Gas metal arc welding

About: Gas metal arc welding is a research topic. Over the lifetime, 11706 publications have been published within this topic receiving 109555 citations. The topic is also known as: metal active gas welding & GMAW.

Optimization of Gas Metal Arc Welding Process Parameters Using Standard Deviation (SDV) and Multi-Objective Optimization on the Basis of Ratio Analysis (MOORA)

Abstract: Welding technology is very vital for the industrial development and technological advancement of any country. In this regard achieving good quality machine manufactured products cannot be over emphasized. Since welding is a very reliable method of joining metals together permanently, several methodologies have been adopted to improve the quality of weldments, such as the neural network, fuzzy logic, surface response methodology, full factorial method, and so on. In this case, the multi-objective optimization on the basis of ratio analysis (MOORA) is applied. MOORA is used to solve multi-criteria (objective) optimization problem in welding. MOORA in combination with standard deviation (SDV) was used for the optimization process. SDV was used to determine the weights that were used for normalizing the responses obtained from the mechanical test results. From applying the SDV-MOORA method, it was found that welding current of 350 A, welding voltage of 22 V, an electrode diameter of 3.2 mm and welding speed of 100 mm/s produced the weldment with the best mechanical properties. The mechanical properties compare very well with those obtained from other literature. It is, therefore, concluded that the SDV-MOORA method has successfully optimized the welding process parameters used in this study.

The characteristic of twin-electrode TIG coupling arc pressure

Abstract: The coupling arc of twin-electrode TIG (T-TIG) is a particular kind of arc, which is achieved through the coupling of two arcs generated from two insulated electrodes in the same welding torch. It is therefore different from the single arc of conventional TIG in its physical characteristics. This paper studies the distribution of T-TIG coupling arc pressure, and analyses the influences of welding current, arc length, the distance between electrode tips and electrode shape upon arc pressure on the basis of experiment. It is expected that the T-TIG welding method can be applied in high efficiency welding according to its low arc pressure.

Calorimetric Measurement of Droplet Temperature in GMAW

Abstract: Average temperature was calculated from calorimetric measurements in free-flight gas metal arc welding (GMAW) for ER70S-6 (carbon steel), ER316L (stainless steel), and ER4030 (aluminum) electrodes. Measurements were conducted using a constant-pressure water calorimeter to capture the droplets and a flow-through copper cathode/calorimeter to carry the arc. Thermocouples were used to monitor the temperature change of the water flowing through the cathode as well as in the constant pressure calorimeter. Results show a local minimum in temperature during the transition from globular to spray transfer modes.

New Findings On The Efficiency Of Gas Shielded Arc Welding

Abstract: A study was carried out to measure the effective efficiency of different gas shielded arc welding processes and investigate the role of influence coefficients on the process efficiency. A new system to measure the integrated heat flow in welding processes was developed and further investigated. By this system, it can be shown how e.g. electrical and welding torch parameters, as well as material and gas parameters directly influence the efficiency of the welding process. Through this, it is possible to raise the efficiency of welding (processes for example by reducing the wire speed, using helium gas or increasing the distance of the welding torch to the metal plate. Contrary, increasing the current, welding speed or voltage reduces the process efficiency. The difference between the lowest and highest achievable value of efficiency can be more than 15 % for one specific welding process. In addition to the conventional welding processes like gas tungsten arc welding (GTAW), gas metal arc welding (GMAW) and plasma welding also latest technologies, such as heat reduced processes (for example controlled dip arc with or without wire pullback) and high performance welding processes were analysed. In this manuscript, primarily the new technology for measuring the efficiency is presented. Furthermore, different influence coefficients and their effects on the overall efficiency of welding processes are described. Finally, the differences between measured efficiencies and fixed values of efficiencies for welding processes given in standards are discussed. The efficiencies of the latest heat reduced and high performance welding processes are given. The results verify that the parametrical influence on the efficiency of welding processes is huge, so that it is not recommended to work with fixed efficiency values for example in modeling and simulation.