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.

Numerical Analysis of Metal Transfer in Gas Metal Arc Welding under Modified Pulsed Current Conditions

Abstract: A method has been proposed to pulsate current in gas metal arc welding (GMAW) to achieve a specific type of desirable and repeatable metal transfer mode, i.e., one drop per pulse (ODPP) mode. This method uses a peak current lower than the transition current to prevent accidental detachment and takes advantage of the downward momentum of the droplet oscillation to enhance the detachment. A numerical model with advanced computational fluid dynamics (CFD) techniques, such as a two-step projection method, volume of fluid (VOF) method, and continuum surface force (CSF) model, was used to carry out the simulation for the metal transfer process. The Gauss-type current density distribution was assumed as the boundary condition for the calculation of the electromagnetic force. The calculations were conducted to demonstrate the effectiveness of the proposed method in achieving the desired metal transfer process in comparison with conventional pulsed current GMAW. Also, the critical conditions for effective use of this proposed method were identified by the numerical simulation. Comparison showed good agreement between calculation and experimental results.

Numerical analysis of metal transfer in gas metal arc welding

Abstract: The present article describes a numerical procedure to simulate metal transfer and the model will be used to analyze the transport processes involved in gas metal arc welding (GMAW). Advanced Computational fluid dynamics (CFD) techniques used in this model include a two-step projection method for solving the incompressible fluid flow; a volume of fluid (VOF) method for capturing free surface; and a continuum surface force (CSF) model for calculating surface tension. The electromagnetic force due to the welding current is estimated by assuming several different types of current density distribution on the free surface of the drop. The simulations based on the assumption of Gaussian current density distribution show that the transition from globular to spray transfer mode occurs over a narrow current range and the size of detached drops is nonuniform in this transition zone. The analysis of the calculation results gives a better understanding of this physical procedure. Comparisons between calculated results and experimental results are presented. It is found that the results computed from the Gaussian assumption agree well with those observed in experiments.

Welding method combining laser welding and MIG welding

Abstract: Welding of deep penetration is obtained in a sustrate by a method which comprises first melting the joint portion of the substrates by MIG welding and then focusing a laser beam in the bottom surface of a crater formed in consequence of the MIG welding thereby effecting laser welding of the crater.