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.

Fuel cell operated welder

Abstract: An electric arc welder powered by a plurality of liquid organic fuel cells The fuel cells use a methanol/water mixture as the organic feed The fuel cells produce carbon dioxide as a reactive product which is used an a shielding gas during the arc welding process The fuel cells are stacked together to produce the desired arc voltage and current between an electrode and the workpiece The arc welder includes a welding current to control the current wave shape through the electrode and to control or increase the voltage through the electrode

Microstructural Characteristics of a Stainless Steel/Copper Dissimilar Joint Made by Laser Welding

Abstract: The microstructures and its formation mechanism of a stainless steel/copper dissimilar joint by laser welding were investigated. It was found that the two modes of joining, i.e., welding-brazing and fusion welding, depend on different processing parameters. In the welding-brazing mode, the interface between copper and the fusion zone has scraggy morphology because the molten pool is frozen by solid copper with high thermal conductivity. The interdiffusion of elements occurs in the neighborhood of the interface, which leads to the metallurgy bond of the mode. In the fusion welding mode, the liquid phase in the fusion zone undergoes not only primary but also secondary liquid separation due to the high cooling rate and high supercooling level of laser welding. Some microcracks generated in the fusion zone by thermal stress mismatch are healed by liquid copper filling.

Control of Microstructures and Properties in Steel Arc Welds

Abstract: Control of Microstructures and Properties in Steel Arc Welds provides an overview of the most recent developments in welding metallurgy. Topics discussed include common welding processes, the thermal cycle during welding, defects that may occur during the welding process, the metallurgy of the material, metallurgical processes in the heat-affected zone and the fused metal, and the relationship between microstructures and mechanical properties. The book's final chapter presents examples of welded joints, illustrating how modern theories are capable of predicting the microstructure and properties of these joints. This book is an excellent resource for welding engineers, metallurgists, materials scientists, and others interested in the subject.

Predictions of microstructures when welding automotive advanced high-strength steels : A combination of thermal and microstructural modeling can be used to estimate performance of welds in advanced high-strength steels

Abstract: Weld strength, formability, and impact resistance for joints on automotive steels are dependent on the underlying microstructure. A martensitic weld area is often a precursor to reduced mechanical performance. In this paper, efforts are made to predict underlying joint microstructures for a range of processing approaches, steel types, and gauges. This was done first by calculating cooling rates for some typical automotive processes [resistance spot welding (RSW), resistance mash seam welding (RMSEW), laser beam welding (LBW), and gas metal arc welding (GMAW)]. Then, critical cooling rates for martensite formation were calculated for a range of automotive steels using available thermodynamically based phase transformation models. These were then used to define combinations of process type, steel type, and gauge where welds could be formed avoiding martensite in the weld area microstructure.