valve fail seriously.