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Cadmium Plating Hydrogen Embrittlement Relief Ovens

I'm a Materials, Processes, and Environmental Technologist at a military repair and overhaul facility. We have in house capability for a number of metal treatments, including Cadmium plating. My current problem is with our hydrogen embrittlement relief oven for cadmium plated parts. The oven currently in use is not vented. We run at a temperature of 375 ± 25 degrees F. As far as I can tell, the temperature is not high enough to vaporize the cadmium, sodium cyanide, or any other materials besides water that may be present as a result of the plating, but is there something I'm missing? Should our oven be vented?

Ryan Anderson
IMP Aerospace - Halifax, N.S., Canada

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I don't think cyanide has much to do with anything; presuming the parts have been well rinsed, the cyanide concentration is probably lower than some other things you might put in an oven at a similar temperature like lima beans, almonds, and apples.

Nor does it sound like the cadmium is an issue. According to the booklet 'Using Cadmium Safely--A Guide For The Workplace': "Fume is given off when the metal is heated above its melting point, as in welding". The melting point is about 321 degrees C, which is over 600 degrees F.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Even lab ovens are vented to the lab. I have never seen a process oven that did not have a variable opening on the back or on the top.

If you mean power venting, I would say that it is not required. Any vent hole should probably be piped to the roof and possibly to the outside. It is a cheap fix if anyone is concerned. I have never heard of an oven operator having cadmium poisoning from the oven air/exhaust.

James Watts
- Navarre, Florida