href="#ulink_445977cb-0141-5bf2-9bbb-d46879752db2">Figure E1.2, the tip of the filler metal wire is dipped in the weld pool and the wire itself is resistance heated by means of a second power source between the contact tube of the wire and the workpiece. In the case of steels, the deposition rate can be more than doubled this way. (a) Is an AC or DC power source preferred for heating the wire, and if so, why? (b) Can this process be expected to be as effective for aluminum and copper alloys? (c) Why is this process better than conventional GTAW for depositing a corrosion‐ or wear‐resistant overlay on steel?
Figure E1.2 Hot wire GTAW process.
Answer
1 (a) An AC power source is preferred for heating the wire in order to avoid arc blow. With DC an electromagnetic force can be induced around the hot wire to deflect a DC welding arc, especially when the current is high.
2 (b) No, this process is not expected to be as effective for welding Al and Cu alloys because the low electrical resistance of these filler wires means ineffective resistance heating.
3 (c) High deposition rates can be obtained without using high arc powers, which can melt too much base metal to excessively dilute the deposit.
References
1 1 Kearns, W.H. (ed.) (1980). Welding Handbook, 7e, vol. 3, 170–238. Miami, FL: American Welding Society.
2 2 Mendez, P.F. and Eagar, T.W. (2001). Welding processes for aeronautics. Advanced Materials and Processes 159 (5): 39–43.
3 3 American Welding Society (1976). Welding Handbook, 7e, vol. 1, 2–32. Miami, FL: American Welding Society.
4 4 (1998). Welding workbook, data sheet 212a. Welding Journal 77: 65.
5 5 American Welding Society (1978). Welding Handbook, 7e, vol. 2, 78–112, 296–330. Miami, FL: American Welding Society.
6 6 Lyttle, K. (1993). Shielding gases. In: Welding, Brazing and Soldering, ASM Handbook, vol. 6, 64–69. Materials Park, OH: ASM International.
7 7 Schwartz, M.M. (1979). Metals Joining Manual, 2–1 to 3–40. New York: McGraw‐Hill.
8 8 Lesnewich, A. (1978). The welding processes in relation to weldability. In: Weldability of Steels, 3e (eds. R.D. Stout and W.D. Doty), 5. New York, NY: Welding Research Council.
9 9 Gibbs, F.E. (1980). Ceramic backing for all‐position GMA welding 5083 aluminum‐alloy. Welding Journal 59 (12): 23s–30s.
10 10 (2000). Fact sheet—choosing shielding for GMA welding. Welding Journal 79: 18.
11 11 Jones, L.A., Eagar, T.W., and Lang, J.H. (1998). Images of a steel electrode in Ar‐2% O~ 2 shielding during constant current gas metal arc welding. Welding Journal 77 (4): 135s–141s.
12 12 Blackman, S.A. and Dorling, D.V. (2000). Technology advancements push pipeline welding productivity. Welding Journal 79 (8): 39s–44s.
13 13 Eichhorn, F., Remmel, J., and Wubbels, B. (1984). High‐speed electroslag welding. Welding Journal 63 (1): 37s–41s.
14 14 Cary, H.B. (1979). Modern Welding Technology. Englewood Cliffs, NJ: Prentice‐Hall.
15 15 Arata, Y., Development of ultra high energy density heat source and its application to heat processing, Okada Memorial Japan Society, New York, NY. 1985.
16 16 Farrell, W.J. (1962‐1963). ASTME Paper SP 63–208. The Use of Electron Beam to Fabricate Structural Members. Creative Manufacturing Seminars.
17 17 Blakeley, P.J. and Sanderson, A. (1984). The origin and effects of magnetic fields in electron beam welding. Welding Journal 63 (1): 42s–49s.
18 18 Metzbower, E.A., Private communication. Naval Research Laboratory: Washington, DC.
19 19 Bliedtner, J., Heyse, T., Jahn, D. et al. (2001). Advances in diode lasers increase weld penetration. Welding Journal 80 (6): 47s–51s.
20 20 Quintino, L., Costa, A., Miranda, R. et al. (2007). Welding with high power fiber lasers–a preliminary study. Materials & Design 28 (4): 1231–1237.
21 21 Xie, J. and Kar, A. (1999). Laser welding of thin sheet steel with surface oxidation. Welding Journal 78: 343s–348s.
22 22 Mazumder, J. Procedure development and practice considerations for laser‐beam welding. In: Welding, Brazing and Soldering, ASM Handbook, vol. 6, 874. Materials Park, OH: ASM International.
23 23 Rockstroh, T.J. and Mazumder, J. (1987). Spectroscopic studies of plasma during cw laser materials interaction. Journal of Applied Physics 61 (3): 917–923.
24 24 Seaman, F. Technical Paper MR77‐982, Role of Shielding Gas in Laser Welding. 1977, Society of Manufacturing Engineers: Dearborn, MI.
25 25 Hyatt, C.V., Magee, K.H., Porter, J.F. et al. (2001). Laser‐assisted gas metal arc welding of 25‐mm‐thick HY‐80 plate. Welding Journal 80 (7): 163s–172s.
26 26 Albright, C.E., Eastman, J., and Lempert, W. (2001). Low‐power lasers: assist arc welding. Welding Journal 80 (4): 55s–58s.
27 27 (1980). Welding Handbook, 7e, vol. 3, 44. Miami, Florida: American Welding Society.
28 28 Thomas, W.M. (1991). Friction stir butt welding. International Patent Application No. PCT/GB92, Patent Application No. 9125978.8, filed December 6, 1991.
29 29 Bhamji, I. et al. (2011). Solid state joining of metals by linear friction welding: a literature review. Materials Science and Technology 27 (1): 2–12.
30 30 Ushio, M., Matsuda, F., and Sadek, A.A. (1993). GTA welding electrode. In: International Trends in Welding Science and Technology (eds. S.A. David and J.M. Vitek), 405–409. ASM International, Materials Park, OH.
Further Reading
1 Arata, Y. (1985). Development of Ultra High Energy Density Heat Source and its Application to Heat Processing. Osaka, Japan: Okada Memorial Japan Society, New York, NY for the Promotion of Welding.
2 DebRoy, T., De, A., Bhadeshia, H.K.D.H. et al. (2012). Tool durability maps for friction stir welding of an aluminium alloy. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468 (2147): 3552–3570.
3 Duley, W.W. (1999). Laser Welding. New York: Wiley.
4 Olson, D.L., Siewert, T.A., Liu, S., and Edwards, G.R. (1993). ASM Handbook: Welding, Brazing, and Soldering, vol. 6. Materials Park, OH: ASM International.
5 Schwartz, M.M. (1979). Metals Joining Manual. New York: McGraw‐Hill.
6 (1980). Welding Handbook, Vols. 1–3, 7e. Miami, FL: American Welding Society.
Problems
1 11.1
