Cathodic Protection – Industrial Solutions for Protecting Against Corrosion

<p>Acknowledgements xv</p>
<p>Preface xvii</p>
<p>1 Corrosion of Materials 1</p>
<p>1.1 Deterioration or Corrosion of Ceramic Materials 2</p>
<p>1.2 Degradation or Deterioration of Polymers 3</p>
<p>1.3 Corrosion or Deterioration of Metals 3</p>
<p>2 Factors Influencing Corrosion 19</p>
<p>2.1 Nature of the Metal 19</p>
<p>2.2 Nature of the Corroding Environment 22</p>
<p>3 Corrosion Mechanisms 25</p>
<p>3.1 Direct Chemical Attack or Chemical or Dry Corrosion 25</p>
<p>3.2 Electrochemical or Aqueous or Wet Corrosion 29</p>
<p>3.3 Differences between Chemical and Electrochemical Corrosion 32</p>
<p>4 Corrosion Types 35</p>
<p>4.1 Uniform Corrosion 35</p>
<p>4.2 Non–Uniform Corrosion 46</p>
<p>5 Thermodynamics of Corrosion 75</p>
<p>5.1 Gibbs Free Energy ( G) 76</p>
<p>5.2 Passivity 78</p>
<p>5.3 Pourbaix Diagrams 80</p>
<p>5.4 Corrosion Equilibrium and Adsorptions 82</p>
<p>5.5 Concentration Corrosion Cells 85</p>
<p>5.6 Polarization 87</p>
<p>5.7 Polarization Curves 90</p>
<p>6 Corrosion Prevention and Protection 97</p>
<p>6.1 Proper Design 98</p>
<p>6.2 Choice of Material 101</p>
<p>6.2.8 Interference Effects 104</p>
<p>6.3 Protective Coatings 105</p>
<p>6.4 Changing the Environmental Factors that Accelerate Corrosion 114</p>
<p>6.5 Changing the Electrochemical Characteristic of the Metal Surface 123</p>
<p>7 Cost of Corrosion 127</p>
<p>7.1 Corrosion Preventative Measures 128</p>
<p>7.2 Lost Production Due to Plants Going out of Service or Shutdowns 128</p>
<p>7.3 Product Loss Due to Leakages 128</p>
<p>7.4 Contamination of the Product 129</p>
<p>7.5 Maintenance Costs 129</p>
<p>7.6 Overprotective Measures 129</p>
<p>8 Cathodic Protection 131</p>
<p>8.1 Sacrificial Anode Cathodic Protection Systems 132</p>
<p>8.2 Impressed Current Cathodic Protection Systems 134</p>
<p>8.3 Cathodic Protection Current Need 136</p>
<p>8.4 Effect of Coatings on Cathodic Protection 138</p>
<p>8.5 Effect of Passivation on Cathodic Protection 138</p>
<p>8.6 Automated Cathodic Protection Systems 139</p>
<p>8.7 Cathodic Protection Criteria 139</p>
<p>8.8 Reliability of Cathodic Protection Criteria 141</p>
<p>8.9 Interference Effects of Cathodic Protection Systems 142</p>
<p>8.10. Criteria for Cathodic Protection Projects 150</p>
<p>8.11. Cost of Cathodic Protection 151</p>
<p>8.12. Comparison of Cathodic Protection Systems 153</p>
<p>9 Sacrificial Anode or Galvanic Cathodic Protection Systems 157</p>
<p>9.1 Anodic Potentials and Anodic Polarization 158</p>
<p>9.2 Galvanic Cathodic Protection Current Need 159</p>
<p>9.3 Anodic Current Capacity and Anodic Current Efficiency 160</p>
<p>9.4 Service Life of an Anode 160</p>
<p>9.5 Minimum Number of Galvanic Anodes 161</p>
<p>9.6 Commonly Used Galvanic Anodes 161</p>
<p>9.7 Performance Measurements of Galvanic Anodes 169</p>
<p>9.8 Galvanic Anodic Beds 171</p>
<p>9.8.1 Anodic Bed Filling Materials 172</p>
<p>9.8.2 Anodic Bed Resistance 173</p>
<p>9.9 Sacrificial Anode Cathodic Protection Projects 175</p>
<p>9.10 Maintenance of Sacrificial Anode Cathodic Protection Systems 176</p>
<p>10 Impressed Current Cathodic Protection Systems 179</p>
<p>10.1 T/R Units 180</p>
<p>10.2 Types of Anodes 184</p>
<p>10.3 Anodic Bed Resistance 188</p>
<p>10.4 Types of Anodic Beds 190</p>
