TRAINING COURSE SERIES No. 11 Liquid Penetrant and Magnetic Particle Testing at Level 2 Manual for the Syllabi Contained in IAEA-TECDOC-628, “Training Guidelines in Non-destructive Testing Techniques” INTERNATIONAL ATOMIC ENERGY AGENCY, 2000 The originating Section of this publication in the IAEA was: Industrial Applications and Chemistry Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 A-1400 Vienna, Austria LIQUID PENETRANT AND MAGNETIC PARTICLE TESTING AT LEVEL 2 IAEA, VIENNA, 2000 IAEA-TCS-11 © IAEA, 2000 Printed by the IAEA in Austria February 2000 FOREWORD The International Atomic Energy Agency (IAEA) has been active in the promotion of non- destructive testing (NDT) technology in the world for many decades. The prime reason for this interest has been the need for stringent standards for quality control for safe operation of industrial as well a nuclear installations. It has successfully executed a number of programmes and regional projects of which NDT was an important part. Through these programmes a large number of persons have been trained in the member states and a state of self sufficiency in this area of technology has been achieved in many of them. All along there has been a realization of the need to have well established training guidelines and related books in order, firstly, to guide the IAEA experts who were involved in this training programme and, secondly, to achieve some level of international uniformity and harmonization of training materials and consequent competence of personnel. The syllabi for training courses have been published in the form of two TECDOC publications. The first was IAEA-TECDOC-407 which contained syllabi for the basic five methods, i.e. liquid penetrant testing, magnetic particle testing, eddy current testing, radiographic testing and ultrasonic testing, and the second and revised is IAEA-TECDOC-628 which includes additional methods of visual testing and leak testing. IAEA-TECDOC-628, as well as most of the international standards on the subject of training and certification of NDT personnel including ISO 9712, define three levels of competence, namely, Level 1, Level 2 and Level 3. Among these, Level 1 is the lowest and Level 3 the highest. The intermediate Level 2 is considered to be the most appropriate for persons who, beside other duties, are expected to independently undertake practical testing in the relevant method of NDT; develop NDT procedures adapted to various problems; prepare written instructions; make accept/reject decisions in accordance with relevant standards and specifications; be able to train and supervise the Level 1 staff under them and organize and report NDT results. The next logical step is to compile the textbooks and training manuals in accordance with these syllabi. Work in this regard has been undertaken and the manuals on radiographic testing and ultrasonic testing have already been issued in 1992 and 1999, respectively, in the Training Course Series. Compilation of this book is a continuation of that effort. These methods, in spite of their apparent simplicity, are the most widely used NDT methods to determine surface discontinuities, even in the most sophisticated of industries, including the nuclear and aerospace industries. The first draft of the book was put together by a group of consultants from Canada, Germany, India, Spain and Romania. It was reviewed by the National Centre for Non-destructive Testing (NCNDT) in Pakistan to bring it as close as possible to the syllabus requirements of IAEA- TECDOC-628. This has been done by putting in additional material wherever needed and then rearranging the whole in accordance with the format of Level 2 Surface Method Testing syllabi in IAEA-TECDOC-628. The section on materials, manufacturing processes and defects, which is common to all the NDT methods, has been adapted from the previous publications in the Training Course Series on Level 2 Radiographic and Ultrasonic Testing. An extensive bibliography at the end covers all the publications which were used in the compilation as well as those which can be consulted for furthering the knowledge of testing of materials using surface methods. The IAEA wishes to express its appreciation to all those who contributed to the production of these Training Course Notes and to the governments and organizations whose financial and technical support made this publication possible. The IAEA officer responsible for this publication was A.A. Khan of the Division of Physical and Chemical Sciences. EDITORIAL NOTE The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. CONTENTS 1. GENERAL KNOWLEDGE ............................................................................................. 1 1.1. Basic principles of non-destructive testing (NDT)................................................ 1 1.1.1. Definition and importance of NDT ........................................................... 1 1.1.2. Types of NDT methods............................................................................. 1 1.1.3. Visual testing (VT).................................................................................... 2 1.1.4. Liquid penetrant testing (PT) .................................................................... 3 1.1.5. Magnetic particle testing (MT) ................................................................. 5 1.1.6. Eddy current testing (ET).......................................................................... 7 1.1.7. Radiographic testing method (RT).......................................................... 10 1.1.8. Ultrasonic testing (UT)............................................................................ 14 1.1.9. Comparison of different NDT methods .................................................. 16 1.2. Materials and defects........................................................................................... 16 1.2.1. Structure of metals and alloys ................................................................. 16 1.2.2. Properties of materials (metallic & non-metallic)................................... 23 1.2.3. Discontinuities and defects in metallic materials.................................... 27 1.3. Processing and defects......................................................................................... 28 1.3.1. Primary processes and related defects..................................................... 28 1.3.2. Manufacturing processes and related defects.......................................... 42 1.4. Materials in service.............................................................................................. 80 1.4.1. Behaviour of materials in service............................................................ 80 1.4.2. Conditions leading to defects and failures .............................................. 80 1.4.3. Concepts of rupture development in metals............................................ 88 1.5. Quality and standardization................................................................................. 88 1.5.1. Quality..................................................................................................... 88 1.5.2. Quality control......................................................................................... 89 1.5.3. Quality assurance .................................................................................... 89 1.5.4. Examination and testing.......................................................................... 89 1.5.5. Inspection ................................................................................................ 90 1.5.6. Process of standardization....................................................................... 90 1.5.7. Guides and recommended practices........................................................ 90 1.5.8. Standards................................................................................................. 90 1.5.9. Codes and specifications ......................................................................... 91 1.5.10. Procedure................................................................................................. 91 1.5.11. Protocols.................................................................................................. 91 1.5.12. Report...................................................................................................... 91 1.5.13. Records.................................................................................................... 91 1.5.14. Development of a quality system ............................................................ 91 2. PHYSICAL PRINCIPLES OF THE TEST (PT) ............................................................ 97 2.1. General description of the method ...................................................................... 97 2.2. Properties of liquid penetrants............................................................................. 97 2.2.1. Viscosity.................................................................................................. 97 2.2.2. Surface tension.......................................................................................