Corrosion of a zinc-coated steel enclosure at the contact interfaces of gasket joints

A typical enclosure for information technology (IT) equipment is made of various sub-assemblies such as enclosure cases, gaskets and I/O connectors, and the shielding effectiveness of the enclosure is largely determined by junctions in the enclosure for electrically connecting different shielding panels or components. Inter-metallic junctions may get corroded and the shielding effectiveness of the enclosure may deteriorate. The identification of the corrosion mechanisms responsible for the shielding degradation of zinc-coated steel enclosures is the primary focus of this study. A series of preliminary experimental investigations were conducted to help in identifying the corrosion mechanisms. Factors contributing to the corrosion process are discussed. This work provides a basis for on-going effort in experimentally quantifying and modeling the corrosion and corrosion-induced shielding-degradation behavior of electromagnetic shielding enclosures.