-- The Home Page of the Finishing Industry

on this site
current topics
Live! From beautiful Pine Beach New Jersey: Welcome to the world's most popular metal finishing website

topic 60717

Can red oxide under acidic conditions become a black oxide?

March 22, 2018

Q. I tested an oil sample that had shown red oxide as extreme, 9 on a scale of 0 - 9. It also had dark metallo-oxide as 0. In addition, this oil had an acid number of 1.8 per ASTM D974 [link by ed. to spec at TechStreet].
I took an additional sample of the same batch and sent it to a different lab for testing 4 weeks after the initial sample had been sent in. The new results were 5 out of 10 for black oxide, and red oxide 0. The AN went down to .374.
Is it possible that the small amount of acid in the oil turned the red oxide to black oxide, and became almost neutralized?

Richard Greenwald
Lubricant Sales - Beachwood, Ohio USA

If you have a question in mind which seems off topic, please Search the Site

ADD a Q, A, or Comment on THIS topic START an UNRELATED topicView CURRENT HOT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2019, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.