Atmospheric corrosion behaviors of 6000-series aluminum alloy under tropical climate influences of Thailand

Abstract The current research was aimed to investigate atmospheric corrosion behaviors of 6005A and 6082 aluminum alloys for a certain application in high-speed railway employed for service in Thailand. Actual exposure atmospheric test with the maximum period of 18 months was conducted at urban and marine–coastal environments. After completion of actual exposure test, corrosion behaviors of the uncoated alloys were determined based on corrosion mass loss and pitting corrosion aspects. It turned out that remarkable corrosion severity found at marine–coastal environment with respect to urban environment was attributed to higher deposition rates of cumulative chloride (around 1331 mg m−2 day−1) and sulfur dioxide (around 200 mg m−2 day−1) together with higher levels of RH (>80%) for the entire year of exposure. The alloys exposed at marine–coastal environment for 18 months long revealed the corrosion mass loss of approximately 2 g m−2, average pit depth of greater than 80 μm, and density of around 3 pits⋅cm−2.