Download or read book Thermal Analysis and Microhardness Mapping in Hybrid Laser Welds in a Structural Steel written by E. A. Metzbower and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid welding, the combination of laser and arc welding, is being heavily investigated for potential applications in the fabrication of structural steel components. The hybrid process is an alternative to autogenous laser welding that requires good fit-up of the parts. With the hybrid process, the addition of filler metal alters the weld pass chemistry and fills any gaps that may occur. In some applications, the fit-up of parts is only part of the issue for laser welding. In some structural steel components, the chemistry of the base metal when autogenously laser welded can result in weldments (weld metal and heat-affected zone (HAZ)) that have high hardness values. This indirectly indicates that the weld metal is brittle and not suitable for certain applications. The hardness values of the weldment have been used as an acceptance criteria for certain industrial applications. The use of hybrid welding may address the hardness issue. The addition of filler metal through a gas metal arc (GMAW) based hybrid process decrease the cooling rate in the HAZ therefore improving mechanical properties. These improvements can often be detected by microhardness profiles. While traditional hardness profiles tabulate hardness in a few regions of the weld, hardness mapping better profiles the hardness trends in the weldment. This paper will present welding results for the hybrid structural welding of a structural carbon steel using a 4 kW Nd:YAG based hybrid laser system. The data will center on the thermal response of the steel to the welding process, on the hardness mapping of the weldments and how the heat input altered the hardness and the mechanical properties of the welds.

Download or read book THERMEC 2003 written by Tetsuo Sakai and published by . This book was released on 2003 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hybrid Laser Arc Welding written by F O Olsen and published by Elsevier. This book was released on 2009-06-26 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications.The first part of the book reviews the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part two discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship building and the automotive industry.With its distinguished editor and international team of contributors, Hybrid laser-arc welding is a valuable source of reference for all those using this important welding technology. - Reviews arc and laser welding including both advantages and disadvantages of the hybrid laser-arc approach - Explores the characteristics of the process including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality - Examines applications of the process including magnesium alloys, aluminium and steel with specific focus on applications in the shipbuilding and automotive industries

Download or read book Welding Journal written by and published by . This book was released on 2009 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Joining of Polymer Metal Hybrid Structures written by Sergio T. Amancio Filho and published by John Wiley & Sons. This book was released on 2018-02-06 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive introduction to the concepts of joining technologies for hybrid structures This book introduces the concepts of joining technology for polymer-metal hybrid structures by addressing current and new joining methods. This is achieved by using a balanced approach focusing on the scientific features (structural, physical, chemical, and metallurgical/polymer science phenomena) and engineering properties (mechanical performance, design, applications, etc.) of the currently available and new joining processes. It covers such topics as mechanical fastening, adhesive bonding, advanced joining methods, and statistical analysis in joining technology. Joining of Polymer-Metal Hybrid Structures: Principles and Applications is structured by joining principles, in adhesion-based, mechanical fastened, and direct-assembly methods. The book discusses such recent technologies as friction riveting, friction spot joining and ultrasonic joining. This is used for applications where the original base material characteristics must remain unchanged. Additional sections cover the main principles of statistical analysis in joining technology (illustrated with examples from the field of polymer-metal joining). Joining methods discussed include mechanical fastening (bolting, screwing, riveting, hinges, and fits of polymers and composites), adhesive bonding, and other advanced joining methods (friction staking, laser welding, induction welding, etc.). Provides a combined engineering and scientific approach used to describe principles, properties, and applications of polymer-metal hybrid joints Describes the current developments in design of experiments and statistical analysis in joining technology with emphasis on joining of polymer-metal hybrid structures Covers recent innovations in joining technology of polymer-metal hybrid joints including friction riveting, friction spot joining, friction staking, and ultrasonic joining Principles illustrated by pictures, 3D-schemes, charts, and drawings using examples from the field of polymer-metal joining Joining of Polymer-Metal Hybrid Structures: Principles and Applications will appeal to chemical, polymer, materials, metallurgical, composites, mechanical, process, product, and welding engineers, scientists and students, technicians, and joining process professionals.

