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.

Arc welding process and apparatus

Abstract: 930,436. Coating with metals; weld coating. UNION CARBIDE CORPORATION. Nov. 8, 1961 [Nov. 15, 1960], No. 39952/61. Class 82. A process and apparatus for weld-coating a workpiece 28 with an electric-arc torch in which an inert or reducing gas is discharged through nozzle 19 concentrically surrounding the end portion of non-consumable electrically insulated stick electrode 14 forming an arc between the end of the electrode and said nozzle, said arc together with said gas stream passing through orifice 12, thereby forming a highly heated wall-stabilized arc effluent, and feeding gasborne metallic coating powder 35 from conical channel 50 in the form of a converging conical stream into said effluent downstream of the orifice outlet and directing the powder-carrying effluent against the surface of the workpiece; an arc is also energized between said workpiece 28 and said stick electrode 14. The gas-borne powder is directed into the effluent at an entrance angle of between 25-80 degrees and the gas velocity and the concentration of the powder in the arc effluent is correlated with the ratio of the current supplied to the respective arcs to control the weld dilution of the coating. The adjustable non-transferred arc between the electrode 14 and the nozzle 19 is supplied from adjustable welding power source 16 and controls the heat to the effluent and the metallic powder; the independently adjustable transferred arc between the electrode 14 and workpiece 28 is supplied from adjustable source 26 and supplements the heat to the powder and controls the heat to the workpiece, thereby controlling weld dilution. Suitable inert or reducing gases are said to be A, He, H 2 , N 2 , Co or mixtures thereof depending on whether an inert, reducing or very high temperature effluent is required.

Numerical analysis of the heat source characteristics of a two-electrode TIG arc

Abstract: Various kinds of multi-electrode welding processes are used to ensure high productivity in industrial fields such as shipbuilding, automotive manufacturing and pipe fabrication. However, it is difficult to obtain the optimum welding conditions for a specific product, because there are many operating parameters, and because welding phenomena are very complicated. In the present research, the heat source characteristics of a two-electrode TIG arc were numerically investigated using a 3D arc plasma model with a focus on the distance between the two electrodes. The arc plasma shape changed significantly, depending on the electrode spacing. The heat source characteristics, such as the heat input density and the arc pressure distribution, changed significantly when the electrode separation was varied. The maximum arc pressure of the two-electrode TIG arc was much lower than that of a single-electrode TIG. However, the total heat input of the two-electrode TIG arc was nearly constant and was independent of the electrode spacing. These heat source characteristics of the two-electrode TIG arc are useful for controlling the heat input distribution at a low arc pressure. Therefore, these results indicate the possibility of a heat source based on a two-electrode TIG arc that is capable of high heat input at low pressures.

Joint tracking with a self-teaching system

Abstract: One stage of manufacturing shipping containers includes welding long corrugated iron sheets to stringers. Before welding, the corrugated iron sheet is aligned with the stringer and the joint is defined as an intersection of two surfaces. Until recently, this weldment was performed manually. Automating this operation presents a number of difficulties and is beneficial only if the cost of the final product is lower than what it was when done manually. The preparation of weldment components, their positions on the fixture and the distortion during welding require an adaptive control system for joint tracking. A self-teaching system, where the robot is entirely guided by information provided by sensors, without any previous learning of a reference trajectory, is essential in this case. The aim of this study is to prove that it is possible to perform tracking on a plane through a self-teaching system. The paper presents the method of joint location, the operating principle of the sensor and its mechanical and metrological properties.