Methods of weld testing and analysis are used to assure the quality and correctness of the weld after it is completed. Contaminants and metallurgical flaws can be introduced into the weld via welding procedures and technologies. It is vital to ensure that a weld fulfils minimal quality criteria if it is required to endure extreme loading conditions and pressures. Destructive and non-destructive procedures can both be used to test welds. Non-destructive testing is used for the majority of production. Visual inspection, liquid penetrant, magnetic particle, eddy current, ultrasonic, acoustic emission, and radiography are the most popular non-destructive tests used to inspect welds. Non-destructive tests produce ambiguous but reliable results and, by definition, leave the test object usable for its original use.

 This book elucidates the concepts and innovative models around prospective development with respect to non-destructive testing. It provides deep insights into this field. The book is well designed based on different chapters and explains in depth about welded joints as the stress concentrator, stress model, visual methods and radiographic methods. A logical based discussion has been tried to make for better understanding of the subject matter. It also describes ultrasonic methods, magnetic methods, penetrant methods and electrical method. Such selected concepts that redefine this field have been presented in it. Different approaches, evaluations and methodologies have been included in it. This book will serve as a reference to a broad spectrum of readers.

Preface ix

1. Introduction 1

1. Introduction 1

2. Non-destructive Testing of Welds 1

3. Physical Weld Testing 5

4. Advances in Non-Destructive Inspection and Evaluation of Welds 17

5. Eddy Current Testing 24

6. Acoustic Emission Technique 26

Conclusion 29

References 30

MCQs 31

Answers 33

2. Welded Joints as the Stress Concentrator 34

1. Introduction 34

2. Welding joint 35

3. T-welded connections using finite element method 43

4. Numerical analysis on dynamic stress 54

Conclusion 57

References 57

MCQs 58

Answers 59

3. The Stress Model for the Assessment of Fatigue Life 60

1. Introduction 60

2. Fatigue of Welded Joints 61

3. Fatigue 67

4. Crack Growth Methods 73

5. A new multiaxial fatigue life prediction model considering

additional hardening effect 78

Conclusion 81

References 82

MCQs 83

Answers 84

vi

Introduction to Non Destructive Testing of Welded Joints 4. Visual Methods 85

1. Introduction 85

2. Visual Inspection 86

3. Visual Inspection of Welded Connections 87

4. Inspection and Testing of Electron Beam and Laser Welds 89

5. Weld Quality Testing 92

6. Quality inspections 100

7. Visual Weld Inspections, Before, During and After 103

Conclusion 105

References 106

MCQs 106

Answers 107

5. Radiographic Methods 108

1. Introduction 108

2. Radiographic Inspection 109

3. Differences between Radiographic and Ultrasonic Testing of

Welds 111

4. Industrial radiography 112

5. Inspection of Welding 113

Conclusions 129

References 130

MCQs 130

Answers 131

6. Ultrasonic Methods 132

1. Introduction 132

2. Process 133

3. Evaluation methods for materials for power ultrasonic applications 140

4. Measurements of Quality Factor Under High Strain 153

5. Ultrasonic Transducers for Nondestructive Testing 155

Conclusion 159

References 159

MCQs 160

Answers 161

7. Magnetic Methods 162

1. Introduction 162

2. The Unique Benefits of Magnetic Pulse Welding 163

3. Magnetic pulse welding 167

4. Plastic welding 184

Index vii

5. How does magnetism in pipes stop the welding process 195

Conclusions 197

References 198

MCQs 199

Answers 199

8. Penetrant Methods 200

1. Introduction 200

2. Penetrant and Detectability of Flaws 201

3. Basic Principles of Liquid Penetrant Inspection 201

4. Dye Penetrant Inspection 205

5. Liquid Penetrant Testing - the history and principles of the method 207

6. Basic Principles 208

7. Nondestructive Testing Methods Used for Welding 209

8. Liquid Penetrant Examination 211

9. Dye Penetration Test 215

10. Dye Penetrant Inspection Procedure 220

11. Dye Penetrant Inspection - Control of Contaminants 221

Conclusion 226

References 227

MCQs 227

Answers 228

9. Electrical Method 229

1. Introduction 229

2. Electric Arc Welding 229

3. Meaning of Electric Arc Welding 236

4. Procedure of Electric Arc Welding 237

5. Electric Resistance Welding 245

6. Arc Characteristics of MIG Welding 249

7. Gases Involved in GMA Welding 250

8. Essential Process Variables in ESW 252

Conclusion 253

References 254

MCQs 254

Answers 255

10. Other Methods of NDT 256

1. Introduction 256

2. Different Types of Non-Destructive Testing Methods 256

3. Acoustic Emission 259

viii Introduction to Non Destructive Testing of Welded Joints

4. Visual Weld Testing 266

5. Phased array ultrasonics 268

Conclusions 269

References 270

MCQs 270

Answers 271

Index 273

Tuyet Kohler obtained her Master of Science in Metallurgical Engineering from State University, Alabama. She is a Research Associate at Technical Institute, Nova Scotia. She has experience in the areas of mechanical and mechatronics engineering, with emphasis on advanced manufacturing processes including welding, automation and sensing. Kohler has spent more than 15 years in the metalwork industry and has authored numerous articles and books, which have been published worldwide. She was also awarded the “Distinguished Scholar” award for her outstanding contribution to the researcher community in the field of metal and silverworks.