Modeling the time-dependent acceleration correlation between neutral salt spray and Hainan coastal atmospheric corrosion of 5083 aluminum alloy

Purpose This study aims to establish a corrosion prediction model for Hainan atmospheric environments by comparing the corrosion behavior of 5083 aluminum alloy in neutral salt spray (NSS) tests and outdoor exposure tests in the Hainan coastal atmosphere. Design/methodology/approach The 5083 aluminum alloy was subjected to various exposure durations in both NSS tests and outdoor tests in Hainan Coastal. After testing, multiple characterization methods – including energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and x-ray diffraction (XRD) – were used to examine the samples, and the indoor and outdoor data obtained were compared and analyzed accordingly. Findings While both environments produce Al(OH)3 and Al2O3, the outdoor Hainan exposure uniquely promotes the formation of the AlO(OH) phase, influenced by the intense wet–dry cyclic effects of the tropical coastal environment. The NSS acceleration factor was found to be time-dependent rather than constant, reflecting the distinct protective evolution of corrosion layers under these specific experimental systems. Originality/value By analyzing the indoor and outdoor experimental data, this study establishes a non-constant rate model describing the correlation between indoor and outdoor corrosion behavior, whose kinetic framework may provide a basis for predicting corrosion trends under the specific conditions investigated.