Post bake cadmium plate induced embrittlement

During post cad plate bake on several high strength steel parts (Hy-Tuff, 300M, and 4340M) the oven malfunctioned and the parts were baked for 3 hours ranging from 400F to 700F and for an additional 1 hour from 700F to 740F. I assume that there is a deep cadmium embrittlement. Are there any known ways to relieve these parts?

I have only been an observer on this site and was hoping it would stay that way, but I have to respond after seeing the steels you are dealing with.

In addition to probable solid metal embrittlement, you have overtempered these steels. They would have to be re-heat treated even if no plating was present.

The only way I could envision you could remove the cadmium is to remove the affected surface layer. However, I would have concern about the condition of the material, even with a cross-section to determine the extent of cadmium diffusion.

If I was asked to disposition these parts, they would be scrapped. Sorry about your situation.