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[email protected] 1 A Transient Unified Model of Arc Weld Pool Couplings during Spot GTA Welding COMSOL Conference, Boston 2010 A. TRAIDIA, and F. Roger ENSTA-Paristech & AREVA NP, FRANCE
A Transient Unified Model of Arc Weld Pool Couplings during Spot
GTA Welding
COMSOL Conference, Boston 2010
A. TRAIDIA, and F. Roger
ENSTA-Paristech & AREVA NP, FRANCE
Introduction
Gas Tungsten Arc Welding – Tungsten Inert Gas
A highly coupled multiphysics problem
Numerical modeling of pulsed GTA welding
State of art – Towards a unified formulation
Hsu et al (1982, …)
Gonzalez et al (1993, 1998, 2005, …)
Lowke, Tanaka et al
(1992, 1997, …, 2010)
Plasma
Plasma
+
Cooled copper anode
(No weld pool)
Cathode
+
Plasma
+
Stainless steel anode
(weld pool)
Numerical modeling of pulsed GTA welding
Toward a unified model Mathematical formulation
Inside the cathode, plasma, and anode
Plasma-cathode interface
Plasma-anode interface
Free surfaces of the weld pool
Main boundary conditions
4( ) ( ) i i e c Bcathode plasmak T n k T n jV j T
4( ) ( ) a Banode plasmak T n k T n j n T
( )a L
v s Tf
n T s
0
01
ln 11
exp
sg s s s
s
g
Ka HA R Ka
T Ka T
HK T k
R T
Numerical modeling of pulsed GTA welding
Application to pulsed current
welding 80/160 A
1 Hz
α 60°
Arc length 3 mm
Heating time: 15 s
304 L with 290 ppm sulfur
Pure argon
Tu
ng
ste
n
Imax
Imin
Time(s)
Welding current (A)
Numerical modeling of pulsed GTA welding
Results Application to pulsed current
welding
80/160 A- 1 Hz
α 60°- h 3 mm
Numerical modeling of GTA welding
80/160 A- 1 Hz
α 60°- h 3 mm Results Application to pulsed current
welding
Details about the weld pool evolution in: A. Traidia, F. Roger, E. Guyot. “Optimal parameters for pulsed gas
tungsten arc welding in partially and fully penetrated weld pools”. IJTS 2010.
Numerical modeling of pulsed GTA welding
80/160 A- 1 Hz
α 60°- h 3 mm
Fully penetrated weld pool
Solutions at t=4.5 s and t=5 s Free surfaces shape at different times
Results Application to pulsed current
welding
Experimental validation
Experimental procedure
Observation of the weld pool using an IR camera
Experimental validation
Validation
Experimenal width of the weld pool Matlab image processing algorithm
Experimental validation
Validation
Experiments/Calculations
Accumulation
of metal
vapors in the
arc plasma
Numerical modeling of GTA welding
Appendix A
Cathode (-)
Anode (+)
Plasma
Joule effect
Conduction to
the cathode
Thermoionic
emission
Ions absorption
Conduction to
the anode
Radiation
Joule effect
Air convection
Air convection
Radiation Conduction from
the plasma
Electrons
absorption
Radiation
Plasma physics
Numerical modeling of pulsed GTA welding
80/160 A- 1 Hz
α 60°- h 3 mm Appendix B Application to pulsed current
welding
Weld pool dimensions for a pulsed current welding and its constant mean current
