Structural Integrity. Volume 3

Transcription

1 Structural Integrity Volume 3 Series editors José A. F. O. Correia, Faculty of Engineering, University of Porto, Porto, Portugal Abílio M. P. De Jesus, Faculty of Engineering, University of Porto, Porto, Portugal Advisory editors Majid Reza Ayatollahi, Iran University of Science and Technology, Tehran, Iran Filippo Berto, Norwegian University of Science and Technology, Trondheim, Norway Hermes Carvalho, Federal University of Minas Gerais, Pampulha, Belo Horizonte, MG, Brazil Alfonso Fernández-Canteli, University of Oviedo, Gijón, Spain Matthew Hebdon, Virginia Tech, Blacksburg, USA Andrei Kotousov, University of Adelaide, Adelaide, Australia Grzegorz Lesiuk, Wroclaw University of Science and Technology, Wroclaw, Poland Yukitaka Murakami, Kyushu University, Fukuoka, Japan Shun-Peng Zhu, University of Electronic Science and Technology of China, Chengdu, Sichuan, China

2 The Structural Integrity book series is a high level academic and professional series publishing research on all areas of Structural Integrity. It promotes and expedites the dissemination of new research results and tutorial views in the structural integrity field. The Series publishes research monographs, professional books, handbooks, edited volumes and textbooks with worldwide distribution to engineers, researchers, educators, professionals and libraries. Topics of interested include but are not limited to: Structural integrity Structural durability Degradation and conservation of materials and structures Dynamic and seismic structural analysis Fatigue and fracture of materials and structures Risk analysis and safety of materials and structural mechanics Fracture Mechanics Damage mechanics Analytical and numerical simulation of materials and structures Computational mechanics Structural design methodology Experimental methods applied to structural integrity Multiaxial fatigue and complex loading effects of materials and structures Fatigue corrosion analysis Scale effects in the fatigue analysis of materials and structures Fatigue structural integrity Structural integrity in railway and highway systems Sustainable structural design Structural loads characterization Structural health monitoring Adhesives connections integrity Rock and soil structural integrity. More information about this series at

3 Jorge Luis González-Velázquez Fractography and Failure Analysis 123

4 Jorge Luis González-Velázquez Department of Engineering in Metallurgy and Materials Instituto Politécnico Nacional Mexico City Mexico ISSN X ISSN (electronic) Structural Integrity ISBN ISBN (ebook) Library of Congress Control Number: Springer International Publishing AG, part of Springer Nature 2018 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Printed on acid-free paper This Springer imprint is published by the registered company Springer International Publishing AG part of Springer Nature The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

5 Preface The study of fractured surfaces has been a fundamental part of materials research, practically since the formalization of the study of material mechanical behavior in the second half of the nineteenth century. Nevertheless, it was considered a minor specialty, usually subordinated to fracture mechanics until the post-second World War years, when high impact fractures involving mechanical and structural components, particularly in the aerospace industry, showed the usefulness of studying fractured surfaces. Since the introduction of the term Fractography by Carl A. Zapee at the 26th Annual Convention of ASM in 1944, it was recognized as a key discipline for scientific research and new material development. But it was not until the publication of the Metals Handbook, 8th Edition, Vol. 9 Fractography and Atlas of Fractography in 1974, by the American Society for Metals International (ASM), the leading organization in the publication of technical texts in the field of metallic materials for engineering use, that Fractography became a consolidated engineering specialty; likewise, the close relationship between fracture examination and failure analysis encouraged ASM to publish, in 1987, the Metals Handbook, Vol. 12, Fractography, the Metals Handbook, Vol. 11 Failure Analysis and Prevention, and the Metals Handbook, Vol. 19 Fatigue and Fracture, completing a series of handbooks related to fracture and material failure. The fracture and failure analysis Metals Handbooks of ASM are comprehensive compendiums of technical articles and numerous case studies, but their technical level is often very high, and the amount of information contained in them is difficult to process for those without previous experience in the area. This is the reason why, nowadays, the industrial and academic areas need a textbook that may be used for technical staff and students in their training for incursion into the fields of fracture studies and failure analysis. It is precisely this need that motivated me to write the book Fractography and Failure Analysis, with the intention of offering easy-to-read material, even for people with a basic knowledge of engineering, and to introduce the reader to the correct fracture examination methodology and to the performance of effective failure analysis of components whose failure is associated with fracture or cracking processes. v

