The use of active flux in tungsten inert gas (TIG) welding is known to increase its weld depth. The present paper involves study of active flux laser beam welding (ALBW) of austenitic stainless steel sheets with respect to its effect on plasma plume, microstructure and mechanical properties of the resultant weldments. ALBW performed with SiO2 as the flux significantly modified shape of the fusion zone (FZ) to produce narrower and deeper welds. Plasma plume associated with the process was considerably smaller and of lower intensity than that produced during bead on plate laser beam welding (LBW). Flux addition during LBW produced thin and rough weld bead associated with humping. The development of such a weld bead is cause by reversal in the direction of Marangoni flow by oxygen induced inversion of surface tension gradient, widely fluctuating plasma plume and presence of oxides on the weld pool surface preventing free flow of the melt. Active flux laser weldments exhibited lower ductility than that of bead on plate laser weldments.
NaitoY., MizutaniM. and KatayamaS.: J. Laser Appl., 2006, 18, (1), 21–27.
14.
HeipleC. R., RoperJ. R., StagnerR. T. and AdenR. J.: Weld. J., 1983, 62, 72s–77s.
15.
DingF., RuihuaZ., NakataK., TanakaM. and UshioM.: China Weld., 2003, 12, (2), 83–86.
16.
CretteurL. and MaryaS.: Weld. Int. (UK), 2000, 14, (2), 120–134.
17.
SuY., AartsR. G. K. M. and MeijerJ.: Proc. Int. Cong. on ‘Application of lasers & electro-optics’, Dearborn, MI, USA, October 2000, Laser Institute of America, C35–C41.
18.
BeckM., BergerP. and HugelH.: J. Phys. D, 1995, 28D, 2430–2442.
19.
DuleyW. W.: ‘Laser welding’, 33–35; 1999, New York, John Wiley & Sons.
VitolE. N. and OrlavaK. B.: Izv. Akad. Nauk SSSR Metall., 1984, (4), 37–42.
22.
FuhrichT., BergerP. and HugetH.: Proc. Int. Cong. on ‘Application of lasers & electro-optics’, San Diego, CA, USA, November 1999, Laser Institue of America, E166–176.
PangW., ManH. C. and YueT. M.: Mater. Sci. Eng. A, 2005, 390A, (1–2), 144–153.
25.
Available at: http://www.chemicalland21.com/industrialchem/solalc/POLYVINYL%20ALCOHOL.htm, 25, accessed date August 17, 2006.
26.
Available at: http://www.dcchem.co.kr/english/product/p_petr/p_petr8.htm, accessed date August 2, 2006.
27.
VoraH. S., NakheS. V., SarangpaniK. K., SaxenaP., ShirkeN. D. and BhatnagarR.: ‘Promise – a software for profile measurement of image size and edge enhancement’, Report CAT/95-10-1996, Centre for Advanced Technology, Indore, India, 1996.
28.
VoraH. S., SaxenaP., SinghN., ShuklaP. K. and ShenoyN. M.: Proc. National Laser Symp., Mumbai, India, January 2005, BRNS & DAE, 759–760.
29.
‘Boiler and pressure vessel code’, Section IX, ‘Welding & brazing qualification’, 4, 120, ASME, New York, USA, 1986.
30.
‘Standard method for guided bend test for ductility of welds’, ASTM 1986, 190–80, 359–362.
31.
GriemH. R.: ‘Plasma spectroscopy’; 1964, New York, McGraw Hill.
32.
MatsunawaA., KimJ. D., TakemotoT. and KatayamaS.: Proc. Int. Cong. on ‘Application of lasers & electro-optics’, San Diego, CA, USA, November 1995, Laser Institue of America, 719–728.
33.
MuellerR. E.: Proc. Int. Cong. on ‘Application of lasers & electro-optics’, Detroit, MI, USA, October 1996, Laser Institue of America, B68–B75.
34.
LacroixD. and JeandelG.: J. Appl. Phys., 1997, 81, (10), 6599–6606.
35.
HoffmanJ. and SzymanskiZ.: J. Phys. D, 2004, 37D, 1792–1799.
36.
MillsK. C. and KeeneB. J.: Int. Mater. Rev., 1990, 35, 185–216.
37.
MillsK. C., KeeneB. J., BrooksR. F. and ShiraliA.: Philos. Trans. Royal Soc. Lond. A, 1998, 356A, 911–925.
38.
GratzkeU., KapadiaP. D., DowdenJ., KroosJ. and SimonG.: J. Phys. D, 1992, 25D, 1640–1647.
39.
BeersiekJ., DevermannT. and BehlerK.: Proc. Int. Cong. on ‘Applications of lasers and electo-optics’, San Francisco, CA, USA, October 2004, Laser Institute of America.
40.
HoneycombeR. W. K.: ‘The plastic deformation of metals’, 184–185; 1977, London, Edward Arnold.
41.
DavisJ. R. (ed.): ‘Metals handbook – desk edition’, 2nd edn, 1214; 1998, Materials Park, OH, ASM International.
