Corrosion Chemistry (eBook)

Volkan Cicek, Ph.D., is a chemist and corrosion scientist and received his B. Sc. in Bogazici University, Istanbul, Turkey and his Ph.D. from Oklahoma State University, Stillwater, OK, US. After working as a dean of academics and vice principal in US public schools for several years, Dr. Cicek currently works as the vice president for scientific affairs at Ishik University, Erbil, Iraq. Bayan Al-Numan, Ph.D., is a civil and a structural engineer who received his B. Sc. and MS from Baghdad University, and his Ph.D. from University of Mustansiriyah. Dr. Bayan Al-Numan was promoted to full professor status in Structural Engineering in Civil Engineering Department at University of Mustansiriyah and he currently is the head of civil engineering department at Ishik University, Erbil, Iraq.

List of tables ix

Acknowledgements xi

Preface xiii

1. Corrosion and Its Definition 01

2. The Corrosion Process and Affecting Factors 03

3. Corrosion Types Based on Mechanism 07

3.1 Uniform Corrosion 07

3.2 Pitting Corrosion 08

3.3 Crevice Corrosion 09

3.4 Galvanic Corrosion 10

3.5 Intergranular Corrosion 11

3.6 Selective Corrosion 12

3.7 Erosion or Abrasion Corrosion 12

3.8 Cavitation Corrosion 12

3.9 Fretting Corrosion 13

3.10 Stress Corrosion Cracking 13

3.11 Microbial Corrosion 13

4. Corrosion Types of Based on the Media 15

4.1 Atmospheric Corrosion 15

4.2 Corrosion in Water 18

4.3 Corrosion in Soil 20

5. Nature of Protective Metal Oxide Films 23

6. Effect of Aggressive Anions on Corrosion 27

7. Corrosion Prevention Methods 31

8. Commonly Used Alloys and their Properties 33

8.1 Aluminum 2024 Alloy 35

8.2 Aluminum 7075 Alloy 36

8.3 Aluminum 6061 Alloy 36

9. Cost of Corrosion and Use of Corrosion Inhibitors
39

10. Types of Corrosion Inhibitors 43

10.1 Anodic Inhibitors 44

10.2 Cathodic Inhibitors 44

11. Chromates: Best Corrosion Inhibitors to Date 47

11.1 Limitations on the Use of Chromates due to Toxicity 48

11.2 Corrosion Inhibition Mechanism of Chromates 53

12. Chromate Inhibitor Replacements: Current and Potential
Applications 57

12.1 Nitrites 58

12.2 Trivalent Chromium Compounds 59

12.3 Oxyanions Analogous to Chromate 59

12.4 Synergistic Use of Oxyanions Analogues of Chromate
66

13. Sol-Gels (Ormosils) as Chromate Inhibitor Replacements:
Properties and Uses 69

13.1 Types of Sol-Gel s 69

13.1 Types of Sol-Gels 70

13.2 Corrosion Inhibition Mechanism of Sol-Gel Coatings 72

13.3 Synthesis of Sol-Gels 75

13.4 Incorporation of Corrosion Inhibitive Pigments to Sol-Gel
Coatings 77

14. Corrosion in Engineering Materials 81

14.1 Introduction 81

14.2 Steel Structures 82

14.3 Concrete Structures 85

14.4 Protection against Corrosion in Construction 95

14.5 Corrosion of Unbonded Prestressing Tendons 116

14.6 Cathodic Protection 120

14.7 Corrosion in Industry Projects 135

References 145

Index 173