AWS B1.10:1999

An American National Standard

Guide for the Nondestructive Examination

of Welds

Key Words— Guide, eddy current examination,

magnetic particle examination, nondestructive examination, penetrant examination, radiographic examination, ultrasonic examination, visual examination, leak examination,

weld discontinuities

AWS B1.10:1999

An American National Standard

Approved by American National Standards Institute

October 26, 1999

Guide for the Nondestructive Examination of Welds

Supersedes ANSI/AWS B1.10-86

Prepared by AWS Committee on Methods of Inspection

Under the Direction of AWS Technical Activities Committee

Approved by AWS Board of Directors

Abstract

550 N.W. LeJeune Road, Miami, Florida 33126

This guide acquaints the user with the nondestructive examination methods commonly used the examine weldments. The standard also addresses which method best detects various types of discontinuities The examination methods included are visual, penetrant, magnetic, radiographic, ultrasonic, electromagnetic (eddy current), and leak testing.

550 N.W. LeJeune Road, Miami, Florida 33126

Statement on Use of AWS American National Standard Standards

All standards (codes, specifications, recommended practices, methods, classifications, and guides) of the American Welding Society are voluntary consensus standards that have been developed in accordance with the rules of the Ameri- can National Standards Institute. When AWS American National Standard standards are either incorporated in, or made part of, documents that are included in federal or state laws and regulations, or the regulations of other governmental bodies, their provisions carry the full legal authority of the statute. In such cases, any changes in those AWS standards must be approved by the governmental body having statutory jurisdiction before they can become a part of those laws and regulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes the AWS standards. Where this contractual relationship exists, changes in or deviations from requirements of an AWS standard must be by agreement between the contracting parties.

International Standard Book Number: 0-87171-609-7 American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126

© 2000 by American Welding Society. All rights reserved

Printed in the United States of America

AWS standards are developed through a consensus standards development process that brings together volunteers repre- senting varied viewpoints and interests to achieve consensus. While AWS administers the process and establishes rules to promote fairness in the development of consensus, it does not independently test, evaluate, or verify the accuracy of any information or the soundness of any judgments contained in its standards.

AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whether spe- cial, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this standard. AWS also makes no guaranty or warranty as to the accuracy or completeness of any information published herein.

In issuing and making this standard available, AWS is not undertaking to render professional or other services for or on behalf of any person or entity. Nor is AWS undertaking to perform any duty owned by any person or entity to someone else. Anyone using these documents should rely on his or her own independent judgment or, as appropriate, seek the ad- vice of a competent professional in determining the exercise of reasonable care in any given circumstances.

This standard may be superseded by the issuance of new editions. Users should ensure that they have the latest edition.

Publication of this standard does not authorize infringement of any patent. AWS disclaims liability for the infringement of any patent resulting from the use or reliance on this standard.

Finally, AWS does not monitor, police, or enforce compliance with this standard, nor does it have the power to do so.

Official interpretations of any of the technical requirements of this standard may be obtained by sending a request, in writ- ing, to the Managing Director Technical Services, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 (see Annex D). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. However, such opinions represent only the personal opinions of the particular individuals giving them. These individuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpre- tations of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.

This standard is subject to revision at any time by the AWS B1 Committee. It must be reviewed every 5 years and if not re- vised, it must be either reapproved or withdrawn. Comments (recommendations, additions, or deletions) and any pertinent data that may be of use in improving this standard are requested and should be addressed to AWS Headquarters. Such comments will receive careful consideration by the AWS B1 Committee and the author of the comments will be informed of the Committee’s response to the comments. Guests are invited to attend all meetings of the AWS B1 Committee to ex- press their comments verbally. Procedures for appeal of an adverse decision concerning all such comments are provided in the Rules of Operation of the Technical Activities Committee. A copy of these Rules can be obtained from the Ameri- can Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.

Photocopy Rights

ii

Authorization to photocopy items for internal, personal, or educational classroom use only, or the internal, personal, or educational classroom use only of specific clients, is granted by the American Welding Society (AWS) provided that the appropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: 978-750-8400; online: https://www.copyright.com.

