ANT-NEST CORROSION OF COPPER TUBES IN AIRCONDITIONING SYSTEMS

摘要

In air conditioning applications premature failure of copper tubing frequently occurs due tornpitting corrosion after a short period in service and even during leakage tests after installation. Thisrntype of corrosion is described in the literature as ant-nest (formicary) corrosion. Ant-nest corrosionrnmorphology is characterized by microscopic caverns connected by tunnels.rnCopper tubes used in a commercial air conditioning system were analyzed to assess the reasons forrntheir premature corrosion failure during leakage tests after installation and during their first two monthsrnin service. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and X-rayrnphotoelectron spectroscopy (XPS) were the techniques utilized. Volatile organic acids, chlorine andrnsulfur, originated by the manufacturing processes, were identified as possible sources of the prematurerncopper corrosion failure.