Download or read book Kinetics of Carbide Precipitation During Laser Beam Welding of Dual phase and Martensitic Steels written by Dulal Chandra Saha and published by . This book was released on 2016 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to ensure a high passenger safety and reduce greenhouse gas emissions, dual-phase (DP) and martensitic steels (MS) are increasingly being used in the automotive industries. However, the main issue in the welding of steels containing a metastable martensite phase is softening, which occurs in the sub-critical heat affected zone (SCHAZ) and deteriorates joint integrity. This work attempts to understand the martensite tempering kinetics involved during high-speed laser beam welding where steels are exposed to the rapid heating and cooling cycles. Fiber laser welding was performed on DP steel and its dissimilar combination with high strength low alloy (HSLA) steel. Different zones that produced at heat affected zone (HAZ) were characterized with respect to microstructure, micro- and nano-hardness, and tensile testing. Microstructural characterization suggests that the as-received martensite phase decomposes in the SCHAZ and forms various shapes and sizes of carbides, which reduces the local microhardness of the steel and subsequently the sample fractured in this zone during tensile loading. In addition, the chemical composition and microstructure of DP steel plays an important role in the tempering reaction kinetics. The study conducted on the DP780 steel composed of ferrite, martensite, and bainite microconstituents, exhibited increasing microhardness in the HAZ instead of softening. This phenomenon is referred to as “secondary hardening”. Rapid isothermal tempering conducted in a Gleeble simulator also indicated occurrence of secondary hardening at 500°C, as confirmed by plotting the tempered microhardness against the Holloman-Jaffe parameter. The mechanism of secondary hardening in this kind of a steel was unveiled by advanced characterization techniques carried out using transmission electron microscopy (TEM) with high-angle annular dark-field (HAADF) imaging. The experimental results suggested that the cementite (Fe3C) and TiC phases located in the bainite phase of DP780 steel decomposed upon rapid tempering to form needle-shaped Mo2C and plate-shaped M4C3 carbides giving rise to secondary hardening. In order to investigate the influences of steel microstructure on the martensite tempering kinetics two commercially produced DP980 grade steels were used. The study suggests that the severity of martensite tempering can be avoided by modifying the microstructure of the steels; the DP980 steel produced with a combination of martensite, ferrite, and a blocky retained austenite phase promotes high tensile strength of the laser welded joint similar to the un-welded material. Strength of the tempered martensite significantly differed depending on the nature of the tempering mode and heat input. Therefore, tempered martensite obtained from four different tempering modes was investigated. Extensive recovery and reduction of boundary regions was identified on the structure tempered slowly, whereas rapidly tempered structures retained a high density of dislocations and less decomposition of the lath structure. The study revealed that dislocation density has a prominent effect on the macroscopic strength of the tempered martensite over all other strength contributors. In addition, rapid thermal cycles retained a high density of dislocations after tempering thus improving the tempered martensite strength. Therefore, the combined effect of dislocation density and the rapid thermal cycle was investigated by deforming the martensitic sheets to different levels of plastic deformation and subsequently tempering using conventional furnace tempering and the laser beam welding. It was found that the increased dislocation density due to the plastic deformation caused more nucleation sites for cementite precipitation, short-range carbon diffusion, and shorter growth period of cementite. The morphologies of the cementite were changed from elongated to small quasi-spherical when the sheet was plastically deformed. The deformed and tempered martensite yielded higher microhardness resulting from finer and semicoherent precipitates, a high density of retained dislocation density, and the presence of untempered and partially tempered martensite blocks. The thermal analysis of martensite tempering carried out using a dilatometer suggests that the carbide precipitation temperature range increases to the higher tempering temperature when the sheet was subjected to rapid thermal cycles. Finally, a microstructural based model was applied to predict the yield strength and microhardness of the tempered martensite by incorporating the effects of heating rate, tempering temperature, and time. Experimental and modelling results suggest that the faster tempering mode in combination with a very short tempering duration provides the highest tempered martensite strength.

