Arc welding

About: Arc welding is a research topic. Over the lifetime, 25393 publications have been published within this topic receiving 168182 citations.

Dual-spectrum digital imaging welding helmet

Abstract: Arc welding systems, methods, and apparatus that provide dual-spectrum, real-time viewable, enhanced user-discrimination between arc welding characteristics during an arc welding process. Welding headgear is configured to shield a user from harmful radiation and to include a digital camera or cameras to provide dual-spectrum (i.e., both visible spectrum and infrared spectrum) real-time digital video image frames. The welding headgear is also configured with an optical display assembly for displaying real-time digital video image frames to the user while wearing the headgear during an arc welding process. Image processing is performed on the visible and infrared spectrum video image frames to generate dual-spectrum video image frames providing an integrated and optimized view of both the visible and thermal characteristics of the arc welding process which can be viewed by the user on the optical display assembly in real time.

Microstructure and mechanical properties of aluminum 5083 weldments by gas tungsten arc and gas metal arc welding

Abstract: The mechanical properties and microstructural features of aluminum 5083 (AI5083) weldments processed by gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) are investigated. Weldments processed by both methods are mechanically softer than the parent material AI5083, and could be potential sites for plastic localization. It is revealed that AI5083 weldments processed by GTAW are mechanical more reliable than those by GMAW. The former bears higher strength, more ductility, and no apparent microstructure defects. Perceivable porosity in weldments by GMAW is found, which could account for the distinct mechanical properties between weldments processed by GTAW and GMAW. It is suggested that caution should be exercised when using GMAW for AI5083 in the high-speed-train industry where such light weight metal is broadly used.

Welding process impact on residual stress and distortion

Abstract: Residual stress and distortion continue to be important issues in shipbuilding and are still subject to large amounts of research. This paper demonstrates how the type of welding process influences the amount of distortion. Many shipyards currently use submerged arc welding (SAW) as their welding process of choice. In this manuscript, the authors compare welds made by SAW with DC gas metal arc welding, pulsed gas metal arc welding, Fronius cold metal transfer (CMT), autogenous laser and laser hybrid welding on butt welds in 4 mm thick DH36 ship plate. Laser and laser hybrid welding were found to produce the lowest distortion. Nevertheless, a considerable improvement can be achieved with the pulsed gas metal arc welding and CMT processes. The paper seeks to understand the relationship between heat input, fusion area, measured distortion and the residual stress predicted from a simple numerical model, and the residual stresses validated with experimental data.

Calculation of three-dimensional electromagnetic force field during arc welding

Abstract: Electromagnetic force is an important driving force for convection in the weld pool during arc welding. Accurate calculation of the electromagnetic force field requires complex numerical calculations of three-dimensional current density and magnetic flux fields. Several simplifying assumptions have been suggested to avoid the complex calculations. The resulting analytical expressions for the electromagnetic force field have been widely used without any critical evaluation of their intrinsic merit, since accurate numerical calculations were difficult in the past because of lack of fast computers. A numerical model has been developed to accurately calculate the current density and magnetic flux fields and the resulting electromagnetic force field in three dimensions in the entire weldment. The model can take into account any current distribution on the work piece surface and evaluate the effects of different arc locations and work piece geometry on the electromagnetic force field. Contributions of the electrode current, arc plasma, and current distribution inside the three-dimensional work piece to the magnetic field and the electromagnetic force field are determined. The electromagnetic force field computed from the model is compared with those obtained from the commonly used simplified expressions of electromagnetic force to examine the accuracy of the commonly used simplifying assumptions. The accuracy of the computed electromagnetic force field can be significantly improved by using the proposed numerical model.

The Effect of Gas Metal Arc Welding (GMAW) Processes on Different Welding Parameters

Abstract: Gas Metal Arc Welding (GMAW) process is leading in the development in arc welding process which is higher productivity and good in quality. In this study, the effects of different parameters on welding penetration, microstructural and hardness measurement in mild steel that having the 6 mm thickness of base metal by using the robotic gas metal arc welding are investigated. The variables that choose in this study are arc voltage, welding current and welding speed. The arc voltage and welding current were chosen as 22, 26 and 30 V and 90, 150 and 210 A respectively. The welding speed was chosen as 20, 40 and 60 cm/min. The penetration, microstructure and hardness were measured for each specimen after the welding process and the effect of it was studied. As a result, it obvious that increasing the parameters value of welding current increased the value of depth of penetration. Other than that, arc voltage and welding speed is another factor that influenced the value of depth of penetration. The microstructure shown the different grain boundaries of each parameters that affected of the welding parameters.