Corrosion after passivation process

[Ramachan]

Guys,
Any expert can assist me to overcome this problem.
I'm dealing with medical component in where after machining process, the component need to be cleaned from oil & dirt then went for passivation process.
every time I will have a small quantity (after passivation) which is contaminated or yellow stain similar to rust.
What I need to do differently to overcome this problem.

 

[bimr]

Impossible to say with the little information provided. The ultimate choice of passivation method will depend on the acceptance criteria imposed by your customer.

http://www.electrohio.com/Finishing/Passivation/Passivation.htm