Galvanic corrosion of AA5052/304SS welded joint with Zn-based filler metal in marine engineering

Galvanic corrosion and localized corrosion behavior of AA5052/weld seam/304SS tri-metallic couples were examined by EIS, ZRE, SKP and SVET tests after tungsten inert gas (TIG) arc welding. The results showed that the weld seam had a relatively high corrosion susceptibility. The asymmetric corrosion of weld seam was attributed to the macro-galvanic effect between the weld seam/AA and the weld seam/SS. Localized corrosion of Zn in delta-FeZn10 induced the corrosion trenches and channels initiation. The deep corrosion propagation at the weld seam/SS interface was brought on by local acidity and micro-galvanic effect.

Automated summary

The galvanic corrosion and localized corrosion behavior of AA5052/weld seam/304SS tri-metallic couples were investigated using various tests after TIG arc welding. The results showed that the weld seam is susceptible to corrosion. The asymmetric corrosion of the weld seam is attributed to the macro-galvanic effect between the weld seam/AA and the weld seam/SS. The localized corrosion of Zn in delta-FeZn10 resulted in the initiation of corrosion trenches and channels. The deep corrosion propagation at the weld seam/SS interface was caused by local acidity and micro-galvanic effect.