Effect of the heat treatment on the behaviour of the corrosion and passivation of 3003 aluminium alloy in synthetic solution

The corrosion and passivation of 3003 aluminium alloy in synthetic solution similar to industrial water at pH = 8.2 were studied by electrochemical techniques. The effect of the following factors on the dissolution and passivation of this alloy are discussed: heat treatment, pH solution, temperature of medium and chloride ions. Surface analysis was investigated by X-ray analysis (EDS) and scanning electron microscope (SEM). Heat treatment was carried out during 2h at temperatures varying between 350 and 550°C. Potentiodynamic polarization result showed that the corrosion behaviour is performed for treated sample at 450°C. The ability of pitting corrosion increases with the elevation of chloride concentration and the uniform corrosion is affected by the temperature of corrosive medium.