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Red rust on nickel-brass plated mild steel screws
I am from India and I would like to know how we can prevent RED RUST on Brass Plated Mild Steel Screws?
After brass plating on mild steel screws has been done they look very bright and yellowish like brass.
But after we assemble them into our Brass Terminals and Ship them to our buyers the screws catches RED RUST.
We investigated with the plater but even after a good copper + nickel base on mild steel screws proir to brass plating these screws catches RED RUST.
I shell request you to please guide me how we can prevent this red rust ?
Is there any Lacquer or chemical process after brass plating with the help of which we can prevent these screws getting red rust ?
Await for your answer
Mr Virat Rabadia
brass works - Jamnagar, Gujarat, India
It sounds to me like you have a classic case of brass dezincifciation. This is quite common in brass parts in some water supplies and is caused by the water dissolving out the zinc from the brass to leave a copper matrix or sponge. This sponge has no strength and can easily fall apart. I therefore suspect the brass plated screws are being exposed to alkaline conditions that allow the zinc to be dissolved.
Perhaps you could comment on when this "red rust" appears and how the parts are stored?
R&D practical scientist
Chesham, Bucks, UK