Corrosion Of Copper In Sea Water Research Articles

Imidazole based compounds as copper corrosion inhibitors in seawater

The effects of imidazole and its structural derivatives: purine, adenine and 6-benzylaminopurine, on copper corrosion in seawater were investigated. Electrochemical methods were chosen for this purpose and the results show that they all act as mixed-type corrosion inhibitors under tested conditions. According to the potentiodynamic polarization results inhibition efficiency at corrosion potential increases in the following order imidazole<purine<adenine<6-benzylaminopurine, which is in agreement with the expectation that the increase of molecular weight and number of heteroatoms in the molecule leads to the increase of inhibition efficiency degree. In the broader potential range, adenine is more efficient. The mechanism of inhibitor action includes adsorption on copper surface that fits the Langmuir adsorption isotherm. Quantum mechanical calculations indicate that there is a correlation between energy gap and inhibition efficiency.

Effects of rotating electromagnetic on flow corrosion of copper in seawater

The flow corrosion of copper in seawater was investigated with the rotating electromagnetic corrosion experimental bench for 12 d. Scanning electron microscopy equipped with EDAX and X-ray diffraction (XRD) were used for the analysis of surface microstructure and phase composition of samples. The results indicate that the composition of Cu 2O and CuO is created in corrosion products film after drying in the air, and the flow corrosion process can be successively defined as uniform pitting corrosion, expansion, formation of corrosion film, solution of surface products and pitting corrosion. Corrosion inhibition of copper during flow corrosion can be significantly improved with rotating electromagnetic field in the seawater.

Corrosion of copper in seawater and its aerosols in a tropical island

A complete characterization of copper corrosion behavior has been carried out under permanent immersion, water line, splash zone and at the atmosphere (near and far from the sea) at the tropical Cuban archipelago. No significant differences have been determined for corrosion of copper under complete immersion for test sites representative of Cuban archipelago. The maximum corrosion rate was observed on the line of water, related to the partial removing of the corrosion products layer due to water movement (waves) and a higher availability of oxygen. Patina composition was characterized using XRD, IR, EDS and SEM techniques. Paratacamite (Cu 2(OH) 3Cl) was the main component of the patina formed under complete immersion, on the line of water and in the splash zone. In poorly polluted atmospheric marine environments also atacamite (another structural modification of Cu 2(OH) 3Cl) was found. When environmental SO 2 reaches a competitive level with the chloride aerosol the patina formed is a complex mixture of basic cupric chlorides (paratacamite and atacamite) and basic cupric sulfates, antlerite (Cu 3(SO 4)(OH) 4) and brochantite (Cu 4(SO 4)(OH) 6). Brochantite and basic cupric chlorides are detected at inland rural sites. The patina morphology reveals details about the local environment in which it is formed and shed light on its more or less protective role for the metal. The relatively large corrosion rate under complete immersion and on the line of water is related to the formation of a patina with poor adherence to the metal surface and to a porous layer of cuprite formed by relatively large octahedral crystals.