Copper Stainless Steel Reaction

I wish to use hard copper elbows to join aluminum tube frame members.

Copper stainless steel reaction. The elbows must be permanently joined to one frame member at each knock down joint. Galvanic corrosion can be controlled by the use of sacrificial anodes isolation of the metals from electrical continuance protective plastic coatings or epoxy coatings or with corrosion inhibitors. Lead and copper are quite close on the nobility table to stainless steel and so the bimetallic corrosion risks should be small. However mixing these metals is not generally advised due to the potential for sudden pipe corrosion and discolored water.

In the copper stainless steel couple the open circuit potential of stainless steel was found to play a decisive role. Iron and steel are generally not a problem unless their mass is similar or smaller than that of the copper. It is not necessary to isolate copper from lead tin or stainless steel under most circumstances. There are three commonly used metals for potable water plumbing pipes including stainless steel copper and brass.

Any corrosion product if washed onto stainless steel may however result in problems not associated with the bi metallic effect and so not be predicted from the tables. These metals are used because of their durability and long lifespans. In addition the area ratio of stainless steel to copper altered copper corrosion behavior. Corrosion issues with aluminum copper and stainless steel 2004.

In most cases when stainless steel was in the passive state and acted as the cathode the contact accelerated copper corrosion.