Galvanic compatibility 1

[LouV]

I have a unit whose enclosure is 6061 aluminum with chem film per Mil-C-5541-3 on the exterior. On installation, this enclosure engages two 300 series stainless steel pins (passivated). Does the chem film, although conductive, provide a barrier to corrosion in humid environments between the stainless steel and aluminum or do I risk corrosion? The anode-to-cathode area ratio is large. The connection between the stainless and aluminum provides a bonding ground for the unit so the interface must remain conductive.

 

[swall]

The chromate conversion coating,if conductive, will allow for galvanic contact, as you have surmised. With a small cathode and large anode, it may not be that bad.Depends on the corrosive environment.