SYMPOSIA PAPER Published: 01 January 1985
STP33773S

Current Versus Voltage Hysteresis: Effect on Electrometric Monitoring of Corrosion

Source

Potential-controlled polarization methods can cause large positive shifts of the breakdown potential because of induction effect. The latter gives rise to current hysteresis, which leads to large unpredictable charge densities, which leads to poor accuracy and precision in determining the protection potential Eprot. Galvanostaircase polarization (GSCP) prevents induction effect and current hysteresis; however, it is subject to voltage hysteresis, which could make the determination of Eprot difficult if not impossible. Fortunately, voltage hysteresis can be avoided easily by staying at low current levels and charge densities.

Hysteresis caused by slow electrode kinetics can give erroneous results in the cyclic potentiodynamic polarization resistance measurement. A potentiostaircase polarization method was used to eliminate hysteresis. A graphic averaging technique was developed to determine the polarization resistance of a system where the corrosion potential Ecorr and the corrosion rate were changing rapidly.

Author Information

Hirozawa, ST
BASF Wyandotte Corporation, Wyandotte, MI
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: G01
Pages: 108–121
DOI: 10.1520/STP33773S
ISBN-EB: 978-0-8031-4931-1
ISBN-13: 978-0-8031-0443-3