Welding Inspection Handbook

Welding Inspection Handbook

Fourth Edition 2015

Prepared by the

AWS B1C Standing Task Group on Welding Inspection Handbook

Under the Direction of the AWS Technical Activities Committee

Approved by the AWS Board of Directors

ISBN: 978-0-87171-855-6

© 2015 by American Welding Society

All rights reserved Printed in the United States of America

THE WELDING INSPECTION HANDBOOK is a collective effort of many volunteer technical special- ists to provide information to assist welding inspectors and supervisors in the technology and application of visual and nondestructive examination.

Reasonable care is taken in the compilation and publication of the Welding Inspection Handbook to ensure authenticity of the contents. However, no representation is made as to the accuracy or reliability of this information, and an independent substantiating investigation should be undertaken by any user.

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The information contained in the Welding Inspection Handbook shall not be construed as a grant of any right of manufacture, sale, use, or reproduction in connection with any method, process, apparatus, product, composition, or system, which is covered by patent, copyright, or trademark. Also, it shall not be construed as a defense against any liability for such infringe- ment. Whether or not use of any information in the Handbook would result in an infringement of any patent, copyright, or trademark is a determination to be made by the user.

Personnel

AWS B1C Standing Task Group on Welding Inspection Handbook

U. Aschemeier, Chair Subsea Global Solutions LLC

E. Abrams, Secretary American Welding Society

B. Baker Bechtel National, Incorporated

R. Campbell Banker Steel Company

R. Clarke TEAM Industrial Services

R. Cook SME Steel Contractors

G. Gratti Arcos Industries LLC

E. Lichtfusz Roush Industries

C. Mankenberg Shell International Exploration & Production

J. Mehta Alta Vista Solutions

A. Moore Marion Testing & Inspection

H. Thompson UL LLC

Special Contributor

W. Komlos Arc Tech LLC

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Foreword

The inspection of welds and welded assemblies requires knowledge of many factors of welding quality control. This includes dimensional inspection, nondestructive examination methods, welding processes, welding metallurgy, destructive testing, and the qualification of welding procedures and personnel. It also includes the examination and test requirements of codes, cri- teria, and specifications; the acceptance standards to be employed; and an understanding of drawings, and welding and nondestructive examination symbols. Knowledge about discontinu- ities that may be associated with different welding processes, and the ability to evaluate the dif- ference between discontinuities and rejectable defects, is also an important element of welding inspection.

This fourth edition of the Welding Inspection Handbook has been prepared by the AWS B1C Welding Inspection Handbook Task Group. The objective is to provide a reliable source of use- ful reference information. This is particularly relevant for the technically trained individual who may not be directly involved with inspection but whose position requires knowledge about welding inspection. This book also is intended for the inspector who needs a general refresher in the basic requirements of weld inspection. This fourth edition supersedes the AWS Welding Inspection Handbook bearing the same title, and includes changes to numerous clauses to provide clarification, correct inconsistencies, and updates representative of current industry practices.

Underlined text in the clauses and subclauses indicates a change from the 2000 edition. A vertical line in the margin indicates a revision from the 2000 edition.

Additional books on the subjects covered in each chapter may be found in good technical libraries. The many specifications and codes that have been used as examples may also be con- sulted for more detailed information.

This book is an instructive reference. Codes or specifications applicable to any particular weld- ment always take precedence over the generalized material contained herein. The text of this book has, of necessity, been written in general terms and cannot include all the conditions applicable to a specific instance. Thus, examples given are general and are used only for the purpose of illustration.

Every effort has been made to present this material in convenient form so that the book can be used as a training text for inspectors, engineers, and welders. Although the information gener- ally relates to the arc welding processes, most of it applies to any weldment—fabricated by any joining process—for which the inspection methods described herein may be required.

For the inspection of brazed assemblies, refer to The Brazing Handbook published by the American Welding Society. For the inspection of resistance welded assemblies, refer to AWS/ SAE D8.7, Recommended Practices for Automotive Weld Quality—Resistance Spot Welding, also published by the American Welding Society.

Information on nondestructive examination methods is available in AWS B1.10M/B1.10, Guide for Nondestructive Examination of Welds, and in AWS B1.11M/B1.11, Guide for the Visual Examination of Welds.

Comments and inquiries concerning this publication are welcome. They should be sent to the Managing Director, Technical Services Division, American Welding Society, 8669 NW 36 St,

