Weld Cracking In Ferrous Alloys

Weld cracks are unacceptable defects that can compromise the integrity of welded structures. Weld cracking can lead to structural failures which at best will require remedial action and at worst can lead to loss of life. Weld cracking in ferrous alloys reviews the latest developments in the design, evaluation, prevention and repair of weld cracks. Part one reviews the fundamentals as well as recent advances in the areas of welding technology, design and material selection for preventing weld cracking. Part two analyses weld crack behaviour, evaluation and repair of cracking/cracked welds. The book benefits from an extensive and robust chapter on the topic of NDE and quality control that was contributed by one of the most respected non-destructive evaluation and development groups in the world. Part three covers environment assisted weld cracking. With its distinguished editor and international team of contributors, Weld cracking in ferrous alloys is a valuable source of reference for all those concerned with improving the quality of welding and welded components. In the planning and development of this book, particular care has been taken to make the chapters suitable for people from other disciplines who need to understand weld cracking and failure. Reviews the latest developments in the design, evaluation, prevention and repair of weld cracks Assesses recent advances in welding technology, design and material selection Analyses weld crack behaviour, evaluation and repair including environment assisted weld cracking

Failure of welded components can occur during service as well as during fabrication. Most common, analyses of the resistance of welded components against failure are targeted at crack avoidance. Such evaluations are increasingly carried out by modern weldability studies, i. e. considering interactions between the selected base and filler materials, structural design and welding process. Such weldability investigations are particularly targeted to prevent hot cracking, as one of the most common cracking phenomena occurring during weld fabrication. To provide an international information and discussion platform to combat hot cracking, an international workshop on Hot Cracking Phenomena in Welds has been created, based on an initiative of the Institute for Materials and Joining Technology at the Otto-von-Guericke University in Magdeburg and the Division V. 5 – Safety of Joined Components at the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany. The first workshop was organized in Berlin under the topics mechanisms and phenomena, metallurgy and materials, modelling and simulations as well as testing and standardization. It consisted of 20 individual contributions from eight countries, which were compiled in a book that found a very ready market, not only in the welding community. As a consequence of increasing interest, it has been decided to establish the Workshop on Hot Cracking Phenomena in Welds as a regular event every three years embedded in the International Institute of Welding (IIW). Attached to the IIW Commission IX and II Spring intermediate meetings, the second workshop was organized in March 2007.

This book reviews the behaviour of metals and alloys during welding. In the first part the heat flow in arc welding processes is discussed. The weld thermal cycle is explained in terms of heat input, and the geometry of weld and thicknesses to be welded. The real welding cycle is described in terms of thermal and strain cycles. The weld metal is characterized in terms of fusion stage, absorption of gases and stage of metal crystallization and structural transformation. The metallurgical background of cracking is described by a full set of crackability tests along with the evaluation of metals from the point of view of crackability. Post welding heat treatment is reviewed, and includes the relaxation of stresses induced by welding. Guidelines are given for the selection of steels for welded structures. Several chapters examine the weldability of particular steels, including high strength steels, stainless steels, high alloyed steels, cryogenic steels and other metals and alloys. The theories are quantified in the form of calculations or computing programmes. Readers will find sufficent data for software processing.

Weldment cracking is a broad complex field. Even if one considers only cracking of steel weldments, the problems range from cracking at temperatures near the solidus during welding to cracking at room temperature days, weeks, or months after welding is completed. Numerous reports of investigations in this field are contained in the published and unpublished literature. However, most of these reports cover only a particular problem in a specific area of the broad field of weldment cracking. This review attempts to cover the major aspects of the entire field of weldment cracking. Necessarily, the review is for the most part general, only being specific in a few instances to illustrate a point. (Author).

This is the fourth volume in the well-established series of compendiums devoted to the subject of weld hot cracking. It contains the papers presented at the 4th International Cracking Workshop held in Berlin in April 2014. In the context of this workshop, the term “cracking” refers to hot cracking in the classical and previous sense, but also to cold cracking, stress-corrosion cracking and elevated temp. solid-state cracking. A variety of different cracking subjects are discussed, including test standards, crack prediction, weldability determination, crack mitigation, stress states, numerical modelling, and cracking mechanisms. Likewise, many different alloys were investigated such as aluminum alloys, copper-aluminum dissimilar metal, austenitic stainless steel, nickel base alloys, duplex stainless steel, creep resistant steel, and high strength steel.

Many new, or relatively new, welding processes such as friction stir welding, resistance spot welding and laser welding are being increasingly adopted to replace or improve on traditional welding techniques. Before advanced welding techniques are employed, their potential failure mechanisms should be well understood and their suitability for welding particular metals and alloys in different situations should be assessed. Failure mechanisms of advanced welding processes provides a critical analysis of advanced welding techniques and their potential failure mechanisms. The book contains chapters on the following topics: Mechanics modelling of spot welds under general loading conditions and applications to fatigue life predictions, Resistance spot weld failure mode and weld performance for aluminium alloys, dual phase steels and TRIP steels, Fatigue behaviour of spot welded joints in steel sheets, Non-destructive evaluation of spot weld quality, Solid state joining - fundamentals of friction stir welding, Failure mechanisms in friction stir welds, Microstructure characteristics and mechanical properties of laser weld bonding of magnesium alloy to aluminium alloy, Fatigue in laser welds, Weld metal ductility and its influence on formability of tailor welded blanks, Joining of lightweight materials using reactive nanofoils, and Fatigue life prediction and improvements for MIG welded advanced high strength steel weldments. With its distinguished editor and international team of contributors, Failure mechanisms of advanced welding processes is a standard reference text for anyone working in welding and the automotive, shipbuilding, oil and gas and other metal fabrication industries who use modern and advanced welding processes. Provides a critical analysis of advanced welding techniques and their potential failure mechanisms Experts in the field survey a range of welding processes and examine reactions under various types of loading conditions Examines the current state of fatigue life prediction of welded materials and structures in the context of spot welded joints and non-destructive evaluation of quality

Although the avoidance of hot cracking still represents a major topic in modern fabrication welding components, the phenomena have not yet been fully understood. Through the 20 individual contributions from experts all over the world the present state of knowledge about hot cracking during welding is defined, and the subject is approached from four different viewpoints. The first chapter provides an overview of the various hot cracking phenomena. Different mechanisms of solidification cracking proposed in the past decades are summarized and new insight is particularly given into the mechanism of ductility dip cracking. The effects of different alloying elements on the hot cracking resistance of various materials are shown in the second chapter and, as a special metallurgical effect, the initiation of stress corrosion cracking at hot cracks has been highlighted. The third chapter outlines how numerical analyses and other modelling techniques can be utilized to describe hot cracking phenomena and how such results might contribute to the explanation of the mechanisms. Various hot cracking test procedures are presented in the final chapter with a special emphasis on standardization. For the engineering and natural scientists in research and development the book provides both, new insight and a comprehensive overview of hot cracking phenomena in welds. The contributions additionally give numerous individual solutions and helpful advice for international welding engineers to avoid hot cracking in practice. Furthermore, it represents a very helpful tool for upper level metallurgical and mechanical engineering students.

Describes the weldability aspects of structural materials used in a wide variety of engineering structures, including steels, stainless steels, Ni-base alloys, and Al-base alloys Welding Metallurgy and Weldability describes weld failure mechanisms associated with either fabrication or service, and failure mechanisms related to microstructure of the weldment. Weldability issues are divided into fabrication and service related failures; early chapters address hot cracking, warm (solid-state) cracking, and cold cracking that occur during initial fabrication, or repair. Guidance on failure analysis is also provided, along with examples of SEM fractography that will aid in determining failure mechanisms. Welding Metallurgy and Weldability examines a number of weldability testing techniques that can be used to quantify susceptibility to various forms of weld cracking. Describes the mechanisms of weldability along with methods to improve weldability Includes an introduction to weldability testing and techniques, including strain-to-fracture and Varestraint tests Chapters are illustrated with practical examples based on 30 plus years of experience in the field Illustrating the weldability aspects of structural materials used in a wide variety of engineering structures, Welding Metallurgy and Weldability provides engineers and students with the information needed to understand the basic concepts of welding metallurgy and to interpret the failures in welded components.