Download or read book Hybrid Laser Welding in API X65 and X70 Steels written by Andrês Fabricio Fischdick Acuña and published by . This book was released on 2016 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid laser welding presents an important advance in productivity due to high welding speeds. However, fast cooling rates are inherent to the process, affecting the resultant microstructures and joint performance. In this research, three API steels were welded using hybrid laser welding with three distinct preheating conditions. The specimens, which were obtained using one hybrid laser root pass and two other GMAW filling passes, were subjected to microstructural characterization and performance evaluation using hardness and toughness measurements. Incomplete joints with only the hybrid root pass and completed joints (root and filling passes) were evaluated. Hardness mapping revealed as the critical area the top portion of hybrid laser fusion zone, which was subsequently reheated by the GMAW filling pass. Optical and scanning electron microscopy revealed a bainitic-martensitic microstructure with the proportion of those two phases varying as a function of the preheating. Miniaturized Charpy V-notch testing was used to evaluate the local toughness and ductile-to-brittle transition of several regions within the joint. Fractographic analysis confirmed the abrupt transition from ductile-to-brittle behavior. The localized fracture toughness testing showed an adequate joint performance for all tested conditions. Nevertheless, the hardness values meet the requirements only for higher preheating temperature conditions.

Download or read book Laser Assisted Fabrication of Materials written by Jyotsna Dutta Majumdar and published by Springer Science & Business Media. This book was released on 2012-11-03 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser assisted fabrication involves shaping of materials using laser as a source of heat. It can be achieved by removal of materials (laser assisted cutting, drilling, etc.), deformation (bending, extrusion), joining (welding, soldering) and addition of materials (surface cladding or direct laser cladding). This book on ́Laser assisted Fabrication’ is aimed at developing in-depth engineering concepts on various laser assisted macro and micro-fabrication techniques with the focus on application and a review of the engineering background of different micro/macro-fabrication techniques, thermal history of the treated zone and microstructural development and evolution of properties of the treated zone.

Download or read book Resistance Welding written by Hongyan Zhang and published by CRC Press. This book was released on 2011-12-13 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drawing on state-of-the-art research results, Resistance Welding: Fundamentals and Applications, Second Edition systematically presents fundamental aspects of important processes in resistance welding and discusses their implications on real-world welding applications. This updated edition describes progress made in resistance welding research and

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1982 with total page 1282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Manufacturing and Application of Stainless Steels written by Andrea Di Schino and published by MDPI. This book was released on 2020-04-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stainless steels represent a quite interesting material family, both from a scientific and commercial point of view, following to their excellent combination in terms of strength and ductility together with corrosion resistance. Thanks to such properties, stainless steels have been indispensable for the technological progress during the last century and their annual consumption increased faster than other materials. They find application in all these fields requiring good corrosion resistance together with ability to be worked into complex geometries. Despite to their diffusion as a consolidated materials, many research fields are active regarding the possibility to increase stainless steels mechanical properties and corrosion resistance by grain refinement or by alloying by interstitial elements. At the same time innovations are coming from the manufacturing process of such a family of materials, also including the possibility to manufacture them starting from metals powder for 3D printing. The Special Issue scope embraces interdisciplinary work covering physical metallurgy and processes, reporting about experimental and theoretical progress concerning microstructural evolution during processing, microstructure-properties relations, applications including automotive, energy and structural.

Download or read book Computational Welding Mechanics written by John A. Goldak and published by Springer Science & Business Media. This book was released on 2006-07-04 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Welding Mechanics (CWM) provides readers with a complete introduction to the principles and applications of computational welding including coverage of the methods engineers and designers are using in computational welding mechanics to predict distortion and residual stress in welded structures, thereby creating safer, more reliable and lower cost structures. Drawing upon years of practical experience and the study of computational welding mechanics the authors instruct the reader how to: - understand and interpret computer simulation and virtual welding techniques including an in depth analysis of heat flow during welding, microstructure evolution and distortion analysis and fracture of welded structures, - relate CWM to the processes of design, build, inspect, regulate, operate and maintain welded structures, - apply computational welding mechanics to industries such as ship building, natural gas and automobile manufacturing. Ideally suited for practicing engineers and engineering students, Computational Welding Mechanics is a must-have book for understanding welded structures and recent technological advances in welding, and it provides a unified summary of recent research results contributed by other researchers.

