During electrochemical corrosion tests, we know that Open-circuit potential (OCP) and Electrochemical impedance spectroscopy (EIS) are non - destructive tests, while potentiodymanmic polarization is a destructive one. Can we performed the tests in the following sequence OCP, EIS, and PDP without changing the metal sample and corrosive solution?
Dear Dr. Anees Abdullah Khadom ,
in reference to your interesting question, I suggest you to have a look at the previous, similar question on RG at: https://www.researchgate.net/post/For_corrosion_study_EIS_and_Tafel_can_be_done_on_same_sample_of_need_clone_for_it_if_one_side_of_sample_is_coated_then_weight_loss_method_is_valid
and at the following interesting article, where “…the experimental results showed that a stable open-circuit potential can be obtained in 30min, and then EIS and PDP tests were performed sequentially under this condition….”:
-Sunflower Head Pectin with Different Molecular Weights asPromising Green Corrosion Inhibitors of Carbon Steel inHydrochloric Acid Solution
Xuemei Ma, Jingbao Wang, Jingjing Xu, Jing Jing, Jun Li, Hailin Zhu, Siyuan Yu, and Zhiyong Hu
ACS Omega, 4, 21148−21160 (2019) Available at: https://pubs.acs.org/doi/pdf/10.1021/acsomega.9b02570
There are other researchers who prefer to do the tests strictly with separate samples because they believe that the results of the EIS and PDP tests are more comparable and reproducible ...; everyone has their own school of thought, trying, however, is not a problem, on the contrary, the time and costs of experimentation could be greatly reduced.
My best regards, Pierluigi Traverso
Dear Anees Abdullah Khadom,
Yes, you can perform this experiments in one cell with same material. But, use large cell volume, minimum 200 cm3, separate compartment for counter electode separated by glass frit, expecialy for Pt in NaCl, becouse during chatodic scan on platinum OCl- is formed which can disturb measurements. Also according to ASTM standard (I can send you? ) Eocp should be measured 55 minutes.
Best regards
Branimir
Thank you Branimir N. Grgur , I will be very thankful for sending the ASTM standard
OCP is a non-destructive test that just tell us about the stability of the system. And it is very important to measure other corrosion techniques such as EIS, LPR and potentiodynamic curves etc. at stable OCP. EIS is also a non-destructive corrosion measurement and polarization curves can be measured after EIS measurement. Researchers working on bio-corrosion run experiment for different immersion times (3, 7, 10 and 14 days), where they use the same sequence as you mentioned, measuring OCP and EIS everyday and then perform the potentiodynamic polarization curves in the end of the experiment.
Regard Khan
Hello,
My suggestion is also you can do all three experiments in a sequence. Nevertheless, think about how much time you spend on EIS prior to the PDP. If you are testing different samples, you may run PDP after different time intervals. That will lead to different immersion times prior to PDP. Make sure that you are running your experiments in the same conditions.
The non-destructive electrochemical tests:
EIS(electrochemical impedance spectroscopy) ,ECN( electrochemical noise) , LPR(linear polarization resistance)
Yes, you can do the tests this way:
1.OCP 2.EIS 3.PDPT
Hello:
Effectively, the two first techniques are non-destructive, but I think that you have to change the last. I suggest that you carry out the LPR in a short range of voltage at the end. Be careful with the conditions, and especially you should be sure that it is always working in the steady-state and that the conditions do not change a lot during the time ( since you could wait for 2 hours or more to realize all the techniques).
Good luck, and let us know how it worked.
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