Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site

Chime right in! (no registration req'd)

-----

"SUS303 is rusting in 2 weeks"



 

We have been machining some SUS 303 parts, which under normal conditions should not rust. But recently we had been seeing some of our parts with some brownish stains which resemble rust, after about 1 to 2 weeks. We are using a CNC with water based coolant for machining. Any reason for the parts to turn out like this?

Padmavathy Subbrayan
- Penang, Malaysia
^


 

Mr. Subbrayan:

What you are seeing COULD be rust, but it is probably sulfides and sulfates from the sulfur in the 303. You can tell which it is by testing in a 5% NaOH solution overnight (it probably will take only an hour or two). If the yellow stains go away, it was sulfur caused. If they do not go away, soak the parts in a citric acid based product (contact us if you need this). If the discoloration goes away, it was rust. Let us know if we can help.

lee kremer
lee kremer sig
Lee Kremer
Stellar Solutions, Inc.
supporting advertiser
McHenry, Illinois

stellar solutions banner
^


July 9, 2010

Hi Mr Lee kremer,

You mention that SUS 303 soaked in citric acid based product can remove rust. I would like to know how long do we need to soak?

Regards
Dexter

Dexter Ng
- Singapore
^


July 9, 2010

Dexter,
It depends on the severity of the rust and the temperature of the citric acid bath. As with what Lee said about the NaOH bath removing sulfur, it could be an hour or two to overnight.

ray kremer
Ray Kremer
Stellar Solutions, Inc.
supporting advertiser
McHenry, Illinois
stellar solutions banner
^

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

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start 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    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA