Aluminum 5052 has good corrosion resistance -- so purpose of anodizing it?

A. Proper anodizing may greatly improve its corrosion resistance.

Al 5052 often severely corrodes due to magnesium segregation into the grain boundaries of the alloy [5052 contains ~2.5 wt% Mg whereas the solubility limit of Mg in Al is < 1% at room temperature]. The stabilizing heat treatment used for commonly available tempers such as H34 & H36 contributes to the problem. Unless anodizing, for better corrosion resistance, use the H114 temper and avoid ever getting it much hotter than 100 °F.

Clean a sample of your 5052 and leave it in tap water. If there is excessive segregation in the alloy, 'cauliflower' corrosion nodules may sprout within a day or two.

Hi Ninganray. H32 is Strain hardened and stabilized by low temperature heating, 1/4 hard. As Ken alludes to, H114 involves strain hardening but no thermal treatment. When there are 3 digits after the H, it is a special variation often applicable to one particular shape or method.

Please try to put the question into the context of your own situation, as abstract questions have no direction to them. Thanks.

Regards,