Corrosion Reasons of Reflective Layer of Aluminum Foil with Fiberglass Cloth on Long Heat-Supply Network Pipeline

The reflective layer of aluminum foil with fiberglass cloth on heat-supply network pipeline working in high temperature environment in a power plant was corroded. Samples taken from whitening and blackening areas were observed, and the metal elements on the corroded surface were analyzed by X-ray fluorescence spectrometer. The results show that the chemical reaction between the aluminum foil and the contacted fiberglass cloth caused the calcium content on the surface of the aluminum foil to increase exponentially. The generated symbiotic metallic sediment deposited on the surface, resulting in a decrease in the reflectivity of the reflective layer and an increase in the heat dissipation loss of the pipeline. In addition, the penetration of water vapor also accelerated the occurrence of corrosion.