Corrosion Behavior of 3A12, 5052, 6063 Aluminum Alloys in Coastal Atmosphere

Salt spray was used to simulate the coastal atmospheric environment. The corrosion law and mechanism of 3A12, 5052, 6063 aluminum alloys in coastal atmospheric environment were studied by weight loss method, optical microscopy, X-ray diffraction (XRD) and electrochemical technique. The results show that the corrosion mass loss and corrosion time of the three grades of aluminum alloy were in a power exponential relationship, with the same corrosion products and similar corrosion laws. At the initial stage of corrosion, pitting corrosion occurred in the three kinds of aluminum alloy under the action of Cl^-, and then pitting corrosion developed into general corrosion, and the corrosion product layer thickened during the overall corrosion process. And then corrosion further developed, and the outer corrosion product fell off, leaving a dense layer of corrosion products. Electrochemical test results show that the corrosion resistance order of the three grades of aluminum alloy in the coastal atmospheric environment was as follow:5052 > 6063 > 3A12.