Effect of hot rolling on corrosion resistance of Cu-7Ni-3Al-1Fe-1Mn-0.02Sm alloy

Improving the corrosion resistance of copper-nickel alloy is crucial to extend its service life in marine engineering. In this study, hot rolling was used to improve the corrosion resistance of the alloy, and the reasons for the improvement of corrosion resistance were explored. The corrosion rate of the alloy was reduced by 89% from 0.0150 mm/a to 0.0017 mm/a when the deformation amount is 80%. The improved corrosion resistance can be attributed to two reasons: (1) hot rolling promotes the formation of dense Cu₂O film in the corrosion product, reduces the content of loose Cu₂(OH)₃Cl, making the corrosion product film more compact, (2) Fe, Ni and Sm elements involved in the formation of the corrosion product film, generated Sm-S phase, γ-FeOOH and Ni(OH)₂, making the corrosion potential shift positively. This work proposes an alternative approach to enhance the corrosion resistance of copper alloys.