No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

Too much passivating




2007

Hi Everyone,

We are starting a passivation line to finish the assemblies we build here. Each requires passivation prior to assembly and then again after welding is complete.
My question is, why is it necessary to passivate the pieces prior to welding and assembly? The whole assembly is 321 stainless. Any ideas would be helpful.

Micheline Forth
Finishing Company - Savannah, GA, USA



Cleaning of the weld area and at least 1/2" on each side (more for thick sections) avoids weld contamination. In addition to precleaning to remove organics, pickling or mechanically cleaning of stainless steels to remove any heat treatment oxide, carbon steel or embrittling elements such as zinc, lead, sulfur, cadmium, etc., is advised. The Welding Handbook (p. 79 in Vol. 4 of the 7th Edn.) specifically mentions pickling with a nitric acid solution as an acceptable method. Check American Welding Society or ASME guidelines or codes that may apply for your product.

Ken Vlach [deceased]
- Goleta, California

contributor of the year Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.

2007


none
www.finishing.com is made possible by supporting advertisers ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages



(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:

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


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"