Abstract
Research shows that chromate can offer a large, 10 fold, reduction in corrosion fatigue crack growth rates when added to a bulk sodium chloride (NaCl) solution in high concentrations, and can inhibit corrosion fatigue when added to a bulk NaCl solution in concentrations relevant to inhibitor leaching studies. However it remains unclear if chromate epoxy based primer can inhibit corrosion fatigue under atmospheric corrosion conditions. The protection provided by corrosion inhibitors under fatigue conditions can be affected by loading conditions (∆K, frequency) but it is also likely affected by the environmental effects on inhibitor leaching (pH, chloride concentration, temperature, coating degradation). An improved understanding of how environment and loading parameters influence a coating’s ability to offer protection against corrosion fatigue damage would greatly help the coating community to design more robust coatings and better evaluate new coating protection systems. This work includes research on the effect environment and corrosion protection systems (chromate coatings) on legacy aluminum alloy UNS A97075 with respect to environmentally assisted fatigue damage.
