Fastening Zinc Plated Steel to Aluminum (6000 Series)

[Sai Bhargav]

Hi, I am trying to determine the severity of Galv. corrosion on 1" wide X 1/8" thick Zinc plated spring steel fastened into a 1" x 3/4" 6005A-T61 alloy tube. These materials will not be exposed to harsh environments, mostly indoors.

1. Is this dissimilar metals connection is acceptable?
2. Are there any standard corrosion test methods to validate the connection?
3. Will the zinc plating on the steel helps to avoid corrosion between steel & Aluminum?
4. Any recommendations to fasten these two dissimilar metals together?

Thank you.

 

[3DDave]

Look at the electromotive gap between aluminum and zinc. For example:

https://www.hoseandfittingsetc.com/technical-info/galvanic-corrosion

 

[EdStainless]

On the whole there are no real issues.
But I have mixed feelings (and track record) with Zn coated springs.
The Zn is there as a sacrificial coating to protect the steel. But in order to do that the Zn has to corrode. When it does hydrogen is generated. Spring steels are usually high strength and highly stressed. When that steel absorbs hydrogen it becomes very brittle.
The Zn will slow down corrosion between the steel and Al.
How are you planning on fastening these together?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

 

[Sai Bhargav]

Thinking to use SS fastener to join Aluminum & Zinc plated spring steel.