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2017 №08 (08) DOI of Article
10.15407/tpwj2017.08.01
2017 №08 (02)

The Paton Welding Journal 2017 #08
TPWJ, 2017, #8, 2-11 pages
 
Effective values of electrodynamic characteristics of the process of nonconsumable electrode welding with pulse modulation of arc current


Journal                    The Paton Welding Journal
Publisher                 International Association «Welding»
ISSN                      0957-798X (print)
Issue                       #4, 2017 (August)
Pages                      2-11
 
 
Authors
V.F. Demchenko, U. Boi, I.V. Krivtsun and I.V. Shuba
E.O. Paton Electric Welding Institute, NASU 11 Kazimir Malevich Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
 
Abstract
The paper is devoted to analysis of the influence of pulse modulation of welding current on effective values of electrodynamic characteristics of the process of nonconsumable electrode welding. The first part of the paper provides analysis of the possibilities for increasing the effective value of arc current through selection of optimum time and current parameters of pulse modulation. A quite general case of current modulation by pulses of trapezoidal shape is considered (rectangular and triangular pulses are treated as particular cases). In the second part distribution of effective values of electromagnetic and dynamic characteristics of modulated current in the weld pool is studied, proceeding from a nonstationary model of arc discharge and model of electromagnetic processes in the metal being welded. Force impact of modulated current on weld pool metal at current modulation by triangular pulses with pauses at 10 kHz frequency is considered as a characteristic example. Influence of dynamic effects in the pulsed arc on distribution of effective values of electromagnetic characteristics, namely centripetal component of Lorenz force and magnetic pressure, is analyzed. A conclusion is made that with optimum shape of current pulses dynamic effects arising in nonstationary arc are capable of essentially enhancing its force impact on weld pool metal in nonconsumable electrode welding with high-frequency current modulation, compared to welding by constant current coinciding in magnitude with effective value of modulated current. 19 Ref., 13 Figures.
 
Keywords: nonconsumable electrode welding, pulse current modulation, electrodynamic characteristics, effective value, weld pool metal, mathematical models
 
 
Received:                03.07.17
Published:               01.08.17
 
 
References
  1. Leitner, R.E., McElhinney, G.H., Pruitt, E.L. (1973) An investigation of pulsed GTA welding variables. Welding J., Res. Suppl., 9, 405–410.
  2. Omar, A.A., Lundin, C.D. (1979) Pulsed plasma-pulsed GTA arcs: A study of the process variables. Ibid., 4, 97–105.
  3. Cook, G.T., H.E.E.H. EASSA (1985) The effect of high-frequency pulsing of a welding arc. IEEE Transact. Ind. Appl., 1A-21, 5, 1294–1299.
  4. Kolasa, A., Matsunawa, A., Arata, Y. (1986) Dynamic characteristics of variable frequency pulsed TIG arc. of JWRI, 15(2), 173–177.
  5. Saedi, H.R.,Unkel, W. (1988) Arc and weld pool behavior for pulsed current GTAW. Welding J., Res. Suppl., 11, 247–255.
  6. Kim, W.H., Na, S.J. (1998) Heat and fluid flow in pulsed current GTA weld pool. J. Heat and Mass Transfer, 41(21), 3213–3227. https://doi.org/10.1016/S0017-9310(98)00052-0
  7. Wu, C.S., Zheng, W., Wu, L. (1999) Modelling the transient behaviour of pulsed current tungsten-inert-gas weld pools. Modelling Simul. Mater. Sci. Eng., 7(1), 15–23. https://doi.org/10.1088/0965-0393/7/1/002
  8. Onuki, J., Anazawa, Y., Nihei, M. et al. (2002) Development of a new high-frequency, high-peak current power source for high constricted arc formation. J. Appl. Phys., 41, 5821–5826. https://doi.org/10.1143/JJAP.41.5821
  9. Traidia, A., Roger, F., Guyot, E. (2010) Optimal parameters for pulsed gas tungsten arc welding in partially and fully penetrated weld pools. J. Therm. Sci., 49, 1197–1208. https://doi.org/10.1016/j.ijthermalsci.2010.01.021
  10. Traidia, A., Roger, F. (2011) Numerical and experimental study of arc and weld pool behaviour for pulsed current GTA welding. J. Heat and Mass Transfer, 54, 2163–2179. https://doi.org/10.1016/j.ijheatmasstransfer.2010.12.005
  11. Qi, B.J., Yang, M.X., Cong, B.Q. et al. (2013) The effect of arc behavior on weld geometry by high-frequency pulse GTAW process with 0Cr18Ni9Ti stainless steel. J. Adv. Manuf. Technol., 66, 1545–1553. https://doi.org/10.1007/s00170-012-4438-z
  12. Yang, M., Yang, Z., Cong, B. et al. (2014) A study on the surface depression of the molten pool with pulsed welding. Welding J., Res. Suppl., 93(8), 312–319.
  13. Sydorets, V.N., Krivtsun, I.V., Demchenko, V.F. et al. (2016) Calculation and experimental research of static and dynamic volt-ampere characteristics of argon arc with refractory cathode. The Paton Welding J., 2, 2–8. https://doi.org/10.15407/tpwj2016.02.01
  14. Demchenko, V.F., Krivtsun, I.V., Krikent, I.V. et al. (2017) Force interaction of arc current with self-magnetic field. Ibid., 3, 15–24. https://doi.org/10.15407/tpwj2017.03.03
  15. Landau, L.D., Lifshits, E.M. (1982) Electrodynamics of continuums. Vol. 8. Teoreticheskaya Fizika, Moscow: Nauka.
  16. Krivtsun, I.V., Demchenko, V.F., Krikent, I.V. (2010) Model of the processes of heat, mass and charge transfer in the anode region and column of the welding arc with refractory cathode. The Paton Welding J., 6, 2–9.
  17. Krivtsun, I.V., Krikent, I.V., Demchenko, V.F. (2013) Modelling of dynamic characteristics of a pulsed arc with refractory cathode. Ibid., 7, 13–23.
  18. Krivtsun, I.V., Krikent, I.V., Demchenko, V.F. (2015) Interaction of CO2-laser radiation beam with electric arc plasma in hybrid (laser + TIG) welding. Ibid., 3/4, 6–15.
  19. Sokolov, O.I., Gladkov, E.A. (1977) Dynamic characteristics of free and constricted alternating current welding arcs with non-consumable electrode. Proizvodstvo, 4, 3–5.

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