Heterogeneous Electrode Processes and Localized Corrosion (eBook)

YONGJUN TAN is currently Associate Professor of Applied Electrochemistry and Corrosion Technology at Deakin University, Australia. Dr. Tan invented the wire beam electrode method and developed a localized corrosion probe. He has contributed to the development of the electrochemical noise analysis technique and the understanding of noise signatures. Dr. Tan has authored or coauthored more than 100 scientific and technical publications in the fields of electrochemistry and corrosion science.

Preface ix

1. Homogeneous Electrode Models and Uniform CorrosionMeasurements 1

1.1 Homogeneous electrodes and traditional electrochemicalmethods 3

1.2 Mixed electrodes and uniform corrosion models7

1.3 The mixed potential theory and electrochemicalcorrosion measurement 10

1.4 Electrochemical impedance investigation ofelectrode-solution interface 19

1.5 Electrochemical noise monitoring of rapidelectrode processes 26

1.6 Issues and difficulties in traditionalelectrochemical methods 31

References 32

2. Probing Electrode Inhomogeneity, ElectrochemicalHeterogeneity and Localized Corrosion 37

2.1 Probing electrode inhomogeneity 39

2.2 Probing electrochemical heterogeneity and localizedcorrosion 44

2.3 Overview of various techniques for probing localizedcorrosion 48

References 61

3. Visualizing Localized Corrosion Using ElectrochemicallyIntegrated Multielectrode Arrays 67

3.1 An electrochemically integrated multielectrode array: Thewire beam electrode 70

3.2 Visualizing the progression of localized corrosion in anEvans water drop 76

3.3 Visualizing localized corrosion in environments with ionconcentration gradients 84

3.4 Visualizing localized corrosion by the WBE in conjunctionwith scanning probes 91

References 99

4. Measuring Thermodynamic and Kinetic Parameters fromLocalized Corrosion Processes 101

4.1 Methods of probing localized corrosion thermodynamics andkinetics 103

4.2 Measuring localized corrosion using theoverpotential-galvanic current method 109

4.3 Measuring localized corrosion using the galvanic currentmethod 120

4.4 Measuring localized corrosion using the Rn-WBEmethod 125

References 131

5. Characterizing Inhomogeneity and Localised Corrosion onCoated Electrode Surfaces 135

5.1 Characterising inhomogeneities in organic coatings andinhibitor films 137

5.2 Characterising inhomogeneity in organic coatings using theWBE method 141

5.3 The effects of coating inhomogeneity on electrochemicalmeasurement 145

5.4 Visualisng underfilm corrosion and the effects of cathodicprotection 148

5.5 Studying corrosion protection by coatings and cathodicprotection 155

References 157

6. Designing Experiments for Studying Localized Corrosion andIts Inhibition in Inhomogeneous Media 161

6.1 Basic issues in localized corrosion and inhibitor testdesign 162

6.2 Fundamental considerations in selecting corrosionmeasurement techniques 165

6.3 Designing corrosion tests in highly-resistive andinhomogeneous media 168

6.4 Case studies: Designing crevice corrosion tests by means ofthe WBE 181

6.5 Case study: Designing experiments for localized corrosioninhibitor discovery 186

References 190

7. Sensing Localized Electrodeposition andElectrodissolution195

7.1 Experimental methods for sensing localized electrodepositionand dissolution 197

7.2 Sensing localized electrodeposition using the WBE 200

7.3 Sensing localized electrodissolution using the WBE 204

7.4 Sensing nonuniform electrochemical deposition of organiccoatings 211
References 216

8. Versatile Heterogeneous Electrode Processes 219

8.1 Scanning and modeling various heterogeneous electrodeprocesses 222

8.2 Electrochemical noise generation from electrochemicalheterogeneity 225

8.3 Harvesting electrical power from electrochemical using theWBE 231

8.4 Further research issues on electrochemical heterogeneity237

References 238

Index 243