Personnel

AWS Committee on Methods of Inspection

P. A. Grimm, Chair Modern Welding Company, Incorporated

1. D. McGuire, 1st Vice Chair National Board of Boiler and Pressure Vessel Inspectors

   1. D. Levert, 2nd Vice Chair Loral Vought Systems

      1. P. Connor, Secretary American Welding Society

         *W. Borges, P.E. Consultant

         *C. R. Brashears Alyeska Pipeline Service Company

         R. Brosilow Welding Design and Fabrication

         W. A. Bruce Edison Welding Institute

         *E. L. Criscuolo Consultant

         *P. E. Deeds, Jr. Consolidated Edison Company of New York

         *C. J. Hellier Hellier Associates

         1. L. Holdren Welding Consultants, Incorporated

            *D. L. Isenhour Newport News Shipbuilding and Dry Dock Company

            *L. Laime Consultant

            *W. C. Minton Consultant

            1. W. Overy Pacific Gas and Electric Company

               *M. N. Pfeiffer Consultant

               *A. G. Portz Consultant

               *S. J. Walmsley S. J. Walmsley and Associates

            2. Zerkle Hobart Brothers Company

*Advisor

iii

Foreword

(This Foreword is not a part of AWS B1.10:1999, Guide for the Nondestructive Examination of Welds, but is included for information purposes only.)

The Guide for the Nondestructive Inspection of Welds was first prepared by the AWS Committee on Methods of Inspection in 1977. The next edition was published in 1986, the content updated to the then practices current in the industry. This Guide provides an updated source of basic information on nondestructive examination (NDE) methods, and it has been expanded to include Leak Examination. It acquaints the reader with common NDE methods available and aids in selecting the method best suited for examination of a given weld, namely: visual, penetrant, magnetic particle, radiography, ultrasonic, eddy current, and leak. Two new annexes are included in this edition. Annex C contains a typical list of industry standards, and Annex D provides guidelines for technical inquiries to AWS Committees.

The purpose of this guide is to give the reader an overview of the more common examination methods available with- out unnecessary detail and to provide an aid in deciding which method is generally best suited for the examination of a given weld.

The words examination, evaluation, inspection, and testing are considered synonymous when describing various non- destructive examination methods.

This guide has been prepared by the AWS Committee on Methods of Inspection to serve as a simple, but reliable, source of general information. It is not intended that this document provide complete and comprehensive coverage of the subject. There are many reference manuals available. For more comprehensive coverage of the activities of the welding inspector this guide should be used in conjunction with the AWS book, Welding Inspection. Welding Inspection provides a more thorough description of the duties and responsibilities of welding inspectors, the techniques and characteristics of the usual nondestructive examination methods, and the major aspects of sampling and documentation required for an ad- equate quality control system. For other references of the subject of inspection, refer also to the technical documents suggested in 1.7, Normative References, and Section 5, Supplementary Reading Material. Annex A summarizes the required equipment, applications, advantages, and limitations of each of the eight examination methods covered in the document. Annex B incorporates Part C—Nondestructive Examination Symbols of ANSI/AWS A2.4-98, Standard Symbols for Welding, Brazing, and Nondestructive Examination. Annex C provides list of typical application standards and the addresses of the standards developer. Annex D provides guidelines for making inquires to AWS Committees.

Comments and suggestions regarding this Guide are welcome. These comments should be sent to the Secretary, AWS Committee on Methods of Inspection, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.

iv

iv

Table of Contents

Page No.

Personnel iii

Foreword v

List of Tables vi

List of Figures vi

1. General 1

   1. Scope. 1

   2. Advantages and Limitations of the Inspection Method 1

   3. Acceptance Standards 1

   4. Cost 1

   5. Procedures. 2

   6. References. 2

   7. NDE Symbols 2

   8. Safety and Health 2

2. Discontinuities 2

   1. Discussion of Discontinuities 2

   2. List of Discontinuities 2

   3. Porosity 2

   4. Inclusions 5

   5. Incomplete Fusion 5

   6. Incomplete Joint Penetration 6

   7. Undercut 6

   8. Underfill 6

   9. Overlap 8

   10. Lamination 8

   11. Delamination. 8

   12. Seams or Laps 8

   13. Lamellar Tear 8

   14. Cracks 9

   15. Concavity 11

   16. Convexity 11

   17. Weld Reinforcement 11

3. Nondestructive Examination Methods 13

   3.l Visual Examination (VT) 13

   1. Penetrant Examination (PT) 14

   2. Magnetic Particle Examination (MT) 15

   3. Radiographic Examination (RT) 16

   4. Ultrasonic Examination (UT) 19

   5. Electromagnetic Examination (ET) 23

   6. Leak Examination 24

4. Interrelationships Among Welding Processes, Discontinuities, and Examination Methods 26

5. Supplementary Reading Material 26

Annex A—Examination Method Selection Guide 29

Annex B—NDE Symbols and Abbreviations 31

Annex C—Typical Industry Standards 37

Annex D—Guidelines for Preparation of Technical Inquiries for AWS Technical Committees 39

AWS Document List 41

v

v

List of Tables

Table Page No.

