Corrosion Resistance of Cast Aluminium Bronzes Containing Chromium and Silicon Additions

Abstract

The corrosion resistance of aluminium bronze in the cast condition can be improved by additions of chromium and silicon. This has been shown by testing modified alloys in various aggressive environments. The chromium addition is effective in NaCl, H₂SO₄ and sea water, and when silicon is also added the resistance to HCl is improved. Heat treatment significantly affects the corrosion resistance, and slow cooling from 600°c is beneficial. Addition of chromium does not result in the γ₂ phase behaving anodically.

The modified alloys have high tensile strength and good ductility. It is suggested that they merit consideration for environments where attack by sea water, acid or neutral salts is a hazard.