Issue 50

L. Romanin et al., Frattura ed Integrità Strutturale, 50 (2019) 251-263; DOI: 10.3221/IGF-ESIS.50.21 262 spherical heat source in the upper part of the sheets takes into account the wide fusion zone caused by the electron beam defocalization, while a conical heat source models the penetration depth of the electron beam. Thermal numerical results have been demonstrated to be in close agreement with the experiment in terms of both FZ shape and temperature histories at different points far from the weld line. A CKNOWLEDGEMENTS he authors gratefully acknowledge the experimental support provided by Zanon S.p.A., Schio (VI), Italy. R EFERENCES [1] Holcomb, D.F.A. (1989).-. Proceedings of the International Conference on Superalloys 718, 625, 706 and Derivatives, Superalloy 718—Metallurgy and Applications, The Minerals, Metals & Materials Society, Warrendale, PA, pp. 467– 478. [2] Li, Z., Gobbi, S.L., Bonollo, F., Tiziani, A., Fontana, G. (1998). Metallurgical investigation of laser welds in wrought Waspaloy, Sci. Technol. Weld. Join., 3(1), pp. 1–7. [3] Han, W.J., Byeon, J.G., Park, K.S. (2001). Welding characteristics of the Inconel plate using a pulsed Nd: YAG laser beam, J. Mater. Process. Technol., 113(1–3), pp. 234–237. [4] Li, Z., Gobbi, S.L., Loreau, J.H. (1997). Laser welding of Waspaloy®sheets for aero-engines, J. Mater. Process. Technol., 65(1–3), pp. 183–190. [5] David, S.S., Babu, J.M.V. (1998). Mathematical Modeling of Weld Phenomena 4, The Institute of Materials, London, pp. 269–289. [6] Beemer, L.J.M. (1962). Weld. J. Weld. Res. Suppl. 41, pp. 267s–273s. [7] Roberts, H.J. Stone, J.M. Robinson, P.J. Withers, R.C. Reed, D.R. Crooke, B.J. Glassey, D.J.H. (1998). Mathematical Modeling of Weld Phenomena 4, pp. 631–640. [8] Ferro, P., Bonollo, F., Tiziani, A. (2010). Methodologies and experimental validations of welding process numerical simulation, Int. J. Comput. Mater. Sci. Surf. Eng., 3(2–3), pp. 114–32. [9] Klykov, N.A., Dammer, A.A., Druzhinin, A. V., Malysh, M.M. (1987). Calculations of the form of the penetration zone in laser welding using a model of two heat sources, Weld. Int., 1(10), pp. 914–916. [10] Steen, W.M., Dowden, J., Davis, M., Kapadia, P. (1988). A point and line source model of laser keyhole welding, J. Phys. D. Appl. Phys., 21(8), pp. 1255. [11] Rosenthal, D. (1946). The theory of moving sources of heat and its application of metal treatments, Trans. ASME, 68, pp. 849–866. [12] Bonollo, F., Tiziani, A., Zamban, A. (1993). Model for CO 2 laser welding of stainless steel, titanium, and nickel: parametric study, Mater. Sci. Technol., 9(12), pp. 1137–1144. [13] Binda, B., Capello, E., Previtali, B. (2004). A semi-empirical model of the temperature field in the AISI 304 laser welding, J. Mater. Process. Technol., 155, pp. 1235–1241. [14] Tsirkas, S.A., Papanikos, P., Kermanidis, T. (2003). Numerical simulation of the laser welding process in butt-joint specimens, J. Mater. Process. Technol., 134(1), pp. 59–69. [15] Du, H., Hu, L., Liu, J., Hu, X. (2004). A study on the metal flow in full penetration laser beam welding for titanium alloy, Comput. Mater. Sci., 29(4), pp. 419–427. [16] Feng, Z., David, S.A., Zacharia, T., Tsai, C.L. (1997). Quantification of thermomechanical conditions for weld solidification cracking, Sci. Technol. Weld. Join., 2(1), pp. 11–19. [17] Dye, D., Hunziker, O., Reed, R.C. (2001). Numerical analysis of the weldability of superalloys, Acta Mater., 49(4), pp. 683–697. [18] Mayor, R.A. (1976). Weld. J. Weld. Res. Suppl. 55, pp. 269s–275s. [19] Ferro, P., Zambon, A., Bonollo, F. (2005). Investigation of electron-beam welding in wrought Inconel 706 — experimental and numerical analysis, 392, pp. 94–105, DOI: 10.1016/j.msea.2004.10.039. [20] Lacki, P., Adamus, K. (2011). Numerical simulation of the electron beam welding process, Comput. Struct., 89(11– 12), pp. 977–985, DOI: 10.1016/j.compstruc.2011.01.016. T