Effects of Na₂S₂O₃ Concentration and Solution Temperature on Anti-corrosion Property of 6061 Aluminum Alloy in Marine Environment

The corrosion resistance of 6061 aluminum alloy at various Na₂S₂O₃ concentrations and solution temperatures was studied in simulated seawater by using a series of tests. The results reveal that adding Na₂S₂O₃ promotes the repair of passivation film, which improves its stability, compactness and integrity. As Na₂S₂O₃ concentration increases, a decrease in corrosion rate and pitting depth/width is presented, and the pit corrosion degree significantly declines. With the rising solution temperature, the amount of AlFeSi precipitated phase reduces, and the corrosion form evolution of 6061 alloy from slight pitting to ulcerative corrosion pit.