Hot Cracking Phenomena in Welds II

ISBN-13: 9783540786276 / Angielski / Twarda / 2008 / 467 str.

Opis

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."

Spis treści

Solidification Cracking Theory.- In Search of the Prediction of Hot Cracking in Aluminium Alloys.- Application of the Rappaz-Drezet-Gremaud Hot Tearing Criterion to Welding of Aluminium Alloys.- Weld Solidification Cracking: Critical Conditions for Crack Initiation and Growth.- Consideration of the Welding Process as a Thermo-Physical Mechanism to Control Cracking in Weldments.- Determination of Critical Strain Rate for Solidification Cracking by Numerical Simulation.- Solidification Cracking of Ferrous and Nickel-Base Alloys.- Classification and Mechanisms of Cracking in Welding High-Alloy Steels and Nickel Alloys in Brittle Temperature Ranges.- Submerged Arc Welding – A Test for Centreline Cracking.- Influence of Local Weld Deformation on the Solidification Cracking Susceptibility of a Fully Austenitic Stainless Steel.- Weld Solidification Cracking in Solid-Solution Strengthened Ni-Base Filler Metals.- Hot Cracking Susceptibility of Ni-Base Alloy Dissimilar Metal Welds.- Evaluation of Weld Solidification Cracking in Ni-Base Superalloys Using the Cast Pin Tear Test.- SAW Cold Wire Technology – Economic Alternative for Joining Hot Crack Sensitive Nickel-Base Alloys.- Solidification Cracking of Aluminium Alloys.- Hot Tearing During Laser Butt Welding of 6xxx Aluminium Alloys: Process Optimisation and 2D/3D Characterisation of Hot Tears.- The Integral Approach – a Tailored Method to Optimize Structural Behavior and Weldability.- Weld Parameter and Minor Element Effects on Solidification Crack Initiation in Aluminium.- Using Simulation for Investigations of Hot Cracking Phenomena in Resistance Spot Welding of 6xxx Aluminum Alloys (AA6016 and AA6181).- Liquation Cracking.- Evaluating Hot Cracking Susceptibility of Ni-Base SAW Consumables for Welding of 9% Ni Steel.- Assessment of HAZ Hot Cracking in a High Nitrogen Stainless Steel.- Crack Appearance in Hot Rolled Billets.- Ductility-Dip Cracking.- Effect of Filler Metal La Additions on Micro-Cracking in Multi-Pass Laser Overlay Weld Metal of Alloy 690.- Ductility-Dip Cracking in High Chromium, Ni-Base Filler Metals.- Thermodynamic and Kinetic Approach to Ductility-Dip Cracking Resistance Improvement of Ni-base Alloy ERNiCrFe-7: Effect of Ti and Nb Additions.

Blurb

This is the second in a series of compendiums devoted to weld hot cracking phenomena, where this subject has been further scrutinized, bringing to bare the most current thoughts on this complex and diverse subject. With 22 technical papers in total, this book is divided in such a way that specific classifications of hot cracks are examined in detail, including solidification, liquation, and ductility dip cracking. The first chapter looks at solidification cracking theory, applying the most modern approaches to modelling weld solidification. Also provided here is a comprehensive review of cracking models. This is followed by two chapters characterizing solidification cracking behaviour for specific alloy systems: ferrous plus nickel-based alloys and aluminium alloys, respectively. The fourth chapter considers liquation cracking in ferrous alloys, and the fifth examines ductility-dip cracking. For engineers and scientists involved in materials research and development, this book provides both new insight and a broad overview of hot cracking phenomena in welds. The contributions additionally give numerous individual solutions and helpful advice for welding engineers to avoid hot cracking in practice. Furthermore, this book can serve as a useful teaching aid for upper level metallurgical, welding and mechanical engineering students.