Dear Dr. Anas Ghailane ,

I suggest you to have a look at the similar question present on RG, available at: https://www.researchgate.net/post/Difference_between_corrosion_potential_and_corrosion_current_Which_is_more_detrimental_for_corrosion

In particular, I am in tune with Dr. Stefan Krakowiak's answer that corrosion current is a kinetic value whereas potential is thermodynamic value. From this concept, having a higher corrosion current value generates greater degradation.

My best regards, Pierluigi Traverso

Dear Anas Ghailane ;

In general, the coating with less corrosion current and higher corrosion potential has higher corrosion protection than the coating with a higher corrosion current and lower corrosion potential.

Subject the coatings to tests, e.g. in a salt chamber, a humidity chamber. Atmospheric corrosion resistance tests can also be performed. These tests will chart the corrosion resistance of your coatings.

jm

1.Generally in coatings high Ecorr and low icorr value indicates it has good stability, consumes less current, and has good resistance to corrosion.

2. Higher icorr means higher initial corrosion rate and low Ecorr means it is less stable and is more prone to corrosion

Do you really talk about the corrosion resistance of a coating? That´s only reasonable if you have deposited your coating on an inert substrate. Then you can discuss the corrosion resistance of a coating. It´s like in tribology: corrosion is a system property. Hence, the corrosion behavior depends on the coating, the substrate and the electrolyte. To get a better understanding of the corrosion behavior of coatings, one should deposit the coatings onto inert substrates. Then one has to perform electrochemical (polarization) tests of these samples and also of the uncoated substrate material. In the next step, one can deposit the coatings onto the substrate material of choice and also perform electrochemical tests. Then you can discuss the corrosion behavior. In general, for corrosion resistant coatings on less noble substrate materials (e.g. low alloyed steel) the defects in the coating govern the corrosion behavior.

br

Martin

Mr. Fenker makes a good point. At the end of the day its the impact on the substrate you wish to protect. Run corrosion tests by coating the substrate you are protecting, run corrosion tests. check for which provides better protection.

Dear Anas Ghailane,

High corrosion potentials are good for coating. If the corrosion potential is dropping, it means that the sample is oxidizing and negative charges are accumulating in it. Thus higher flame temperatures will lead to denser coatings and metallurgical.

Generally, most negative corrosion potential and the highest corrosion rate. The higher the Ac/Aa is, the greater will be the corrosion rate of the anode. Therefore shifting the corrosion potential of the metal substrate to lower values and hence it can decrease the corrosion rate.

In general, the decreasing is the corrosion resistance of metallic glasses; the increasing is the solution aggressiveness, especial for the chloride ion concentration. Unfortunately, the mechanism of pitting corrosion of metallic glass is not clear, as that of conventional materials such as stainless steel.

Ashish

Dear Anas,

Coated specimens have high value of corrosion resistance compared to UN-coated specimens. But current densities does not change that much, for the un-coated and coated specimens they may be same or below 1µA/Cm2. You can check this with EIS measurement in simulated aggressive environment.

Ashish.

well, it sounds like a conductive "noble" metal coating...