Application of electrochemical impedance spectroscopy (EIS) for monitoring of SCC-cracks

Conference · Mon Nov 01 04:00:00 EST 1999

OSTI ID:697095

Bosch, R W; Moons, F ^[1]; Zheng, J H; Bogaerts, W F ^[2]

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1. Nuclear Research Centre Belgium, Mol (Belgium)
2. KU Leuven, Heverlee (Belgium). Dept. of Metallurgy and Materials Engineering

It was investigated if Electrochemical Impedance Spectroscopy (EIS) could be used for the monitoring of Stress Corrosion Cracking (SCC). First a model was developed that described the impedance response of a cracked surface, i.e. the model could distinguish between a flat electrode surface and a surface with cracks. Experiments with stainless steel electrodes with artificial cracks (electrically drilled small holes) in 0.1 M Na{sub 2}SO{sub 4} showed that the influence of the artificial cracks on the impedance response was mainly reflected in the phase shift at frequencies between 100 and 1 Hz. To generate real stress corrosion cracks, Slow Strain Rate Tests (SSRT) were performed with sensitized SS 304 specimen in a 5 N H{sub 2}SO{sub 4} + 0.1 M NaCl solution at room temperature. Analysis of the fracture surface clearly shows intergranular attack, suggesting that stress corrosion cracks were formed. Impedance measurements were performed twice an hour during experiments with stress (SSRT) and without stress. Phase shifts at frequencies 100 and 10 Hz showed a clear difference between the results with stress and without stress suggesting that stress corrosion cracks were detected by the impedance measurements.

• OSTI ID: 697095
• Report Number(s): CONF-990401--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRACK PROPAGATION
ELECTROCHEMISTRY
INTERGRANULAR CORROSION
MONITORING
STAINLESS STEEL-304
STRESS CORROSION