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Abstract
The relationship between surface tension of molten 304L stainless steel and the welding bed geometry is studied. Welding experiments by Gas Metal Arc Welding (GMAW) in spray arc transfer were performed under different gas mixture composed of argon and oxygen in order to modify the surface tension and the Marangoni convection. The influence of oxygen in the shielding gas was studied by measuring geometric welds characteristics (width, depth and height) and droplet characteristics (frequency, velocity and diameter). It is shown that oxygen has a small influence on welding shape. In addition, a COMSOL Multiphysics® hydrodynamic model were performed in order to understand key phenomena responsible of the welding bed geometry. Also, welding bed oxygen measurements were carried out by Instrumental Gas Analysis to study the oxygen absorption in our welds. The oxygen content grows up with increasing oxygen content in the gas. Multiple layer deposit by WAAM with different gas mixture composed of Ar and O were used to study the variation of mechanical properties. It's demonstrated that oxygen as an impact on strength properties of 304L deposit.
Keywords: Surface tension, Marangoni, welding, WAAM, stainless steel.
| Speaker Country | France |
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