Development of New Accelerated Corrosion Test for Zinc-Coated Steel Sheets used in Electrical Appliances

摘要

i) The corrosion of used electrical appliances collected from four domestic regions in Japan was investigated. The corrosion of air-conditioners used outdoors was influenced by the distance from the seashore and the installed location, and the amount of deposited sea salt was confirmed as the main corrosion factor. ii) The conventional accelerated corrosion tests were not significantly correlated with the actual environment from the perspective of corrosion morphology and the ranking of corrosion resistance. It is suggested that conventional accelerated corrosion tests cannot be used for evaluating the corrosion resistance of zinc-coated steel sheets with the chromate-free coatings that will be used from now on. iii) A new accelerated corrosion test for zinc-coated steel sheets used in electrical appliances, which is based on the actual corrosion conditions of electrical appliances and the problems of conventional accelerated corrosion tests, was developed. The new accelerated corrosion test makes it possible to appropriately evaluate the corrosion resistance of zinc-coated steel sheets with chromate-free coatings.