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Metallurgy and Mechanics of Welding

01 Jan 2008-
About: The article was published on 2008-01-01. It has received 42 citations till now. The article focuses on the topics: Welding.
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Journal ArticleDOI
TL;DR: In this article, the authors present an overview of the key factors related to the formation of defects in welding methods commonly used with aluminium alloys, such as friction-stir welding, laser beam welding and arc welding.
Abstract: Transportation industries are obliged to address concerns arising from greater emphasis on energy saving and ecologically sustainable products. Engineers, therefore, have a responsibility to deliver innovative solutions that will support environmental preservation and yet meet industries’ requirements for greater productivity and minimised operational costs. Aluminium alloys have successfully contributed to meeting the rising demand for lightweight structures. Notable developments in aluminium welding techniques have resolved many welding related problems, although some issues remain to be addressed. The present study attempts to give an overview of the key factors related to the formation of defects in welding methods commonly used with aluminium alloys. First, a concise overview of defects found in friction-stir welding, laser beam welding and arc welding of aluminium alloys is presented. The review is used as a basis for analysis of the relationship between friction-stir welding process parameters and weld defects. Next, the formation and prevention of the main weld defects in laser beam welding, such as porosity and hot cracking, are discussed. Finally, metallurgical aspects influencing weld metal microstructure and contributing to defects are tabulated, as are defect prevention methods, for the most common flaws in arc welding of aluminium alloys.

129 citations

Journal ArticleDOI
TL;DR: In this article, the current protective coating system technologies used to protect offshore wind power structures (OWS) as well as future perspectives are discussed, inspired by technological and scientific advances in recent years.
Abstract: Concerns over reducing CO2 emissions associated with the burning of fossil fuels in combination with an increase in worldwide energy demands is leading to increased development of renewable energies such as wind. The installation of offshore wind power structures (OWS) is one of the most promising approaches for the production of renewable energy. However, corrosion and fatigue damage in marine and offshore environments are major causes of primary steel strength degradation in OWS. Corrosion can reduce the thickness of structural components which may lead towards fatigue crack initiation and buckling. These failure mechanisms affect tower service life and may result in catastrophic structural failure. Additionally, environmental pollution stemming from corrosion’s by-products is possible. As a result, large financial investments are made yearly for both the prevention and recovery of these drawbacks. The corrosion rate of an OWS is dependent on different characteristics of attack which are influenced by access to oxygen and humidity. Structural degradation can occur due to chemical attack, abrasive action of waves, and microorganism attacks. Inspired by technological and scientific advances in recent years, the purpose of this paper is to discuss the current protective coating system technologies used to protect OWS as well as future perspectives.

76 citations


Cites background from "Metallurgy and Mechanics of Welding..."

  • ...Depth scratches parallel to the length of the weld should not be accepted by the inspector and a smooth transition between the weld and the metallic base is expected [80,83,209]....

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Journal ArticleDOI
TL;DR: In this paper, the effect of secondary austenite (γ2) on corrosion resistance of welded joints was investigated using optical microscopy and scanning electron microscopy, and the results were correlated with double loop electrochemical potentiodynamic reactivation (DL-EPR) and sulphide stress corrosion tests.

49 citations

Journal ArticleDOI
TL;DR: In this paper, Tungsten Inert Gas (TIG) welding process was used to obtain the optimum joint characteristics and minimize defects that will contribute to make the welding process more cost effective.

38 citations


Cites background from "Metallurgy and Mechanics of Welding..."

  • ...Hot cracking is so common in austenitic stainless steels where they are partially the only type of cracking the result of welding [6,7]....

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  • ...Selection suitable welding parameters and proper material is so important to control the mentioned problems [6,7]....

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Journal ArticleDOI
TL;DR: In this paper, the cold metal transfer (CMT) process is used for thin sheet metal products from stainless steel and aluminium by using a novel cold-metal transfer (cMT) method.
Abstract: For welding of conventional structural steels semiautomatic technologies (MIG, MAG) are widely used, whereas for welding of Al-alloys and stainless steels the TIG welding method is the most common. The current study concentrates on welding of thin sheet metal products from stainless steel and aluminium by using a novel cold metal transfer (CMT) process. The CMT technology is an alternative to TIG, providing advantages, such as reduction of distortions and increased productivity. This is mainly due to low heat input, achieved by controlled movement of the electrode. In order to realize these advantages, optimization of the CMT welding process is essential. The aim of this study was the optimization of the process using the existing welding equipment (robot, manipulator, etc) and validation of the CMT process. The limiting factors for the increase of the productivity are the reduction of quality (increase of porosity, distortions and inacceptable shape of the welding bed). As a result, practical recommendations are given for the implementation of the CMT technology for robotic welding.

29 citations