1. Common Types of Discontinuities 3

2. Discontinuities Commonly Encountered with Welding Processes 12

3. Common Weld Inspection Methods vs. Discontinuities 27

4. Applicable Examination Methods—Five Weld Joint Types 27

   List of Figures

   Figure Page No.

   1. Double-V-Groove Weld In Butt Joint. 4

   2. Single-Bevel-Groove and Fillet Welds in Corner Joint 5

   3. Double-Bevel-Groove Weld in T-Joint 6

   4. Double Fillet Weld in Lap Joint 7

   5. Single Pass Double Fillet Weld in T-Joint 7

   6. Single-Bevel-Groove Weld in Butt Joint 8

   7. Fillet Weld Terminology 9

   8. Fillet Weld Discontinuities 9

   9. Groove Weld Terminology 10

   10. Groove Weld Discontinuities 11

   11. Steps in Penetrant Testing 14

   12. Magnetic Field Leakage 15

   13. Direct Magnetization Using dc Prods 15

   14. Indirect Magnetization Using a Yoke 15

   15. Making a Radiograph 17

   16. Typical Radiographs of Weld Discontinuities 18

   17. Detection of Planar Discontinuities at Various Orientations by Radiography 19

   18. Block Diagram, Pulse-Echo Flaw Detector 20

   19. Similarities Between Reflections of Light and Sound at Boundaries 20

   20. Refraction 21

   21. Diffraction 21

   22. Example of Longitudinal Testing 21

   23. No Discontinuities 22

   24. Discontinuity 22

   25. Incomplete Fusion of Backing Bar 22

   26. Eddy Current Weld Examination 23

   27. Encircling Coil for the Eddy Current Examination of Welded Pipe 24

   28. Typical Eddy Current Surface Prods for the Examination of Welds 25

B1 Standard Location of Elements Guide for the Nondestructive Examination of Welds 32

vi

AWD B1.10:1999

Guide for the Nondestructive Examination of Welds

1. General

   1. Scope. This standard provides a reference guide for the kinds of nondestructive examination methods that are used to verify that welds meet the requirements of a code or specification. The nondestructive examination meth- ods described are:

      1. Visual

      2. Penetrant

      3. Magnetic Particle

      4. Radiographic

      5. Ultrasonic

      6. Electromagnetic

      7. Leak

         The types of discontinuities detected with each method are disclosed and their causes discussed. Accep- tance criteria are not addressed in this standard. Such re- quirements may be in the application code. Requirements for nondestructive examination and acceptance criteria not provided in the application should be the specified in procurement documents prior the award of contracts.

         Nondestructive examination (NDE) is a general term used in this text to identify the common inspection meth- ods for evaluation of welds and related materials without destroying their usefulness.

         The terminology used in this guide is that established in AWS A3.0, Standard Welding Terms and Definitions. That document defines a discontinuity as “an interruption of the typical structure of a material, such as a lack of homogeneity in the mechanical, metallurgical, or physi- cal characteristics.” It defines discontinuity as a defect when it exceeds the sizes and types of discontinuities de- fined as rejectable by the applicable specification. For the purpose of this guide, reference will be made to detection of discontinuities without regard to the distinction be- tween acceptance or rejection.

         Principal factors to consider when choosing an in- spection method are the advantages and limitations of the

         
         

         method, anticipated type and size of discontinuity, accep- tance standards, and cost. Annex A is a guide to process selection.

         
         

   2. Advantages and Limitations of the Inspection Method. The advantages and limitations of the inspec- tion method help to determine which method(s) are best for detecting discontinuities of a particular size, shape, and orientation. For example, radiography can detect dis- continuities with major planes aligned parallel with the radiation beam, such as cracks oriented normal to plate surfaces. Radiography, however, usually cannot detect laminations in plate or cracks oriented parallel to the plate surface. Conversely, ultrasonic examination can de- tect cracks oriented in any direction provided the sound beam is oriented essentially perpendicular to the major axis of the crack.

      
      

   3. Acceptance Standards. The statement “the weld shall be radiographically examined” is incomplete unless acceptance standards are specified. Acceptance standards define characteristics of discontinuities and state whether particular types of discontinuities are allowed. Certain discontinuities such as slag or porosity are acceptable providing their size and distribution are within specified limits. These criteria have to be incorporated in the ac- ceptance standards. Most codes and specifications such as AWS D1.1, Structural Welding Code—Steel, ASME Boiler and Pressure Code, and API 1104, Welding of Pipeline and Related Facilities contain acceptance stan- dards. These and other construction standards are shown in Annex B.

      
      

   4. Cost. Costs of the various inspection methods de- pend on the particular situation. Two factors that should be considered in selection of a nondestructive examina- tion method are that of the equipment and of performing the inspection. Visual examination is usually the least

1