Corrosion Resistance to Acids and Alkalis

Cobalt-based alloys are generally resistant to corrosion in aqueous environments. Cobalt-based alloys are very susceptible to corrosion in phosphoric acid, but are resistant to corrosion in acetic acid environments. The corrosion resistance of cobalt-based alloys is improved in sulfuric acid environments when oxidizing agents are present. Cobalt-based alloys are typically more resistant to nitric acid, but more susceptible to corrosion in caustic environments than their nickel counterparts.