Where the
world gathers for metal finishing
Q&As since 1989


-----

How to do Pickling solution analysis

Q. I am interested in technical books that describe the process of titrating nitric/HF acid pickling solutions to determine percentage of Nitric, HF and iron or titanium content.
The information should include a list of chemicals, equipment necessary to perform the analysis, the titration procedure, including any equations required to determine the % composition.

I would also like to have information on how much Nitric Acid/HF should be added to a tank on known volume to bring the tank up to specification requirements, once the analysis is complete.

Thanks in advance for your answer. I am reviewing our present process to perform this analysis.
Not being a chemist, I would like some starting point to know if our present process will yield accurate results.

Frank Reyes
metal bellows - Anaheim, California
2003

---

2005

Q. Hi There

Question stated above, I would also be interested in any applicable information.
My main objective is to obtain the procedure to analyze for iron & titanium content in a pickle solution of;
40-47% Nitric
2-4% Ammonium Bifluoride
Balance DI water

We use the solution for specific etching prior to penetrant inspection, & for a post shot peen cleaning operation.
Also thank you in advance,

Grant Crawford
Aerospace - Kitchener, Ontario, Canada

---

---

How to know if a pickling solution is still usable?

Q. Can anybody help me how can I decide if a liquid for pickling (mainly HF and H3PO4) is still good enough for using? So for which parameters should I measure (besides examining the quality of the treated metal)? I mean if I used it once and I'd like to use it again, which parameters guarantee the same quality?

Thank you for your kindness!

Anita Zatonyi
- Budapest, Hungary
August 8, 2014