CORROSION AND CORROSION-FATIGUE RESISTANCE OF A MODIFIED ALUMINUM-MAGNESIUM ALLOY IN ARABIAN-GULF SEAWATER ENVIRONMENT

The effect of chromium content on the corrosion and corrosion fatigue behavior of modified Al-Mg alloy in Arabian Gulf water has been studie d. Addition of 0.1% chromium is found to have a beneficial effect on t he corrosion and corrosion fatigue resistance of modified Al-5454-H34 alloy. A further increase in chromium content from 0.1 to 0.3 results in a degradation of corrosion and corrosion fatigue resistance of the alloy. It is suggested that the lowering of the corrosion and corrosio n fatigue resistance of the alloy containing the higher chromium conte nt (0.3 wt% Cr) in H34 temper condition may be due to the segregation of secondary phases at the grain boundaries, which weakens the protect ive oxide film and lowers the corrosion and corrosion fatigue resistan ce of the alloy.