Download or read book Welding Metallurgy written by Sindo Kou and published by John Wiley & Sons. This book was released on 2003-03-31 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Updated to include new technological advancements in welding Uses illustrations and diagrams to explain metallurgical phenomena Features exercises and examples An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.

Download or read book Welding and Joining of Advanced High Strength Steels AHSS written by Mahadev Shome and published by Elsevier. This book was released on 2015-02-25 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Welding and Joining of Advanced High Strength Steels (AHSS): The Automotive Industry discusses the ways advanced high strength steels (AHSS) are key to weight reduction in sectors such as automotive engineering. It includes a discussion on how welding can alter the microstructure in the heat affected zone, producing either excessive hardening or softening, and how these local changes create potential weaknesses that can lead to failure. This text reviews the range of welding and other joining technologies for AHSS and how they can be best used to maximize the potential of AHSS. - Reviews the properties and manufacturing techniques of advanced high strength steels (AHSS) - Examines welding processes, performance, and fatigue in AHSS - Focuses on AHSS welding and joining within the automotive industry

Download or read book Laser Welding written by João Pedro Oliveira and published by MDPI. This book was released on 2020-05-13 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser welding is a high-energy process used in a wide range of advanced materials to obtain micro- to macro-sized joints in both similar and dissimilar combinations. Moreover, this technique is widely used in several industries, such as automotive, aerospace, and medical industries, as well as in electrical devices. Although laser welding has been used for several decades, significant and exciting innovations often arise from both the process and/or advanced materials side.

Download or read book GaN AIN InN and their Alloys Volume 831 written by Christian Wetzel and published by Cambridge University Press. This book was released on 2005-07-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses GaN and Related Alloys and reflects an emerging emphasis on the binaries of InN and AlN. The major thrust here is the topical development of thin-film growth, bulk growth techniques, methods to cover the full ternary and quaternary alloy ranges toward InN and AlN and their characterization; strategies for structural defect reduction and their characterization; ways to better control p-type doping and its characterization; device and defect physics, including polarization effects; physics of surfaces and interfaces; and device processing techniques. In addition, advances in MBE devices, high-power electronics, RF performance of electronics, UV emitters, high-efficiency light emitters, photo and chemical sensors, as well as new applications within the group-III nitrides, are also covered. The book captures the current status of this field and will be useful for researchers working with group-III nitrides, as well as for students who seek entry into this subject.

Download or read book Laser Processing of Engineering Materials written by John Ion and published by Elsevier. This book was released on 2005-03-22 with total page 589 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complete guide to understanding and using lasers in material processing!Lasers are now an integral part of modern society, providing extraordinary opportunities for innovation in an ever-widening range of material processing and manufacturing applications. The study of laser material processing is a core element of many materials and manufacturing courses at undergraduate and postgraduate level. As a consequence, there is now a vast amount of research on the theory and application of lasers to be absorbed by students, industrial researchers, practising engineers and production managers. Written by an acknowledged expert in the field with over twenty years' experience in laser processing, John Ion distils cutting-edge information and research into a single key text. Essential for anyone studying or working with lasers, Laser Processing of Engineering Materials provides a clear explanation of the underlying principles, including physics, chemistry and materials science, along with a framework of available laser processes and their distinguishing features and variables. This book delivers the knowledge needed to understand and apply lasers to the processing of engineering materials, and is highly recommended as a valuable guide to this revolutionary manufacturing technology. The first single volume text that treats this core engineering subject in a systematic manner Covers the principles, practice and application of lasers in all contemporary industrial processes; packed with examples, materials data and analysis, and modelling techniques