Effect of coastal atmospheric corrosion on fatigue properties of 2024-T4 aluminum alloy structures

摘要

To investigate the effect of atmospheric corrosion on the fatigue properties of 2024-T4 aluminum alloy structures during the whole corrosion period, atmospheric and accelerated pre-corrosion fatigue tests were carried out. Field exposure tests were carried out for 7, 12, and 20 years. A laboratory accelerated corrosion test method was proposed to simulate the whole atmospheric corrosion period from initial pitting to the subsequent exfoliation corrosion, and the reliability was verified through an analysis of the corrosion morphology, corrosion products, and thickness variation. Pitting and intergranular corrosion occurred after a short exposure to atmospheric corrosion, and intergranular corrosion was the dominant corrosion damage mode. The fatigue cracks initiated at the deepest boundary of intergranular corrosion. The fatigue life decreased dramatically during the initial stage of atmospheric corrosion and then decreased more slowly. Finally, the mechanism through which atmospheric corrosion affected the fatigue properties was analyzed. (C) 2019 Elsevier B.V. All rights reserved.