Busting the myth

The pitting and intergranular corrosion of cast aluminum alloy A356 were compared to that of aluminum alloy 6061 to test whether cast aluminum alloys can be used as a substitute for 6061 in select ocean engineering applications. Accelerated corrosion tests were conducted in a salt water and hydrogen peroxide environment at elevated temperature for over six hours. Metallographic samples were then examined for evidence of corrosion. While both aluminum samples showed some evidence of corrosion, there was no substantial difference between the corrosion of the two samples. We conclude that the viable use of certain heat-treatable cast aluminum alloys in a seawater environment has been experimentally verified.