# 130, Miami, FL 33166.

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Contents

Chapter Page

Personnel iii

Foreword v

List of Tables viii

List of Figures ix

1. Scope and Application 1

2. Symbols 3

3. Requirements for the Welding Inspector. 13

4. Welding Inspection Operations 21

5. Inspection Safety Considerations 27

6. Quality Assurance 33

7. Ferrous Welding Metallurgy 37

8. Preheating and Postweld Heat Treating 53

9. Weld and Weld Related Discontinuities 57

10. Qualification of Welding Procedure Specifications 75

11. Qualification of Welders and Welding Operators 91

12. Computerization of Welding Inspection and Quality. 103

13. Destructive Testing of Welds 111

14. Proof Tests 137

15. Nondestructive Examination Methods 141

16. Qualification of Nondestructive Examination Personnel 239

17. Codes and Other Standards 241

18. Metric Practice 255

Index 267

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List of Tables

Table Page

4.1 Sequence of Welding and Inspection Operations 24

10.1 Welding Procedure Specification and Welder Qualification Factors

Which May Require Requalification 81

13.1 Typical Hardness Conversion Table (Approximate) (for Carbon and

Low-Alloy Steels in Accordance with ASTM E140 and ASTM A370) 120

1. Considerations when Selecting an NDE Method 143

2. Radiographic Isotopes Used in Industrial Radiography 155

3. Approximate Radiographic Equivalence Factors of Several Metals 157

4. Resistivity and Conductivity of Some Metals and Alloys 218

1. SI Base and Supplementary Units and Symbols 255

2. SI Derived Units and Symbols 256

3. SI Factors, Prefixes, and Symbols 256

4. Units Not Part of the SI System 257

5. SI Unit Conversion Factors 258

6. General Conversion Factors 258

7. Commonly Used Metric Conversions (Inch–Millimeter Conversion) 262

8. Pressure and Stress Equivalents—psi and ksi to kPa and MPa 263

9. Conversions for Fahrenheit–Celsius Temperature Scales 264

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List of Figures

Figure Page

1. AWS Standard Welding Symbols 4

2. Comparison of Welding Symbol and Written Explanation. 6

3. Examples of Typical Fillet Welds Showing the Corresponding Symbols

   and Dimensions 7

4. Examples of Typical Groove Welds Showing the Corresponding

   Symbols and Dimensions 8

5. Standard Location of Elements for NDE Symbols 9

6. Examples of Typical Nondestructive Examination Symbols 9

7. Master Chart of Welding, Allied Processes, and Thermal Cutting 10

5.1 SDS Sheet 28

1. Iron-Carbon Phase Diagram 38

2. Crystal Structure of Cold Rolled Steel in Weld Area 39

3. Martensite Showing Needle-Like or Acicular Structure

   (500X Before Reduction) 40

4. Example of Delayed Cracking in HAZ 42

5. Corrosion Attack of Sensitized Stainless Steel in Acid Environment 46

6. Microfissure in Austenitic Stainless Steel (100X) 47

7. Closeup of Lamellar Tear Under a Fillet Weld Showing Typical Stepped

Appearance (Magnification 8X) 48

1. Typical Distortion of Welded Joints 59

2. Overlap 61

3. Weld Sizes 61

4. Incomplete Joint Penetration and Incomplete Fusion 63

5. Underfill 65

6. Various Types of Cracks. 66

7. Porosity 70

1. AWS Structural Welding Code, Welding Procedure Example Form 79

2. Example of a Suggested Procedure Qualification Record (PQR) 86

3. ASME Welding Procedure Qualification Record Example Form 88

11.1A Test Plate for Unlimited Thickness—Welder Qualification 93

1. B Optional Test Plate for Unlimited Thickness—Horizontal Position—

   Welder Qualification 93

2. A Tubular Butt Joint—Welder Qualification—Without Backing 94

1. B Tubular Butt Joint—Welder Qualification—With Backing 94

2. A Positions of Groove Welds 95

1. B Positions of Fillet Welds 96

2. Positions of Test Plates for Groove Welds 97

3. Positions of Test Pipe or Tubing for Groove Welds 98

4. Positions of Test Plate for Fillet Welds 99

5. Positions of Test Pipes for Fillet Welds 100

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   Figure Page

6. Suggested Form for Welding Performance Qualification 101

12.1 A Welding Inspection Database 105

1. Typical Photomacrographs 114

2. Photomicrograph Illustrating the Appearance of a Crack in the

   Heat-Affected Zone (Approximately 100X) 114

3. Photomicrographs 115

4. Typical Stress-Strain Diagram Used in the Offset Method 121

5. Standard Tension Specimens. 123

6. A Transverse Face- and Root-Bend Specimens 126

1. B Transverse Side-Bend Specimens 127

2. Fixture for Guided Bend Test 128

3. A Transverse Rectangular Tension Test Specimen (Plate) 130

1. B Longitudinal Rectangular Tension Test Specimen (Plate) 131

2. Typical Fillet Weld Break and Macroetch Test for Fillet Welder or

   Welding Operator Qualification 132

3. Charpy (Simple-Beam) Impact Test Specimens 134

4. Charpy (Simple-Beam) Impact Test 135

1. Welding Engineer Data Sheet 146

2. Rulers, Measuring Tapes, and Gauges for Checking Fitup and Weld Dimensions . 147 15.3 Weld Bead Contours 148

1. Workmanship Standard 149

2. Sketches of Weld Undercut and Overlap 150

3. Photographs of Weld Undercut and Overlap. 151

4. Weld Inspection Gauges 152

5. Typical “Shadow Graph” 154

6. The Penumbral Shadow 158

7. Geometric Principles of Shadow Formation 159

8. Factors Affecting Quality of Radiographic Image 162

9. Sources of Scattered Radiation 164

