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.

Advantages of the Green Solid State FSW over the Conventional GMAW Process

Abstract: The present work is an experimental comparison between the friction stir welding (FSW) and the conventional gas metal arc welding (GMAW) in joining of Al alloys. Two sets of 3 mm thick aluminum strip pairs were friction stir welded in a regular butting joint configuration. Two rotational speeds of 1750 rpm and 2720 rpm were utilized to perform the FSW process. The axial force and the transverse speed were kept constant at 6.5 KN and 45 mm/min, respectively. Cylindrical tool shoulder and pin geometry were selected. Strip pairs of other similar sets were butt jointed using the conventional GMAW. The welding quality, power input, and macrostructure and microstructure of the butted joints were examined. The types of the fumes and the amount of the released gases were measured and compared. The results showed that the solid state FSW is green, environment-friendly, and of superior welding properties compared to the conventional GMAW.

Gas shielded arc welding of steel

Abstract: 1,127,257. Welding by fusion. AIR REDUCTION CO. Inc. 13 Dec., 1966 [20 Dec., 1965], No. 55719/66. Heading B3R. [Also in Division C7] In short circuiting arc welding steel the shielding gas is 1-15% carbon dioxide with either 40-60% argon, balance helium or 60-80% helium, balance argon. These ranges are based on the fact that within the above limits of carbon dioxide peak penetration occurs when approximately 50% argon or 70% helium is used. Positioned welding of low alloy steel is effected with a short circuiting frequency of 20-150 cycles per second, and the electrode is transversely oscillated at ¢ inch amplitude and 40 oscillations per minute. The welding electrodes may be 5% Ni, Cr, Mo, V steel or steels containing

Development of a Three-Dimensional Heat-Transfer Model for the Gas Tungsten Arc Welding Process Using the Finite Element Method Coupled with a Genetic Algorithm–Based Identification of Uncertain Input Parameters

Abstract: An accurate estimation of the temperature field in weld pool and its surrounding area is important for a priori determination of the weld-pool dimensions and the weld thermal cycles. A finite element–based three-dimensional (3-D) quasi-steady heat-transfer model is developed in the present work to compute temperature field in gas tungsten arc welding (GTAW) process. The numerical model considers temperature-dependent material properties and latent heat of melting and solidification. A novelty of the numerical model is that the welding heat source is considered in the form of an adaptive volumetric heat source that confirms to the size and the shape of the weld pool. The need to predefine the dimensions of the volumetric heat source is thus overcome. The numerical model is further integrated with a parent-centric recombination (PCX)–operated generalized generation gap (G3) model–based genetic algorithm to identify the magnitudes of process efficiency and arc radius that are usually unknown but required for the accurate estimation of the net heat input into the workpiece. The complete numerical model and the genetic algorithm–based optimization code are developed indigenously using an Intel Fortran Compiler. The integrated model is validated further with a number of experimentally measured weld dimensions in GTA-welded samples in stainless steels.

Numerical simulation of welding-induced distortion in thin-walled structures

Abstract: A sequentially coupled thermal stress analysis approach is presented for modelling temperature and distortion profiles resulting from welding thin-walled structures. The material is modelled as thermo-elastic–plastic with isotropic strain hardening. The heat source is modelled as a three-dimensional (3-D) double ellipsoid, and 3-D finite element (FE) models are employed for predicting ensuing distortions. Comparisons between the simulation results and experiments performed for eight weld configurations are presented. The weld configurations include bead-on-plate, butt weld and tee joint welds with varying plate thicknesses. Temperature measurements using thermocouples and an infrared (IR) imaging radiometer are directly compared to the thermal simulations. Likewise, distortions measured directly on the experimental set-ups are compared to the FE distortion predictions. Very good correlation is obtained for temperature as well as distortion predictions between experimental and proposed numerical a...