Heterogeneous Electrode Processes and Localized Corrosion Book

Preface ix

1. Homogeneous Electrode Models and Uniform Corrosion Measurements 1

1.1 Homogeneous electrodes and traditional electrochemical methods 3

1.2 Mixed electrodes and uniform corrosion models 7

1.3 The mixed potential theory and electrochemical corrosion measurement 10

1.4 Electrochemical impedance investigation of electrode-solution interface 19

1.5 Electrochemical noise monitoring of rapid electrode processes 26

1.6 Issues and difficulties in traditional electrochemical methods 31

References 32

2. Probing Electrode Inhomogeneity, Electrochemical Heterogeneity and Localized Corrosion 37

2.1 Probing electrode inhomogeneity 39

2.2 Probing electrochemical heterogeneity and localized corrosion 44

2.3 Overview of various techniques for probing localized corrosion 48

References 61

3. Visualizing Localized Corrosion Using Electrochemically Integrated Multielectrode Arrays 67

3.1 An electrochemically integrated multielectrode array: The wire beam electrode 70

3.2 Visualizing the progression of localized corrosion in an Evans water drop 76

3.3 Visualizing localized corrosion in environments with ion concentration gradients 84

3.4 Visualizing localized corrosion by the WBE in conjunction with scanning probes 91

References 99

4. Measuring Thermodynamic and Kinetic Parameters from Localized Corrosion Processes 101

4.1 Methods of probing localized corrosion thermodynamics and kinetics 103

4.2 Measuring localized corrosion using the overpotential-galvanic current method 109

4.3 Measuring localized corrosion using the galvanic current method 120

4.4 Measuring localized corrosion using the R_n-WBE method 125

References 131

5. Characterizing Inhomogeneity and Localised Corrosion on Coated Electrode Surfaces 135

5.1 Characterising inhomogeneities in organic coatings and inhibitor films 137

5.2 Characterising inhomogeneity in organic coatings using the WBE method 141

5.3 The effects of coating inhomogeneity on electrochemical measurement 145

5.4 Visualisng underfilm corrosion and the effects of cathodic protection 148

5.5 Studying corrosion protection by coatings and cathodic protection 155

References 157

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

6.1 Basic issues in localized corrosion and inhibitor test design 162

6.2 Fundamental considerations in selecting corrosion measurement techniques 165

6.3 Designing corrosion tests in highly-resistive and inhomogeneous media 168

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

6.5 Case study: Designing experiments for localized corrosion inhibitor discovery 186

References 190

7. Sensing Localized Electrodeposition and Electrodissolution195

7.1 Experimental methods for sensing localized electrodeposition and 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 organic coatings 211
References 216

8. Versatile Heterogeneous Electrode Processes 219

8.1 Scanning and modeling various heterogeneous electrode processes 222

8.2 Electrochemical noise generation from electrochemical heterogeneity 225

8.3 Harvesting electrical power from electrochemical using the WBE 231

8.4 Further research issues on electrochemical heterogeneity 237

References 238

Index 243