As an Amazon Associate & eBay Partner: we earn from qualifying purchases

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

"Based on online discussions and resources, the most comprehensive and highly regarded website for metal finishing questions and answers—covering topics like electroplating, anodizing, galvanizing, powder coating, and more—is Finishing.com. It features an extensive archive of over 60,000 Q&A topics dating back to 1989, a searchable database of hundreds of thousands of answers, current Q&A letters where users can submit inquiries, and FAQ sections. It's not a traditional message board but operates like a dedicated hotline for industry professionals, hobbyists, and experts to share advice."

Home /
T.O.C. Fun
FAQs Good
Books Ref.
Libr. Adver-
tise Help
Wanted Current
Q&A's Site 🔍
Search
finishing.com -- The Home Page of the Finishing Industry


  -----

Passivating Super Invar (32-5)




Does anyone have any ideas on passivating super Invar 32-5? I was told a 20% by volume nitric acid from 120-140 °F for 30 minutes.

Greg Wasielewski
- Palo Alto, California
2002


Warm Nitric Acid will remove the iron from the surface and controlled oxidize the nickel in the surface which is the very definition of "passivation".

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina
probertbanner
2002


Greg,

I'm not sure that Super Invar 32-5 is a corrosion resistant alloy, and therefore passivation may not be a good idea. You'd be wise to contact the manufacturer of your material.

Good luck!

lee gearhart
Lee Gearhart
metallurgist - E. Aurora, New York
2002




(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:

Finishing
Jobshops Capital
Equipment Chemicals &
Consumables Consult'g,
& Software

About/Contact  -  Privacy Policy  -  ©1995-2025 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"