Environmental Damage Behavior of 2A12 Aluminum Alloy under Coupling Action of Marine Atmospheric Environment and Tensile-Compressive Load

The coupling test of marine atmospheric environment and tensile-compressive fatigue load for 2A12 aluminum alloy was carried out in outdoor environment of Hainan station by coupling test equipment of mechanical load. The coupling effect of marine atmospheric environment corrosion and tensile-compressive fatigue load on the environmental damage behavior of 2A12 aluminum alloy was discussed from the aspects of corrosion morphology, tensile properties and fracture morphology. The results show that the corrosion characteristics of 2A12 aluminum alloy in coupling test and static exposure test are consistent. The corrosion depths of the static exposure test for 6 months and the coupling test for 35 days are 71 μm and 121 μm, respectively. The results of tensile properties show that the decrease rate of tensile properties of 2A12 aluminum alloy are accelerated by the coupling effect. And the accelerated ratio of the coupling test was more than 10 times that of the static exposure test. The fracture morphology shows that the coupling fracture crack of 2A12 aluminum alloy starts from the corrosion surface, and the crack source and propagation zone are quasi-cleavage fatigue crack propagation characteristics. The coupling test results are closer to the actual situation of equipment, which has important reference value for the design and material selection of bearing structure.