6 vi Preface This book is the result of over 30 years of my own experience researching the mechanical behavior of metals, fracture mechanics, and structural integrity, as well as the performance of over 500 failure analyses of mechanical and structural components. The original text comes from the Fractography Notes that I wrote for my courses of Fractography and Failure Analysis that I have taught since 1992 at the graduate school of the Metallurgy and Materials Department of the Instituto Politecnico Nacional (National Polytechnic Institute) in Mexico City. For this reason, this book cites very few references, since all of the photographic and theoretical material is original. This book also completes my trilogy of books on mechanical behavior and fracture, the first two being Mechanical Metallurgy and Fracture Mechanics, both published in Spanish by Editorial Limusa, Mexico. Chapter 1 begins with a description of what, to my judgment, is the correct methodology for the examination of fractured physical components. This topic is introduced because of the nonexistence of a complete description of ASTM E2332 recommended practice for the examination of fractured components, so as to train young engineers, failure analysis apprentices, and novice fracture researchers, who usually make severe mistakes and errors in the interpretation of fractures, or worse, irreversibly alter the examined pieces, causing serious problems, especially when the examined item is part of a judicial investigation. For these reasons, this chapter describes the best practices for the examination and handling of fractures, including a practical guide for quality photography, cutting, cleaning, and preservation of fractures. The first chapter also includes a description of the making of fracture replicas, since these activities are an essential part of the fractographic examination. Chapter 2 presents the basic concepts for the scientific study of fractured surfaces, their classification, and a description of the main fracture lines and roughness that are visible to the naked eye. With this information, the reader will be able to determine the propagation sequence of a fracture, as well as identify the fracture mechanism and the effect of the stress state and mechanical properties on the fracture characteristics. Chapters 3, 4, and 5 focus on the study of brittle and ductile, fatigue and environmentally assisted fractures, starting with a description of the general characteristics of the fracture mechanisms and continuing with a description of fracture features of each mode of fracture at both the macroscopic and microscopic levels. The text is written in such a way that the reader will be able to learn how to identify the fractured surfaces and determine the factors that influence the fracture behavior. Occasionally, the topic sequence may vary from one chapter to another, in order to give clarity and logical sequence to the explanations contained herein. Chapter 6 is devoted exclusively to the description of a failure analysis procedure that I developed based on my own experience, but that is in accordance with the procedure described in ASTM E Investigation and Analysis of Physical Component Failures, nowadays the only internationally recognized practice for failure analysis of mechanical and structural components. This standard, however, only presents a list of the activities necessary to carry out a failure analysis, giving no explanation or description for the assorted steps (ASTM E standard consists of two pages). Therefore, in this chapter, the objectives

7 Preface vii and activities of a comprehensive failure analysis are described in detail. The explanation is complemented with recommendations and suggestions based on my experience in thousands of failure and fitness-for-service investigations of mechanical and structural components, practically in all fields of industry and in regard to all kinds of components, carried out in Mexico, several Latin American countries, the USA, and Europe. The chapter includes examples of failure analysis that illustrate the application of the procedure described in this chapter. It is worth mentioning that the decision to finish this book was a difficult one, because of the huge amount of case studies of fracture and failure analyses that come to me, almost every day, not to mention the fact that, as an author, the desire to include each new material example that comes to my attention is quite tempting. So, after giving it further thought, I decided to stick to the original idea of presenting a simple and accessible book to serve as a training and teaching tool for technicians, engineers, and scientists who are entering into the fracture and failure analysis fields for the first time. Mexico City, Mexico October 2017 Jorge Luis González-Velázquez

8 Contents 1 The Fractographic Examination Introduction Methodology of the Fractographic Examination Cleaning and Care of Fractures Fracture Handling Cutting of Fractured Pieces Fracture Cleaning Preservation of Fractures Photographing Fractures Replicas Elements of Fractography Classification of Fractures Mechanical Aspects of Fracture General Fracture Model Fracture Lines Types of Fracture Line Chevrons Beach Marks Ratchet Marks and Ridges Shear Lips Macroscopic Cleavage Multiple Cracking Microscopic Fractography Fracture Micromechanisms Brittle and Ductile Fractures Brittle Fracture Cleavage Quasi-Cleavage ix

9 x Contents Pseudo-Cleavage Cleavage in Amorphous Materials Intergranular Brittle Fractures Ductile Fractures Macroscopic Appearance of Ductile Fractures Ductile Fracture Mechanism Void Nucleation and Growth Mechanisms Ductile-Brittle Transition Ductile-Brittle Combined Fractures Fatigue Fracture General Aspects of Fatigue Fractography of Stage I Fatigue Macroscopic Characteristics of Stage I Fatigue Microscopic Characteristics of Stage I Fatigue Fatigue Crack Nucleation Mechanisms Fractography of Stage II Fatigue Macroscopic Characteristics of Stage II Fatigue Microscopic Characteristics of Stage II Fatigue Striation Formation Mechanisms Fractographic Characteristics of Stage II Fatigue Fracture in the Absence of Striations Corrosion-Fatigue Environmentally-Assisted Fracture General Aspects of Environmentally-Assisted Fracture Fundamentals of Metal Corrosion Stress Corrosion Cracking Mechanical Aspects of Stress Corrosion Cracking Characteristics of SCC Fractures SCC Mechanisms Creep Fracture General Aspects of Creep Fracture Creep Fracture Mechanism Creep Crack Growth Hydrogen-Induced Cracking Hydrogen-Induced Cracking Mechanism Fractography of Hydrogen-Induced Cracking Mechanical Aspects and Kinetics of Hydrogen-Induced Cracking Failure Analysis of Fractured Components Definitions of Failure Procedure for the Analysis of Mechanical Failures

10 Contents xi The ASTM E2332 Procedure Failure Analysis Ethics Failure Analysis Procedure of Fractured Components Failure Analysis and Fracture Mehanics Continuum Mechanics Yield Criteria Linear-Elastic Fracture Mechanics The Two-Parameter Criterion Relation Between Fractography and Fracture Mechanics Examples of Failure Analysis Failure of a Diesel Engine Fracture of a Cement Mill Reducer In-Service Rupture of a Gasoline Pipeline References