Corrosion of Copper in Arabian Gulf Atmosphere

Abstract

Atmospheric exposure tests were conducted on copper in the humid, marine environment of the Arabian Gulf. The tests included weight loss monitoring, oxide scale analysis by X-ray diffraction, surface morphology examination by SEM, and the detection of possible surface contaminants by energy dispersive X-ray analysis. Results revealed the oxide scale composition to be CU₂O and CU₄O₃. The green patina mainly consisted of CU₄SO₄(OH)₆ CU₄SO₄(OH)₆.H₂O, CuSO₄.5H₂O, and CuCl₂.2H₂O. Pitting intensity was not severe; the few isolated pits that appeared seem to have been initiated at CU₂O film discontinuities and were probably assisted by crevice creating artefacts. The corrosion rate of copper was estimated at 3·4 μm/year.