Effect of Nitric Acid Concentration on Intergranular Corrosion of 5083-H116 Aluminum Alloy Plates

Intergranular corrosion test was carried out for 5083-H116 aluminium alloy plates with thickness of 6 mm in nitric acid solution with different concentrations. The susceptibility to intergranular corrosion of 5083-H116 aluminium alloy plates was evaluated by mass loss method. The results show that the tendency to intergranular corrosion became large with the decrease of nitric acid concentration for 5083-H116 aluminium alloy plates. When nitric acid was diluted to 51% of mass fraction, the mass loss could not meet the standard requirement of no larger than 15 mg/cm².