<p>10.5 Cable Cross–Sections 193</p>
<p>10.6 Impressed Current Cathodic Protection Projects 194</p>
<p>10.7 Maintenance of Impressed Current Cathodic Protection Systems 197</p>
<p>11 Corrosion and Corrosion Prevention of Concrete Structures 201</p>
<p>11.1 Concrete s Chemical Composition 202</p>
<p>11.2 Corrosion Reactions of Concrete 204</p>
<p>11.3 Factors Affecting Corrosion Rate in Reinforced Concrete Structures 205</p>
<p>11.4 Corrosion Measurements in Reinforced Concrete Structures 216</p>
<p>11.5 Corrosion Prevention of Reinforced Concrete 219</p>
<p>12 Cathodic Protection of Reinforced Concrete Steels 223</p>
<p>12.1 Current Needed for Cathodic Protection of Steel Structures 225</p>
<p>12.2 Cathodic Protection Criteria 226</p>
<p>12.3 Determination of Protection Potential 227</p>
<p>12.4 Cathodic Protection Methods for Reinforced Concrete Steels 227</p>
<p>12.5 Cathodic Protection of Pre–stressed Steel Concrete Pipes 229</p>
<p>13 Corrosion in Petroleum Industry 231</p>
<p>13.1 Hydrochloric Acid (HCl) and Chlorides 233</p>
<p>13.2 Hydrogen (H2) Gas 235</p>
<p>13.3 Hydrogen Sulfide (H2S) and Other Sulfur Compounds 236</p>
<p>13.4 Sulfuric Acid (H2SO4) 237</p>
<p>13.5 Hydrogen Fluoride (HF) 238</p>
<p>13.6 Carbon Dioxide (CO2) 238</p>
<p>13.7 Dissolved Oxygen (O2) and Water (H2O) 239</p>
<p>13.8 Organic Acids 242</p>
<p>13.9 Nitrogen (N2) Compounds and Ammonia (NH3) 242</p>
<p>13.10 Phenols 243</p>
<p>13.11 Phosphoric Acid (H3PO4) 243</p>
<p>13.12 Caustic Soda (NaOH) 244</p>
<p>13.13 Mercury (Hg) 245</p>
<p>13.14 Aluminum Chloride (AlCl3) 245</p>
<p>13.15 Sulfate Reducing Bacteria (SRB) 245</p>
<p>14 Corrosion in Pipeline Systems 247</p>
<p>14.1 Pipes Made of Iron and Its Alloys 248</p>
<p>14.2 Petroleum or Crude Oil Pipeline Systems 250</p>
<p>14.3 Water Pipeline Systems 252</p>
<p>15 Cathodic Protection of Pipeline Systems 255</p>
<p>15.1 Measurement of Terrain s Resistivity 256</p>
<p>15.2 Potential Measurements 257</p>
<p>15.3 Determination of Coating Failures Based on Potential Measurements 259</p>
<p>15.4 Measuring Potential along the Pipeline 260</p>
<p>15.5 Maintenance of Pipeline Cathodic Protection Systems 261</p>
<p>15.6 Measurement Stations 262</p>
<p>15.7 Static Electricity and Its Prevention 265</p>
<p>15.8 Cathodic Protection of Airport Fuel Distribution Lines 266</p>
<p>15.9 Cathodic Protection of Water Pipelines 267</p>
<p>16 Corrosion and Cathodic Protection of Crude Oil or Petroleum Storage Tanks 269</p>
<p>16.1 Cathodic Protection of Inner Surfaces of Crude Oil Storage Tanks 270</p>
<p>17 Corrosion and Cathodic Protection of Metallic Structures in Seawater 279</p>
<p>17.1 Factors Affecting Corrosion Rate of Metallic Structures in Seawater 280</p>
<p>17.2 Cathodic Protection of Metallic Structures in the Sea 284</p>
<p>17.3 Cathodic Protection of Ships 285</p>
<p>17.4 Cathodic Protection of Pier Poles with Galvanic Anodes 292</p>
<p>18 Cathodic Protection of the Potable Water Tanks 295</p>
<p>19 Corrosion and Corrosion Prevention in Boilers 297</p>
<p>19.1 Corrosion in Boilers 298</p>
<p>19.2 Corrosion Prevention in Boilers 301</p>
<p>20 Corrosion and Corrosion Prevention in Geothermal Systems 305</p>
<p>20.1 Corrosion in Geothermal Systems 305</p>
<p>20.2 Corrosion Prevention in Geothermal Systems 306</p>
<p>References 309</p>