6061铝合金在模拟工业-海洋大气环境下的腐蚀研究

The corrosion behavior and mechanism of 6061 aluminum alloy in simulated industrial-marine atmospheric environment were studied by means of UV radiation aging and cyclic wet-dry experiment, and the analyses of corrosion morphology of surface and cross section, mechanical property and tensile fracture. The morphology observation showed that the corrosion of 6061 aluminum alloy in this environment was initiated by pitting corrosion, the intergranular corrosion occurred and aggravated with the time increased, and the deepest crack of intergranular corrosion reached 80 μm in the end of the eighth experiment cycle. On one side, the sulfide in the simulated industry-marine environment had a great impact on the pitting of the surface; on the other side, the sulfite ions penetrated into the grain boundary with the corrosive medium and promoted the intergranular corrosion. The analysis of mechanical properties showed that the elongation rate of the specimens reduced by 26% after eight cycles of testing in this environment, and the corresponding fracture mechanism changed from ductile fracture to cleavage fragile fracture caused by pitting and intergranular corrosion.