Effect of Torch Angle on Arc Properties and Weld Pool Shape in Stationary GTAW
Publication: Journal of Engineering Mechanics
Volume 139, Issue 9
Abstract
In this paper, a three-dimensional (3D) numerical simulation is performed on a stationary arc to study the effect of torch angles in gas tungsten arc welding (GTAW) of SS304 stainless steel. A comparison has been made to investigate 90 and 70° torch angles and analyze the effect on arc and weld pool shape. Current density, heat flux, and gas shear stress are calculated in the arc region and are used as input to the workpiece to determine the weld pool. Also, both buoyancy and Marangoni shear affect the weld pool shape and are taken into account. The computed and experimental results are observed as symmetric for the 90° torch angle. For the 70° torch angle, current density and hence the heat flux from electron contribution is found to be the maximum behind the electrode tip in the welding direction. Heat flux from conduction and convection is found to be the maximum ahead of the electrode tip in the welding direction. This makes the maximum of total heat flux symmetric along the arc center. Heat flux from conduction and convection decreases as the torch angle decreases resulting in a shallow weld pool. The nonsymmetric -shaped weld pool is developed by the combined effect of the gas shear and Marangoni convection. It is found that for the 70° torch angle, the weld pool becomes nonsymmetric, shallow, and wide ahead of the electrode tip in the welding direction. The numerical weld pool shapes are verified through experiments.
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References
ANSYS. (2010). ANSYS CFX- solver theory guide, ANSYS, Inc., Canonsburg, PA.
Choo, R. T. C., Szekely, J., and David, S. A. (1992). “On the calculation of the free surface temperature of gas-tungsten-arc weld pools from first principles: Part II. Modeling the weld pool and comparison with experiments.” Metall. Trans. B, 23(3), 371–384.
Du, H. Y., Wei, Y. H., Wang, W. X., Lin, W. M., and Fan, D. (2009). “Numerical simulation of temperature and fluid in GTAW arc under changing process conditions.” J. Mater. Process. Technol., 209(8), 3752–3765.
Ferjutz, K., and Davis, J. R. (1993). “ASM handbook: Vol. 6: Welding, brazing, and soldering.” ASM Int., Materials Park, OH.
Gleizes, A., Bouaziz, M., Gonzalez, J. J., and Razafinimanana, M. (1997). “Influence of the anode material on an argon arc.” IEEE Trans. Plasma Sci., 25(5), 891–896.
Gleizes, A., Gonzalez, L. L., and Freton, P. (2005). “Thermal plasma modeling.” J. Phys. D Appl. Phys., 38, R153–R183.
Gonzalez, J. J., Lago, F., Freton, P., Masquere, M., and Franceries, X. (2005). “Numerical modeling of an electric arc and its interaction with the anode: Part II. The three-dimensional model-influence of external forces on the arc column.” J. Phys. D Appl. Phys., 38(2), 306–318.
Goodarzi, M., Choo, R., Takasu, T., and Toguri, J. M. (1998). “The effect of the cathode tip angle on the gas tungsten arc welding arc and weld pool: II. The mathematical model for the weld pool.” J. Phys. D Appl. Phys., 31(5), 569–583.
Haidar, J., and Farmer, A. J. D. (1994). “Large effect of cathode shape on plasma temperature in high-current free-burning arcs.” J. Phys. D Appl. Phys., 27(3), 555–560.
Kanouff, M., and Greif, R. (1992). “The unsteady development of a GTA weld pool.” Int. J. Heat Mass Transfer, 35, 967–979.
Kim, W. H., and Na, S. J. (1998). “Heat and fluid flow in pulsed current GTA weld pool.” Int. J. Heat Mass Transfer, 41(21), 3213–3227.
Leibowitz, L. (1976). “Properties for LMFBR safety analysis.” Rep. No. ANL-CEN-RSD-76-1, Argonne National Laboratories, Argonne, IL.
Li, Z. Y., and Wu, C. S. (1997). “Analysis of the transport phenomena in the interfacial region between TIG arcs and weld pools.” Comput. Mater. Sci., 8(3), 243–250.
Lowke, J. J., Morrow, R., and Haidar, J. (1997). “A simplified unified theory of arcs and their electrodes.” J. Phys. D Appl. Phys., 30(14), 2033–2042.
Lu, F., Tang, X., Yu, H., and Yao, S. (2006). “Numerical simulation on interaction between TIG welding arc and weld pool.” Comput. Mater. Sci., 35(4), 458–465.
Lu, F., Yau, S., Lou, S., and Li, Y. (2004). “Modeling and finite element analysis on GTAW arc and weld pool.” Comput. Mater. Sci., 29, 371–378.
Miller Electric Manufacturing. (2008). Guidelines for gas tungsten arc welding (GTAW), Illinois Tool Works, Co., Appleton, WI.
Murphy, A. B., and Arundell, C. J. (1994). “Transport coefficients of argon, nitrogen, oxygen, argon-nitrogen, and argon-oxygen plasmas.” Plasma Chem. Plasma Process., 14(4), 451–490.
Quigley, M. B. C., Richards, P. H., Swift-Hook, D. T., and Gick, A. E. F. (1973). “Heat flow to the workpiece from a TIG welding arc.” J. Phys. D Appl. Phys., 6, 2250–2258.
Sansonnens, L., Haidar, J., and Lowke, J. J. (2000). “Prediction of properties of free burning arcs including effects of ambipolar diffusion.” J. Appl. Phys., 33(2), 148–157.
Shinichi, T., Manbu, T., and Masao, U. (2005). “Numerical simulation of GTAW in different gaseous atmospheres.” Trans. JWRI, 34(2), 1–5.
Speckhofer, G., and Schmidt, H.-P. (1996). “Experimental and theoretical investigation of high-pressure arcs-Part II: The magnetically deflected arc (three-dimensional modeling).” IEEE Trans. Plasma Sci., 24(4), 1239–1248.
Tanaka, M., Terasaki, H., Ushio, M., and Lowke, J. J. (2002). “A unified numerical modeling of stationary tungsten inert gas welding process.” Metall. Mater. Trans. A, 33, 2043–2052.
Thompson, M. E., and Szekely, J. (1989). “The transient behavior of weldpools with a deformed free surface.” Int. J. Heat Mass Transfer, 32(6), 1007–1019.
Westhoff, R. C. (1989). “A mathematical model for current, heat flux and pressure in a welding arc.” Ph.D. thesis, Dept. of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA.
Wu, C. S., and Gao, J. Q. (2002). “Analysis of the heat flux distribution at the anode of a TIG welding arc.” Comput. Mater. Sci., 24(3), 323–327.
Xu, Y. L., Dong, Z. B., Wei, Y. H., and Yang, C. L. (2007). “Marangoni convection and weld shape variation in A-TIG welding process.” Theor. Appl. Fract. Mech., 48(2), 178–186.
Zhu, P., Lowke, J. J., Morrow, R., and Haidar, J. (1995). “Prediction of anode temperatures of free burning arcs.” J. Appl. Phys., 28(7), 1369–1376.
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© 2013 American Society of Civil Engineers.
History
Received: May 20, 2011
Accepted: Sep 21, 2012
Published online: Sep 23, 2012
Published in print: Sep 1, 2013
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