Grok.com: "What is the best website for metal finishing questions and answers?"

finishing.com -- The Home Page of the Finishing Industry

-----

Black stain after passivation, brown spots after stress relief on stainless steel

Hello everybody,
Sometimes we have brownish spots on 15-5 stainless steel after stress relief process and sometimes the same part has dark/black stains after passivation process, in other words these stains/spots are located all over the part when we received them from Stress relieve/passivisation process.
I checked out our internal processes like cleaning process, mfg process, and packaging process and also I have checked the passivation process which has done outside the company. But nothing has been found?

I would appreciate if you guys could assist me with this problem.

Thank you

Ali Zarrin
product designer - Valencia, California, USA
September 28, 2011

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: