341 صفحه
Cathodic Protection
Industrial Solutions for Protecting Against Corrosion
WILEY
2013
سرفصل مطالب:
1 Corrosion of Materials 1
1.1 Deterioration or Corrosion of Ceramic Materials 2
1.2 Degradation or Deterioration of Polymers 3
1.3 Corrosion or Deterioration of Metals 3
1.3.1 Iron, Steel and Stainless Steels 4
1.3.2 Aluminum and Its Alloys 9
1.3.3 Magnesium and Its Alloys 12
1.3.4 Copper and Its Alloys 13
1.3.5 Nickel and Its Alloys 14
1.3.6 Titanium and Its Alloys 14
1.3.7 Lead and Its Alloys 14
1.3.8 Corrosion of Composite Alloys
(Tin Can Example) 15
2 Factors Influencing Corrosion 19
2.1 Nature of the Metal 19
2.1.1 Position in Galvanic Series 19
2.1.2 Relative Areas of the Anode and Cathode 20
2.1.3 Purity of Metal 20
2.1.4 Physical State of the Metal 20
2.1.5 Passivity or Passivation 20
2.1.6 Nature of the Corrosion Product 21
2.1.7 Nature of the Oxide Film 21
2.2 Nature of the Corroding Environment 22
2.2.1 Effect of Temperature 22
2.2.2 Dissolved Oxygen Concentration and
Formation of Oxygen Concentration Cells 22
2.2.3 Nature of the Electrolyte 22
2.2.4 Presence of Corrosive Ions 23
2.2.5 Flow Rate 23
2.2.6 Humidity 23
2.2.7 Effect of pH 23
2.2.8 Presence of Impurities in the Atmosphere 24
Corrosion Mechanisms 25
3.1 Direct Chemical Attack or Chemical or
Dry Corrosion 25
3.1.1 Oxidation Corrosion 26
3.1.2 Corrosion by Other Gases 28
3.1.3 Liquid Metal Corrosion 29
3.2 Electrochemical or Aqueous or Wet Corrosion 29
3.3 Differences between Chemical and
Electrochemical Corrosion 32
Corrosion Types 35
4.1 Uniform Corrosion 35
4.1.1 Atmospheric Corrosion 37
4.1.2 Corrosion in Water 39
4.1.3 Underground or Soil Corrosion 42
4.1.4 High Temperature Corrosion 45
4.2 Non-Uniform Corrosion 46
4.2.1 Galvanic Corrosion 47
4.2.2 Crevice Corrosion 49
4.2.3 Pitting Corrosion 50
4.2.4 Selective Leaching or Selective Corrosion 52
4.2.5 Filiform Corrosion 53
4.2.6 Erosion Corrosion 54
4.2.7 Cavitation Corrosion 56
4.2.8 Abrasion Corrosion 56
4.2.9 Stress Corrosion 57
4.2.10 Intergranular Corrosion 61
4.2.11 Caustic Embrittlement 63
4.2.12 Hydrogen Embrittlement 64
4.2.13 Corrosion Fatigue 67
4.2.14 Fretting Corrosion 70
4.2.15 Stray-current and Interference Corrosion 70
4.2.16 Waterline Corrosion 71
4.2.17 Microbial or Biocorrosion 71
Thermodynamics of Corrosion
Gibbs Free Energy (AG)
Passivity
Pourbaix Diagrams
Immunity Region
Corrosion Regions
Passivity Region
Corrosion Equilibrium and Adsorptions
Concentration Corrosion Cells
Polarization
Activation Polarization
Concentration Polarization
Ohmic Polarization
Polarization Curves
Corrosion Prevention and Protection
Proper Design
Choice of Material
Purity of the Chemicals in the
Environment
Electrolyte Concentrations
Nature of the Electrolyte
Effect of Corrosion Products
Temperature Variations
Presence of Oxygen
Oxygen Concentration Cells
Interference Effects
Protective Coatings
6.3.1 Protective Oxide Films and Passivation
6.3.2 Coatings with Metals, Alloys or
Materials that are Conductors 107
6.3.3 Coating with Inorganic Materials that
are Insulators 111
6.3.4 Coating with Organic Materials that
are Insulators 112
6.4 Changing the Environmental Factors that
Accelerate Corrosion 114
6.4.1 Reducing the Corrosivity of the Solution 115
6.4.2 Inhibitors 117
6.4.3 Eliminating Galvanic Action 122
6.5 Changing the Electrochemical Characteristic of the
Metal Surface 123
6.5.1 Cathodic Protection 123
6.5.2 Anodic Protection 123
Cost of Corrosion 127
7.1 Corrosion Preventative Measures 128
7.2 Lost Production Due to Plants Going out of
Service or Shutdowns 128
7.3 Product Loss Due to Leakages 128
7.4 Contamination of the Product 129
7.5 Maintenance Costs 129
7.6 Overprotective Measures 129
Cathodic Protection 131
8.1 Sacrificial Anode Cathodic Protection Systems 132
8.2 Impressed Current Cathodic Protection Systems 134
8.3 Cathodic Protection Current Need 136
8.4 Effect of Coatings on Cathodic Protection 138
8.5 Effect of Passivation on Cathodic Protection 138
8.6 Automated Cathodic Protection Systems 139
8.7 Cathodic Protection Criteria 139
8.7.1 -850 mV Criterion 139
8.7.2 300 mV Potential Shift Criterion 140
8.7.3 100 mV Polarization Shift Criterion 140
8.7.4 Tafel Region Starting Point 141
8.8 Reliability of Cathodic Protection Criteria 141
8.9 Interference Effects of Cathodic
Protection Systems 142
8.9.1 Anodic Interference 142
8.9.2 Cathodic Interference 144
8.9.3 Specific Interference Cases 146
8.10. Criteria for Cathodic Protection Projects 150
8.11. Cost of Cathodic Protection 151
8.12. Comparison of Cathodic Protection Systems 153
9 Sacrificial Anode or Galvanic Cathodic
Protection Systems 157
9.1 Anodic Potentials and Anodic Polarization 158
9.2 Galvanic Cathodic Protection Current Need 159
9.3 Anodic Current Capacity and Anodic
Current Efficiency 160
9.4 Service Life of an Anode 160
9.5 Minimum Number of Galvanic Anodes 161
9.6 Commonly Used Galvanic Anodes 161
9.6.1 Magnesium Anodes 164
9.6.2 Zinc Anodes 165
9.6.3 Aluminum Anodes 167
9.7 Performance Measurements of Galvanic Anodes 169
9.7.1 Chemical Composition 169
9.7.2 Mechanical Strength 169
9.7.3 Electrical Resistivity 169
9.7.4 Electrochemical Experiments 170
9.8 Galvanic Anodic Beds 171
9.8.1 Anodic Bed Filling Materials 172
9.8.2 Anodic Bed Resistance 173
9.9 Sacrificial Anode Cathodic Protection Projects 175
9.10 Maintenance of Sacrificial Anode Cathodic
Protection Systems 176
9.10.1 Low Pipeline/Terrain Potential 177
9.10.2 Decreases in Anodic Current Production 178
10 Impressed Current Cathodic Protection Systems 179
10.1 T/R Units 180
10.1.1 Efficiency of T/R Units 181
10.1.2 T/R Units with Constant Potentials 182
10.1.3 Installation of T/R Units 182
10.1.4 Technical Properties of T/R Units 183
10.2 Types of Anodes 184
10.2.1 Graphite Anodes 185
10.2.2 Iron-Silicon Anodes 185
10.2.3 Silver-Lead Anodes 186
10.2.4 Titanium Anodes Coated with
Platinum 187
10.2.5 Titanium Anodes Coated with
Metal Oxides 187
10.3 Anodic Bed Resistance 188
10.4 Types of Anodic Beds 190
10.5 Cable Cross-Sections 193
10.6 Impressed Current Cathodic Protection Projects 194
10.7 Maintenance of Impressed Current Cathodic
Protection Systems 197
10.7.1 Periodical Measurements and Controls
of the Entire System 197
10.7.2 Periodical Measurements and Controls
of the T/R Unit 198
10.7.3 Commonly Encountered Problems 199
11 Corrosion and Corrosion Prevention of
Concrete Structures 201
11.1 Concrete's Chemical Composition 202
11.2 Corrosion Reactions of Concrete 204
11.3 Factors Affecting Corrosion Rate in Reinforced
Concrete Structures 205
11.3.1 Effect of Concrete Composition 205
11.3.2 Effect of Oxygen 206
11.3.3 Effect of Humidity 206
11.3.4 Effect of Temperature 208
11.3.5 Effect of pH 209
11.3.6 Effect of Chlorides 211
11.3.7 Effect of Magnesium Ions 215
11.4 Corrosion Measurements in Reinforced
Concrete Structures 216
11.4.1 Observational Methods 216
11.4.2 Weight Loss Measurements 216
11.4.3 Potential Diagrams 217
11.4.4 Polarization Curves 218
11.5 Corrosion Prevention of Reinforced Concrete 219
11.5.1 Via Coatings 220
11.5.2 Via Inhibitors 221
11.5.3 Via Cathodic Protection 221
12 Cathodic Protection of Reinforced Concrete Steels 223
12.1 Current Needed for Cathodic Protection of
Steel Structures 225
12.2 Cathodic Protection Criteria 226
12.2.1 -770 mV Potential Criterion 226
12.2.2 300 mV Potential Shift 226
12.2.3 100 mV Polarization Shift 226
12.3 Determination of Protection Potential 227
12.4 Cathodic Protection Methods for Reinforced
Concrete Steels 227
12.4.1 Via Iron-Silicon Anodes 227
12.4.2 Via Conductive Polymeric Cage Anodes 228
12.4.3 Via Titanium Sieve Anodes Coated
with Oxides 228
12.4.4 Via Conducting Paints 228
