Study On Simulation Analysis Of Welding Arc Under Different Atmosphere

Alternative a single gas with different gas mixtures as shielding atmosphere can combinethe advantages of welding under different atmosphere and improve their deficiencies. In thisarticle ANSYS software is used to numerical analyze of GTAW under different argon-ironvapour atmosphere and argon-helium mixture. ANSYS CFX is used to simulate the massdistribution of metal vapor in GMAW at the same time.A three-dimensional mathematical model of the welding arc under different atmosphereis developed on the basis of magnetic fluid dynamics and finite element theory. By makingbasic assumptions, giving the thermodynamic and transport parameters of the plasma underdifferent atmospheres, determining reasonable boundary conditions, it simulates the electricfield, the magnetic field and the flow field of the arc model by turns using ANSYSmulti-physics coupling function and makes the iterative loop calculations.The simulated result of the GTAW arc under different argon-iron vapour atmosphereshows that the addition of the iron vapour can significantly reduce the temperature of thewelding arc. With the increasing of iron vapour content in the mixed gases, the temperature ofthe welding arc under argon-iron vapour mixed atmosphere significantly reduced, and whenthe iron vapour content excesses50%, the arc characteristics of argon-iron vapour mixedatmosphere is similar to compression arc.The numerical simulation results of GTAW arc under argon-helium mixed atmosphereshows that the shape of the pure argon arc temperature was bell-shaped, while the shape of thepure helium arc temperature was spherical. The arc voltage and the average temperature of thearc under pure helium atmosphere was higher than that under pure argon atmosphere; Withthe increasing of helium content, the arc voltage under argon-helium mixed atmosphereincrease, and only when the content of helium gas is increased more than75%, the arc of themixed atmosphere presents the characteristic of helium. ANSYS CFX is used to simulate the mass distribution of metal vapor in GMAW, theresults show that the metal vapor content is the largest at the tip of the wire, and decreasesalong the axial direction.