Numerical Investigation of Transient Marangoni Effects on Weld Pool Dynamics in Gas Tungsten Arc Welding of Stainless Steel

2011 ◽  
Author(s):  
Debamoy Sen ◽  
Kenneth S. Ball ◽  
Mark A. Pierson
Keyword(s):  
Surface Tension ◽  
Stainless Steel ◽  
Weld Pool ◽  
Marangoni Convection ◽  
Driving Forces ◽  
Gta Welding ◽  
Flow Reversal ◽  
Surface Tension Gradient ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

In this study, the fluid flow, heat transfer, and phase change occurring during the Gas Tungsten Arc (GTA) welding of stainless steel are numerically analyzed. Of all the driving forces involved during GTA welding, the Marangoni convection due to surface tension gradient is the most dominant. The amount of surfactant present in the metal strongly influences the strength, location, and direction of the Marangoni convection. Limited work has been done in the study of transient Marangoni convection behavior in the regime where a significant amount of surfactant is present, and depending on the thermal distribution in the molten metal pool, the surface tension gradient undergoes inflection, resulting in a flow reversal. The present investigation aims to address the complex relationship among the flow reversal, surfactant activity, and thermal pattern in the weld pool.

A Study on Heat and Mass flow in Stationary Gas Tungsten arc Welding using the Numerical Mapping Method

1989 ◽  
Vol 203 (4) ◽  
pp. 233-242 ◽  
Author(s):  
S D Kim ◽  
S J Na
Keyword(s):  
Weld Pool ◽  
Moving Boundary ◽  
Driving Forces ◽  
Aerodynamic Drag ◽  
Surface Tension Force ◽  
Gta Welding ◽  
Mapping Method ◽  
Solid Boundary ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

The phase changing problem at the liquid-solid interface that occurs during stationary gas tungsten arc (GTA) welding has been studied by considering the four driving forces for weld pool convection, that is the electromagnetic force, the buoyancy force, the aerodynamic drag force and the surface tension force at the weld pool surface. In the numerical simulation, difficulties associated with the irregular shape of the moving interface have been successfully overcome by adopting a boundary-fitted coordinate system that eliminates the analytical complexity at the liquid-solid boundary. This method also has the capacity to handle the time-dependent changing solution domain of the moving boundary problem and could be applied effectively to this transient weld pool development problem with the moving boundary and phase change condition.

Heat Transfer Modelling and Investigation of the Effect of Pulse Frequency and Current in Pulsed Current Gas Tungsten Arc Welding

2014 ◽  
Vol 592-594 ◽  
pp. 395-399
Author(s):  
A. Prabakaran ◽  
R. Sellamuthu ◽  
Sanjivi Arul
Keyword(s):  
Heat Transfer ◽  
Weld Pool ◽  
Arc Welding ◽  
Gta Welding ◽  
Gas Tungsten Arc Welding ◽  
Transfer Model ◽  
Pulsed Current ◽  
Current Frequency ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Gas Tungsten Arc Welding (GTAW) involves several process parameters. In Pulsed Current GTAW frequency of pulse and pulse to time ratio differentiates the characteristics of weld pool geometry of from GTAW. In the present work a simple heat transfer model for Pulsed Current GTA welding was developed and the weld pool dimensions were experimentally verified with AISI 1020 steel. Relationship between speed and pulsed current frequency on weld pool dimension was studied. Weld pool dimension of pulsed and non-pulsed GTAW is studied.

scholarly journals Effect of Viscosity on the GTA Welds Bead Penetration in Relation with Surface Tension Elements

2016 ◽  
Vol 6 (2) ◽  
pp. 952-955
Author(s):  
K. Touileb ◽  
R. Djoudjou ◽  
A. Ouis
Keyword(s):  
Surface Tension ◽  
Stainless Steel ◽  
Viscous Dissipation ◽  
Molten Metal ◽  
Weld Pool ◽  
Marangoni Convection ◽  
Solid Compounds ◽  
Different Content ◽  
Bead Penetration

The aim of this paper is to study the effect of the viscous dissipation on the surface tension and its role on the shape of weld pool. Experiments were conducted on four different casts of ferritic stainless steel with different content in the sulfur and titanium. The results show in particular that the presence of titanium solid compounds affects the role of sulfur as surfactant element. Titanium in the presence of carbon and oxygen, titanium forms solid compounds which affect the Marangoni convection due to the sulfur element in the weld pool. The viscous dissipation due to these compounds alters the flow rate of the molten metal. We expect that the viscosity of metal liquid was altered by these solid compounds. The viscous dissipation due to these compounds contributes to heat the molten metal leading to larger weld bead.

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