12.5 Cathodic Protection of Pre-stressed Steel
Concrete Pipes 229
13 Corrosion in Petroleum Industry 231
13.1 Hydrochloric Acid (HC1) and Chlorides 233
13.2 Hydrogen (H2) Gas 235
13.3 Hydrogen Sulfide (H2S) and Other
Sulfur Compounds 236
13.4 Sulfuric Acid (H2S04) 237
13.5 Hydrogen Fluoride (HF) 238
13.6 Carbon Dioxide (C02) 238
13.7 Dissolved Oxygen (02) and Water (H20) 239
13.8 Organic Acids 242
13.9 Nitrogen (N2) Compounds and
Ammonia (NH3) 242
13.10 Phenols 243
13.11 Phosphoric Acid (H3P04) 243
13.12 Caustic Soda (NaOH) 244
13.13 Mercury (Hg) 245
13.14 Aluminum Chloride (A1C13) 245
13.15 Sulfate Reducing Bacteria (SRB) 245
14 Corrosion in Pipeline Systems 247
14.1 Pipes Made of Iron and Its Alloys 248
14.1.1 Cast Iron Pipes 249
14.1.2 Ductile Cast Iron Pipes 250
14.1.3 Steel Pipes 250
14.2 Petroleum or Crude Oil Pipeline Systems 250
14.3 Water Pipeline Systems 252
14.3.1 Water Pipelines Made of Iron and Steel 252
14.3.2 Galvanized Water Pipelines 252
14.3.3 Water Pipelines Made of Copper 253
14.3.4 Water Pipelines Made of Brass 254
15 Cathodic Protection of Pipeline Systems 255
15.1 Measurement of Terrain's Resistivity 256
15.2 Potential Measurements 257
15.2.1 Redox Potential of the Terrain 257
15.2.2 Static Potential & On-Off Potentials 258
15.2.3 Measurement of Pipeline/Terrain
Potential 259
15.3 Determination of Coating Failures Based on
Potential Measurements 259
15.3.1 Determination of Coating Failures Based
on the Measured Pipeline /Terrain
Potentials 259
15.3.2 Determination of Coating Failures Based
on the Pearson Method 260
15.4 Measuring Potential along the Pipeline 260
15.4.1 Long Cable Method 260
15.4.2 Double Electrode Method 261
15.5 Maintenance of Pipeline Cathodic
Protection Systems 261
15.6 Measurement Stations 262
15.6.1 STP Regular Measurement Units 263
15.6.2 ATP Current Measurement Units 263
15.6.3 SATP Galvanic Anode
Measurement Units 264
15.6.4 SIF Insulated Flange Measurement Units 264
15.6.5 EPC Equivalent Potential
Measurement Units 264
15.6.6 CTP Measurement Units 264
15.7 Static Electricity and Its Prevention 265
15.8 Cathodic Protection of Airport Fuel
Distribution Lines 266
15.9 Cathodic Protection of Water Pipelines 267
16 Corrosion and Cathodic Protection of Crude Oil or
Petroleum Storage Tanks 269
16.1 Cathodic Protection of Inner Surfaces of
Crude Oil Storage Tanks 270
16.1.1 Corrosion Prevention 271
16.1.2 Sacrificial Anode Cathodic Protection 272
16.1.3 Sacrificial Anode Cathodic Protection
Current Need 273
16.1.4 Problems with Cathodic Protection of
Storage Tanks 275
17 Corrosion and Cathodic Protection of Metallic
Structures in Seawater 279
17.1 Factors Affecting Corrosion Rate of Metallic
Structures in Seawater 280
17.1.1 Effect of Resistivity on Corrosion in
Seawater 280
17.1.2 Effect of pH on Corrosion in Seawater 280
17.1.3 Effect of Temperature on Corrosion in
Seawater 281
17.1.4 Effect of Dissolved Oxygen
Concentration 282
17.1.5 Effect of Fluid Rate 284
17.2 Cathodic Protection of Metallic Structures
in the Sea 284
17.2.1 Cathodic Protection Current Need 284
17.2.2 Cathodic Protection Criteria 285
17.3 Cathodic Protection of Ships 285
17.3.1 Painting the Ships 286
17.3.2 Sacrificial Anode Cathodic Protection
of Ships 287
17.3.3 Impressed Current Cathodic Protection
of Ships 289
17.3.4 General Guidelines about Cathodic
Protection of the Ships 291
17.4 Cathodic Protection of Pier Poles with
Galvanic Anodes 292
18 Cathodic Protection of the Potable Water Tanks 295
19 Corrosion and Corrosion Prevention in Boilers 297
19.1 Corrosion in Boilers 298
19.2 Corrosion Prevention in Boilers 301
19.2.1 Degassing 301
19.2.2 Chemical Conditioning 302
20 Corrosion and Corrosion Prevention in
Geothermal Systems 305
20.1 Corrosion in Geothermal Systems 305
20.2 Corrosion Prevention in Geothermal Systems 306
References 309
Cathodic Protection, WILEY, 2013 کتاب
