welding produces residual stresses and distortion, having detrimental effect on structure integrity and service performance of the welded pipe joints. this paper investigates residual stresses and distortion during gas metal arc welding (gmaw) of pipes of schedule 40 and 60, nominal diameter 100mm and 200mm and thickness 8mm and 10mm with ansi flanges of class 300#. welding parameters including...

Laser welding has been widely used in various industry fields. In order to further alter and broaden its applicability, a novel technology of laser welding under vacuum is introduced. The combination of high power laser and low ambient pressure provides an excellent welding performance and quality. In this paper, an overview on laser welding under vacuum is presented. It begins with a short int...

The visual recognition methods of texture feature of welding seam have the important significances to realize the automatic tracking of welding seam in the steps of subsequent welding and cover welding of multi-layer welding. Starting from the point of view of making full use of texture feature of welding seam image, the method research and algorithm design are respectively carried out on the 2...

–Friction stir welding is a solid state welding technology used for welding low melting point metals, such as Al, Mg and its alloys. Later welding was conducted on dissimilar metals which also produced a better defect free joint. Tool design and welding parameters contributes a major role for producing a better weld. Material flow and friction heat are the factors that the internal factor for t...

A new welding helmet for the manual welding process has been developed. The welders working conditions are improved by augmenting the visual information before and during welding. The image is improved providing a better view of the working area. An online quality assistant is available during welding, suggesting the correction of the guns position or pointing out welding errors, by analyzing t...

A robust process-controller was developed which maintains a fully penetrated weld. This feedback-controller is robust for various process disturbances that may occur, like variations in sheet thickness, welding velocity, focal position, shielding gas variations, etc. The signals from an optical sensor are used to design a so-called “switching” controller, which enables fully penetrated welding ...

This paper presents a new deposition process for directly building cylindrical parts of the 5356 aluminium alloy with variable polarity gas tungsten arc welding (VPGTAW). The relationship between the geometric sizes of the deposited layer and the welding parameters is investigated. A machine vision sensor is used to monitor and control the arc length that is a key welding parameter in the achie...

Magnetopneumography was used to measure non-invasively the concentration of the ferrimagnetic fraction of retained welding fume in the thoraces of steel arc welders. This was done by measuring the remanent magnetic fields due to ferrimagnetic particles. The 11 welders studied had concentrations of thoracic ferrimagnetic mineral several orders of magnitude greater than three machinists, 16 forme...

Fe-2.25Cr-1Mo a widely used material for headers and steam tubes of boilers. Welding of steam tube to header is required for production of boiler. Heat affected zone of the weld can have poor mechanical properties and poor corrosion behavior leading to weld failure. The cost of material used for steam tube and header of boiler should be controlled. This study propose a new materials design for ...

In order to study the effect of spot welding parameters such as welding force, welding time and welding current intensity on nugget formation and its size in resistance spot welding process of CR3 low carbon steel sheets using ANSYS commercial software package. A 2D axisymmetric electro-thermo-mechanical finite element (FE) model is developed to simulate the nugget forming process and to predic...