Electrolatic Corrosion?

[steve000]

Hi all.

Im currently rebuilding an Internal Combustion Petrol Engine. I am wandering, The Exhaust manifold Nuts and studs had become very rusted and where a real pain to remove. I am wandering Will i get problems with accelerated corrision, being dissimular metals interacting with each other if i use Stainless Steel Studs and nuts/or stainless studs and copper nuts, When Fixed into a Cast Steel Engine block?

If so, Is there any way of preventing this?

Thanks for any light anybody can shed

Steve

 

[Carburize]

I think you mean galvanic corrosion due to the connection of a more noble (more corrosion resistant) material.
Generally the galvanic couple tends to cause the less noble material to corrode more rapidly but the effect is dependent on the surface area of the two materials and a small area of noble material connected to a large area of less noble material is not particularly problematic. The process also needs corrosion taking place and a cell being set up.
In the engine case you describe the problem is much more to do with high temerature oxidation and the baking out of any thread lubricants.