Home /
Search 🔍
the Site

World's #1 finishing resource since 1989
No login needed: Chime right in

topic 59702

Can citric acid solution cause hydrogen embrittlement?

September 18, 2014

Q. For high strength steel springs (Rockwell C of 40) would a 2% solution of citric acid measuring a pH of 6 cause hydrogen embrittlement? The intention is to use this solution for polishing.

Michael Formberg
- Chardon, Ohio USA

meher baba courtesy of Wikipedia
September 22, 2014

A. Please take a look at the discussions on Letter 1216 et seq. and particularly my response of 11/26/13. For there to be unrelieved hydrogen embrittlement, there needs to be some sealing of the hydrogen into the steel. Since there is not in your case, any hydrogen will self-relieve. Besides, citric acid is a very weak acid and the amount of hydrogen will be very small. As Bobby McFerrin said (from Meher Baba) "Don't Worry, Be Happy."

Tom Rochester
Plating Systems & Technologies, Inc.  
supporting advertiser
Jackson, Michigan, USA
plating systems & technologies banner ad

September 24, 2014

A. I have no specific information on hydrogen embrittlement with citric acid but I am inclined to go with Tom.

But I do have an observation on pH. I am a little surprised to find 2% citric acid giving a pH of 6. I have seen DI water near that. From a quick back of envelope/guess, I would expect to find a pH in the range of about 2 - 3.

How do you measure pH?

geoff smith
Geoff Smith
Hampshire, England

affil. link
pH Paper

October 20, 2014

Q. Thank you Tom! That discussion is very interesting and seems to pertain to my situation. Appreciate the feedback.

Geoff - To check the pH I used test strips from Hydrion. The citric acid had a pH of 3-4 before diluting with water. Once diluted with water to a 2% solution it had a pH of 6.

Michael Formberg
- Chardon, Ohio USA

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:

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA