Modeling of Three-Dimensional Gas Metal Arc Welding With Groove

2007 ◽  
Author(s):  
J. Hu ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Plasma Arc ◽  
Droplet Impingement ◽  
Sulfur Species ◽  
Metal Arc Welding ◽  
Arc Pressure

This article analyzes the dynamic process of groove filling and the resulting weld pool fluid flow in gas metal arc welding of thick metals with V-groove. Filler droplets carrying mass, momentum, thermal energy, and sulfur species are periodically impinged onto the workpiece. The complex transport phenomena in the weld pool, caused by the combined effect of droplet impingement, gravity, electromagnetic force, surface tension, and plasma arc pressure, were investigated to determine the transient weld pool shape and distributions of velocity, temperature, and sulfur species in the weld pool. It was found that the groove provides a channel which can smooth the flow in the weld pool, leading to poor mixing between the filler metal and the base metal, as compared to the case without a groove.

scholarly journals Weld Pool Dynamics and the Formation of Ripples in 3D Gas Metal Arc Welding

2007 ◽  
Author(s):  
J. Hu ◽  
H. Guo ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Present Model ◽  
Gas Metal Arc Welding ◽  
Marangoni Effect ◽  
Surface Tension Force ◽  
Plasma Arc ◽  
Droplet Impingement ◽  
Metal Arc Welding ◽  
First Time

This article studies the transient weld pool dynamics under the periodical impingement of filler droplets that carry mass, momentum, thermal energy, and species in a moving 3D gas metal arc welding. The complicated transport phenomena in the weld pool are caused by the combined effect of droplet impingement, gravity, electromagnetic force, plasma arc force, and surface tension force (Marangoni effect). The weld pool shape and the distributions of temperature, velocity, and species in the weld pool are calculated as a function of time. The phenomena of “open and close-up” for a crater in the weld pool and the corresponding weld pool dynamics are analyzed. The commonly observed ripples at the surface of a solidified weld bead are, for the first time, predicted by the present model. Detailed mechanisms leading to the formation of ripples are discussed.

scholarly journals Investigation on the Dynamic Behavior of Weld Pool and Weld Microstructure during DP-GMAW for Austenitic Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 754
Author(s):  
Tao Chen ◽  
Songbai Xue ◽  
Peng Zhang ◽  
Bo Wang ◽  
Peizhuo Zhai ◽  
...  
Keyword(s):  
Weld Metal ◽  
Dynamic Behavior ◽  
Weld Pool ◽  
Heat Input ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Oscillation Amplitude ◽  
Droplet Impingement ◽  
Metal Arc Welding ◽  
Arc Pressure

The influence of heat and droplet transfer into weld pool dynamic behavior and weld metal microstructure in double-pulsed gas metal arc welding (DP-GMAW) was investigated by the self-designed high-speed welding photography system. The heat input, the arc pressure, the droplet momentum and impingement pressure were measured and calculated. It was found that the arc pressure is far less than the droplet impingement pressure. The heat input and droplet impingement pressure per unit time acting on weld pool were proportional to the current pulse frequency, which fluctuated with thermal pulse. The size and oscillation amplitude of the weld pool had noticeable periodic changes synchronized with the process of heat input and droplet impingement. Compared to the microstructure of pulsed gas metal arc welding (P-GMAW) weld metal, that of DP-GMAW weld metal was significantly refined. High oscillation amplitude assisted the enhancement of weld pool convection, which leads to more constitutional supercooling. The heat input and shear force during the peak of thermal pulse causing dendrite fragmentation which provided sufficient crystal nucleus for the growth of equiaxed grains and the possibility of grain refinement. The effects of current parameters on welding behavior and weld metal grain size are investigated for further understanding of DP-GMAW.

Modeling Heat and Mass Transfer and Fluid Flow in Three-Dimensional Gas Metal Arc Welding

Manufacturing ◽  
2002 ◽  
Author(s):  
Y. Wang ◽  
H. L. Tsai ◽  
S. P. Marin ◽  
P. C. Wang
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Marangoni Effect ◽  
Surface Tension Force ◽  
Droplet Impingement ◽  
Metal Arc Welding ◽  
Welding Direction ◽  
First Time

This paper extends a mathematical model and numerical techniques previously developed for simulating stationary 2-D gas metal arc welding (GMAW), to moving 3-D GMAW. The filler droplets carrying mass, momentum, thermal energy, and species periodically impinge onto the weld pool, while moving at a certain speed in the welding direction. The complicated transport phenomena in the weld pool are caused by the combined effect of droplet impingement, gravity, electromagnetic force, plasma arc force, and surface tension force (Marangoni effect). The weld pool shape and the distributions of temperature, species, and velocity in the weld pool are calculated as functions of time. For the first time, the phenomena of “open and close-up” for a crater and the formation of ripples at the surface of a solidified weld bead are predicted by mathematical modeling. Under the welding conditions used in the present study, detailed mechanisms leading to the formation of ripples are discussed.

Three-Dimensional Modeling of Gas Metal Arc Welding of Aluminum Alloys

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
H. Guo ◽  
J. Hu ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Welding Process ◽  
Weld Bead ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Metal Arc Welding ◽  
Arc Welding Process

A three-dimensional mathematical model and numerical techniques were developed for simulating a moving gas metal arc welding process. The model is used to calculate the transient distributions of temperature and velocity in the weld pool and the dynamic shape of the weld pool for aluminum alloy 6005-T4. Corresponding experiments were conducted and in good agreement with modeling predictions. The existence of a commonly observed cold-weld at the beginning of the weld, ripples at the surface of the weld bead, and crater at the end of the weld were all predicted. The measured microhardness around the weld bead was consistent with the predicted peak temperature and other metallurgical characterizations in the heat-affected zone.

scholarly journals Interactive Phenomena in Hybrid KPAW–GMAW-P

2020 ◽  
Vol 99 (05) ◽  
pp. 146s-155s
Author(s):  
DONGSHENG WU ◽  
◽  
SHINICHI TASHIRO ◽  
ZIANG WU ◽  
MANABU TANAKA ◽  
...  
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Video Camera ◽  
Plasma Arc ◽  
Tungsten Electrode ◽  
Current Path ◽  
Metal Arc Welding ◽  
High Speed Video Camera

A hybrid welding technique formed by combining keyhole plasma arc welding (KPAW) and pulsed gas metal arc welding (GMAW-P) is characterized by the complex interactions of the arc, droplet, keyhole, and weld pool. With the help of a high-speed video camera, zirconia particles, and a thermal camera, the complex interactive phenomena of the hybrid KPAW–GMAW-P process was analyzed. Owing to the formation of a direct-current path between the KPAW cathode (tungsten electrode) and the GMAW anode (welding wire), the ionized plasma arc was extended to the GMA side, causing an expansion of the GMA. The current at the GMAW droplet was diverged; thus, the Lorentz force promoted a more stable one pulse one droplet metal transfer mode compared with that of GMAW-P. The strong backward flow from the keyhole was suppressed because of the pull-push flow pattern on the top surface of the weld pool be-tween the two arcs. As the heat and molten metal in the weld pool were transported from the region near the GMA (high temperature) to the region near the plasma arc (low temperature), the weld pool temperature decreased.

Three-Dimensional Modeling of Plasma Arc in Arc Welding

2006 ◽  
Author(s):  
G. Xu ◽  
H. L. Tsai
Keyword(s):  
Magnetic Field ◽  
Weld Pool ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Plasma Arc ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling

Most previous three-dimensional modeling work in gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool. Almost all three-dimensional weld pool models are based on the two-dimensional axisymmetric Gaussian assumption of plasma arc pressure and heat flux. In this paper the three-dimensional plasma arc is modeled and results are presented. The velocity, pressure, temperature, current density, and magnetic field of the plasma arc are computed by solving the conservation equations of mass, momentum, and energy, as well as part of Maxwell's equations. This three-dimensional model allows one to study the non-axisymmetric plasma arc caused by external perturbations such as the external magnetic field. It also provides more accurate boundary conditions when modeling the welding pool. The future work is to unify it with the weld pool model and accomplish a complete three-dimensional model of GTAW and GMAW.

scholarly journals Numerical Analysis of Keyhole and Weld Pool Behaviors in Ultrasonic-Assisted Plasma Arc Welding Process

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 703
Author(s):  
Junnan Qiao ◽  
Chuansong Wu ◽  
Yongfeng Li
Keyword(s):  
Shear Stress ◽  
Weld Pool ◽  
Arc Welding ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Arc Pressure ◽  
Ultrasonic Assisted

The acoustic radiation force driving the plasma jet and the ultrasound reflection at the plasma arc-weld pool interface are considered to modify the formulas of gas shear stress and plasma arc pressure on the anode surface in ultrasonic-assisted plasma arc welding (U-PAW). A transient model taking into account the dynamic changes of heat flux, gas shear stress, and arc pressure on the keyhole wall is developed. The keyhole and weld pool behaviors are numerically simulated to predict the heat transfer and fluid flow in the weld pool and dynamic keyhole evolution process. The model is experimentally validated. The simulation results show that the acoustic radiation force increases the plasma arc velocity, and then increases both the plasma arc pressure and the gas shear stress on the keyhole wall, so that the keyholing capability is enhanced in U-PAW.

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