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Tafel plot LPR – Corrosion – Application Note 10

Latest updated: May 6, 2020


The characterization of a corrosion system depends on the determination of cathodic and anodic Tafel parameters (βc, βa) and the corrosion rate. The measurement of these parameters are mainly determined using the Linear Polarization (LPT) and Tafel Plot (TP) techniques available in EC-Lab software.

In this note, iron in acidic media was characterized as a tafelian system. The corrosion parameters were determined using Stern (TP) and stern and Geary (LPT) methods. The corrosion rate value was obtained with Tafel Fit was compared to that obtained with Rp Fit.



The corrosion current is a typical corrosion value which can be related, for example, to the corrosion rate. The information obtained from both values is necessary when studying the corrosion state of a given system. The aim of this tutorial is to demonstrate to the user how to determine the corrosion current using simple graphic tools on EC-Lab linked to the Tafel equation: Tafel fit and Rp fit.



  • Working electrode: RDE (Rotating Disk Electrode) of iron, working area: 0.0314 cm2, electrode rotation speed: Ω = 800 rpm (rotations per minute).
  • Counter electrode: Platinum wire
  • Reference electrode: Saturated Calomel Electrode (SCE)
  • Solution: HCl (0.1 M)


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