Stainless Aluminum Galvanic Corrosion: A Smart Check

Summary for stainless aluminum galvanic corrosion Discussion

Stainless compatibility with trivalent CCC on aluminum casting is questioned in a salt fog test where a stainless part is press-fit into a trivalent chromate conversion coated aluminum die casting with very tight tolerances. Matt Byrne asked whether the attack he saw was truly galvanic corrosion and, if so, what the mechanism would be. Ted replied that he would doubt galvanic corrosion because stainless is far more noble than aluminum, implying the stainless/aluminum couple is not the likely explanation. After that, Matt said he would also investigate crevice-type pitting corrosion, which fits the tight press-fit geometry and restricted solution access. The thread does not reach a final diagnosis, but it points readers toward crevice corrosion or pitting as a more plausible cause than galvanic attack.