Another Cadmium Problem
What is causing black spots to appear on the surface of a steel part that is cadmium-plated and then treated with a chemical conversion coating?
Q. We have an ongoing issue with a steel part that is cadmium-plated and then treated with a chemical conversion coating. After a period of time, black spots start to appear on the surface. What is causing this? –M.C.
A. As mentioned above, there are two probable causes for this problem: inadequate rinsing and a porous cadmium deposit. Your final rinse procedure following the plating step should be alternating cold and warm rinses, ending with a warm rinse.
Check your cyanide concentration and make changes to bring the concentration up to specifications.
RELATED CONTENT
-
Sizing Heating and Cooling Coils
Why is it important for you to know this?
-
Cleaning, Pretreatment to Meet Medical Specs ISO 13485 or FDA 21 CFR820
Maximilian Kessler from SurTec explains new practices for industrial parts cleaning, metal pretreatment and decorative electroplating in the medical device industry.
-
Smut and Desmutting
Question: I am new to this industry and have heard about smut and desmutting operations.