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Active Contributor

Join Date: Mar 2010
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Copper Plate on Mild Steel Base Stud Facing Discoloration

08/25/2016 5:00 AM

Hi Guys,

i am facing a problem where after entering powder coating curing process (temperature 180 degree Celsius to 220 degree Celsius), my mild steel base stud wild copper plating facing discoloration. refer figure below. Any guys know what is the root cause and how to solve this issue?Thanks

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Guru

Join Date: Oct 2008
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#1

Re: Copper Plate on Mild Steel Base Stud Facing Discoloration

08/25/2016 9:43 AM

Looks like the welding heat caused it.

Change the process.

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Guru

Join Date: Mar 2007
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#2

Re: Copper Plate on Mild Steel Base Stud Facing Discoloration

08/25/2016 10:13 AM

You might try a chelating agent such as Benzotriazole with the copper plating or possibly a high temperature coating such as Tediar...I would speak with an expert in this area for recommendations, you may need to try a few different approaches....

https://www.copper.org/resources/properties/protection/clear_finishes.html

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Guru

Join Date: Mar 2007
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#3

Re: Copper Plate on Mild Steel Base Stud Facing Discoloration

08/25/2016 11:28 AM

You could install the copper plated bolts after the powder coating curing process, and instead of welding them in you could use a nut on one side....or epoxy them in with an industrial strength formula...

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Power-User

Join Date: Nov 2015
Posts: 335
#4

Re: Copper Plate on Mild Steel Base Stud Facing Discoloration

08/25/2016 11:34 AM

try replacing the copper with steel just for the sake of trial and see what happens.

If no discoloration happens, it must be that your process temperature reached the activation temperature for copper and mild steel to react, dissimilar metals inhibits rapid corrosion, usually.

And thank you for your problem.

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Participant

Join Date: Sep 2016
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#6
In reply to #4

Re: Copper Plate on Mild Steel Base Stud Facing Discoloration

09/16/2016 9:51 AM
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Guru
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#5

Re: Copper Plate on Mild Steel Base Stud Facing Discoloration

08/25/2016 1:33 PM

I don't know the answer. Is that supposed to be copper-colored. If I entered a curing process 180-200 C, I would be red-faced too. Usually, though, I just go to a bar and sheite-faced after such an event.

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