10. Characteristic Curve For a Typical Industrial X-Ray Film 166

11. The “Tools of The Trade” for the Radiographer 169

12. Typical Penetrameter Design 170

13. Typical Radiographic Exposure Arrangements 172

14. Typical Radiographs of Weld Discontinuities 177

15. Block Diagram, Pulse-Echo Flaw Detector 179

16. Decibel-To-Screen Height or Voltage Nomograph 181

17. Snell’s Law of Reflection and Refraction 183

18. Amplitude Calibration Using Flat Bottom Holes 185

19. Shear Wave Ultrasonic Beam 185

20. Amplitude Calibration 186

21. Ultrasonic Ruler Application 190

22. Flaw Orientation. 191

23. Sound Beam Propagation Showing Sound Path Distance 191

24. Magnetic Field in a Bar Magnet 194

25. Magnetic Field in a Bar Magnet That Has Been Cut in Half 195

26. Magnetism Around a Notch Cut in a Bar Magnet 196

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    Figure Page

27. Magnetic Field Around a Conductor Carrying Current 197

28. Field of Ferromagnetic Conductor is Confined Almost Entirely to the

    Conductor Itself. 197

29. Magnetic Particles Near a Defect are Attracted to the Local Poles 197

30. In Large Parts, Local Areas Can Be Magnetized; Arrows Indicate Field 198

31. Part to be Inspected Can Be Magnetized by Making it the Core of a Solenoid 199

32. Crack in Large Plate is Indicated by Alignment of Particles Between Prods 200

33. Dry Powder Magnetic-Particle Inspection of Welds with Portable

    Equipment 202

34. Wet Fluorescent Magnetic-Particle Inspection to Show Fine Surface Defects 203

35. Typical Indication of Surface Crack in a Weld 207

36. Indication of a Subsurface Crack in a Weld (The Dry Magnetic

    Particles Assume a Less Defined Pattern). 208

37. Liquid Penetrant Comparator 213

38. Frequencies Used for Various Test Problems 215

39. Cross-Sectional View of a Bar with a Small Crack, Surrounded by an

    Exciting Coil and a Pickup Coil, Showing Eddy Current Distribution 216

40. Relative Conductivity of Metals and Alloys Related to Eddy Current

    Meter Readings 217

41. Influence of Impurities on the Conductivity of Pure Copper 219

42. Typical B/H (Hysteresis) Curve 220

43. Lines of Magnetic Flux Surrounding a Solenoid 220

44. A Instrumentation Readout for Electromagnetic Testing 221

1. B Typical Eddy Current Readout from Strip Chart Illustrating Good and Bad

   Weld Areas 221

2. Production of Eddy Currents by an Alternating Field 222

3. Testing Coils Carrying Alternating Current 223

4. Examples of Electromagnetic Probe Coils 224

5. Eddy Current Strength Drops Off With Distance From Surface 224

6. Eddy Current Flaw Detection Equipment 225

7. Microstructure of Austenitic Weld Specimen 232

8. Schaeffler Diagram for Stainless Steel Weld Metal 233

9. DeLong Diagram for Stainless Steel Weld Metal 234

10. Typical Flow Diagram from Contract to Approved Operations Procedures 235

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Chapter 1 Scope and Application

1. Scope

   The scope of this handbook includes testing and examination methods that apply to a majority of metallic and nonmetallic weldments used in construction. The extent of inspections should be clearly defined in contract documents or on drawings that refer to a particular weldment (unless otherwise defined in applicable codes or specifications). Furthermore, acceptance crite- ria should be clearly understood and agreed upon by both the supplier and the purchaser before any production welding begins. Acceptance criteria for weld discontinuities are specifically excluded from this handbook.

   It is the responsibility of those charged with the administration and supervision of inspection to make certain that the principles and methods to be used are properly understood and applied uniformly. This responsibility may include the qualification and certification of inspectors where such certification is required by codes, specifications, job contracts, civil law, or com- pany policies.

   The following documents address the qualification of welding inspection and nondestructive examination personnel:1

   1. AWS QC1, Standard for AWS Certification of Welding Inspectors

   2. AWS B5.1, Specification for the Qualification of Welding Inspectors

   3. ANSI/ASNT CP-189, ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel

   4. ASNT Recommended Practice SNT-TC-1A, Personnel Qualification and Certification in Nondestructive Testing

   5. ASTM 1316, Standard Terminology for Nondestructive Testing

   6. ISO 9712, Nondestructive Testing—Qualification and Certification of NDT personnel

      Even when a particular qualification for certification program is not mandatory, every welding inspector should be aware of the ethical criteria for welding inspectors contained in documents such as AWS QC1.

      
      

2. Application

The information in this handbook pertains to the general duties and responsibilities of welding inspectors and is intended as a reference to help their performance. This book provides specific information about methods of weldment inspection; however, much of the information will also generally apply to the examination of nonwelded components, such as base metal inspection prior

1. See Chapter 17 for addresses of standards writing organizations.

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