area correlation aluminium/steel galvanic corrosion

[fitibomba]

Hi!

I would like to joint these two different metals (aluminium + carbon steel)

I know for advance that if the area of the anode is larger than the cathod they can corrode at the same rate.

But what is the correlation of areas? How higher should be the area of aluminium compared to steel?

Thanks

 

[mrfailure]

I think you are asking the wrong question. Being a galvanic couple, I would expect aluminum (in this instance) to corrode and no corrosion of the steel. You should look at methods (such as cathodic protection) to prevent galvanic corrosion.

Aaron Tanzer

http://www.lehightesting.com

 

[fitibomba]

Yes aluminium will corrode first but when it creates the protective oxide layer I think steel will loose more weight.

The thing I would like to know is if there is any correlation between the weight loss of steel and aluminium.

 

[Metaljon]

Just insulate the two materials so there is no electrical contact. Ideally the anode needs to be as large as possible if the metals are in direct contact. Probably not practical in your case so use a rubber gasket or similar.

http://nz.linkedin.com/pub/jonathan-smith/39/25/589