Abstract
The paper introduces the results of mixing and fluid flow
studies for full penetration laser-gas metal arc (GMA)
hybrid welding with GMA leading and trailing torch
configuration. The material used was austenitic stainless
steel with the thickness of 10 mm. The joint
configuration was butt joint without gap. It was found
that the molten pool at the root side is a longer time in
the molten state than the pool at the weld surface.
Compared to autogeneous laser welding, the addition of
GMA makes the upper bead wider. This effect is more
prominent in the case of GMA trailing compared to the
case of GMA leading. The simulation results also show a
similar trend of bead shape change in the case of GMA
leading and trailing configuration compared to the
experimental ones. Mixing behavior of filler and base
metal is also evaluated and compared by both experimental
studies and simulations. In GMA leading configuration,
the mixing is more pronounced in the upper part of the
weld cross section, while in GMA trailing, the mixing is
more efficient in the whole cross section compared to GMA
leading case. Simulation results support this difference
in mixing behavior. Laser is the main source that
provides full penetration and forms a molten pool on
upper and root surface. The direction of wire feeding
affects the mixing behavior. In GMA leading configuration
the wire droplets impinge in front of the laser beam and
in the front edge of the molten pool, whereas in GMA
trailing configuration, the wire droplets impinge behind
the laser beam where the molten pool is fully developed.
This causes the difference in mixing.
Original language | English |
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Article number | 042009 |
Journal | Journal of Laser Applications |
Volume | 29 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Nov 2017 |
MoE publication type | A1 Journal article-refereed |
Keywords
- laser-GMA hybrid welding
- element mixing
- GMA leading
- GMA trailing
- volume of fluid method
- full penetration
- keyhole
- fiber laser