Inhibition of Ant’s–nest Corrosion Progress with Heating and Drying

Abstract

Ant’s–nest corrosion forms three–dimensional and complex pits in a copper tube. This corrosion gives fatal damage to air conditioners. Although improvements in material design and operating environment have been proposed for avoiding this corrosion, there are some practical problems associated with operation cost and performance of the corrosion inhibition.

This paper proposed a new method for inhibiting the ant’s–nest corrosion by applying repetitive heating and drying during operation of the copper tube. It was confirmed that this method exhibited reliable performance toward corrosion inhibition without requiring special materials or surface treatments. SEM and CT scanning system were performed to analyze morphology of the corrosion pits. EDS was employed to analyze chemical composition inside the pits. The results confirmed that the repetitive heating and drying causes restoration of corrosion inhibition.