Research and Analysis about Corrosion on Cupronickel Heat Exchange Tubes of Auxiliary Condenser

摘要

An inspection of a ship revealed severe corrosion in the BFe30 -1-1 cupronickel heat exchange tubes of the auxiliary condenser. After performing eddy current testing on these heat exchange tubes, areas with significant corrosion were selected. Macro observation, chemical composit ion analysis, energy dispersive spectroscopy (EDS), and Raman spectroscopy were used on the selected samples to detect corrosion products and analyze the causes of corrosion. The experimental results indicate that the incomplete removal of oil films during production led to the formation of residual carbon films during heat treatment, which in turn triggered electrochemical corrosion, ultimately becoming the primary factor for the extensive corrosion of the cupronickel tubes. Additionally, residual water st ains after operation are also an important cause of accelerated corrosion in the cupronickel tubes.