Plating in Corrosive Atmospheres

[gordonl]

I'm interested in hearing the experience of others with types of plating used in SO2 enviroments, (IE tin vs. silver) as well as other types of protection used.

 

[DougMSOE]

You say SO2 environment, what is the exact application?
There are several different ways to approach this.

 

[gordonl]

The application pertains to the control and distribution in and around a blast furnace. I would think it would be similar to a smelter area.

Currently we use tin as much as possible, but recently the field maint had 600V breakers rebuilt with silver plating, which I know is more susceptable to Sulphur. I'm looking at replacing the stationary part of the breaker disconnects with tin plating. The manufacturer is going to test the temperature rise of this combination.

 

[DougMSOE]

I would suggest you also try AgCdO (silver cadmium oxide). This has proven very long life in forges and foundries.
Hope this helps.

 

[RajT]

A switgear manuf would recommend tin plating rather then silver, aside lower cost, a thicker plating can be applied with tin compared to silver thus providing better protection against corrosion.
Note that both silver and tin have equally comparable properties on corrosion resistance.

 

[DougMSOE]

My only problem with tin is that tin oxides ar an insulator for thermal as well as electrical. Maybe it will work for you.