Neutral salt spray tests on Fe–Al and Fe–Al–X

The corrosion resistance of Fe–Al and Fe–Al–X alloys under neutral salt spray conditions has been evaluated. For the binary alloys the corrosion resistance constantly improved up to an Al content of about 30 at.%. While higher Al contents did not better the corrosion resistance it may be further improved by addition of passivity-inducing elements. The phases that formed on the various alloys have been identified. Particularly small weight losses after neutral salt spray testing were observed for those alloys where thin and dense layers of Fe3O4 (magnetite) had formed on the surfaces during the tests.

► Corrosion behaviour of Fe–Al and Fe–Al–X under neutral salt spray conditions.
► Corrosion resistance increases with increasing Al content up to about 30 at.% Al.
► Fe–Al alloys show improved corrosion resistance compared to mild steels.
► Passivating elements yield corrosion resistance comparable to stainless steels.