Susceptibility to pitting corrosion of 6056 aluminium alloy

The susceptibility to pitting corrosion of the 6056 alloy was studied and compared to that of the 2024 alloy. The 6056 alloy was more resistant to pitting than the 2024 alloy for high choride ion concentrations but less resistant for low chloride. Moreover, the variation of the susceptibility to pitting of the 6056 alloy with the potential was similar to that of pure aluminium, unlike the 2024 alloy which presented a peak of susceptibility to pitting. This difference was related to the behaviour of the coarse particles in the alloys. Because of this, the 6056 alloy appears more suitable than the 2024 alloy in conditions where pits can appear.