2) The typical droplet transfer mode during this underwater welding experiment was classified as repelled globular transfer with large droplets and low frequency. Under the given condition, the metal transfer frequency was obviously lower than the bubbles’ evolution frequency. This may have caused the extra forces on the droplets due to the unstable gas flow of the evolving bubbles. The big volume molten droplets were repelled by the complex forces, among which the cathode jet force and gas flow drag force may have contributed. 3) The arc cathode spot was captured drifting on the substrate intensively and continuously with very high frequency and speed. This behavior was negative for maintaining a stable welding process and made the forces on the droplets more complicated. The authors deduced that the oxide distribution and cold cathode substrate caused this phenomenon. Adding more oxides in the flux was considered a feasible method to reduce the arc drifting and deviation. 4) Under the impact of the water environment, the average electric potential gradient of the arc column was apparently much higher than other conventional GMAW methods. The special arc burning atmosphere, including hydrogen, oxygen, and vapor, caused the higher thermal conductivity and consequently higher electric potential gradient. The welding arc current density increased significantly due to the compression by the environment. 5) The asymmetric weld appearance and uneven surface with distortions were closely concerned with the complicated physical welding process. High-frequency evolving bubbles, lowfrequency droplet transfer, and drifting arc were the main factors influencing the welding process stability. The repelled large droplet transfer mode especially caused random transfer paths, uncertain landing locations, and intense fluctuation of the weld pool. And it was considered one of the most important factors causing the uneven weld appearance. The authors are grateful for the financial support for this research from the National Natural Science Foundation (No. 51105237) and Fundamental Research Funds of Shandong University (No. 2015TB002). 1. Perez-Guerrero, F., and Liu, S. 2005. Maintenance and repair welding in the open sea. Welding Journal 84(11): 54-s to 59-s. 2. Delaune, P. T., and Weber, J. D. 1979. Hyperbaric underwater welding: The state of the art — I. Welding Journal 58(8): 17-s to 25-s. 3. Liu, S., Olson, D. L., and Ibarra, S. 1993. Underwater welding. Welding, Brazing, and Soldering — ASM Handbook 6: 1010–1015. 4. Gao, H., Jiao, X. D., Xu, Y. G., X. U., and Zhou, C. F. 2014. Study of underwater friction welding technology. Welding Journal 93(9): 54-s to 58-s. 5. Rowe, M., and Liu, S. 2001. Recent developments in underwater wet welding. Science and Technology of Welding & Joining 6(6): 387 to 396. 6. Bucurel, R., and Hlifka, G. 2010. Laser beam welding process automates underwater repairs. Welding Journal 89(1): 47 to 49. 7. Lizunkova, Y., Hassel, T., Klotz, J., Wolyniec, A., and Bach, W. 2009. Development of filler wire for underwater welding as a repair tool for adaptation on AUV. OCEANS 2009-EUROPE, pp. 1–6. IEEE. 8. Paton, B. E. 1997. PWI activities in the field of underwater welding and cutting technologies. Underwater Wet Welding and Cutting, pp. 1–5. Woodhead Publishing. 9. Wu, C. S. 2008. Welding Thermal Processes and Weld Pool Behaviors. 141, Beijing, China Machine Press. 10. Pan, C. H., Du, S. M., Li, H., and Li, J. Y. 1997. Judgment local thermodynamic equilibrium of underwater plasma arc. Chinese Journal of Mechanical Engineering 33(5): 12 to 16, 48. 11. Wang, G. R., and Yang, Q. M. 1997. Spectroscopic study in temperature of underwater welding arc. Chinese Journal of Mechanical Engineering 33(2): 93 to 98. 12. Li, Z. G., Zhang, H., and Jia, J. P., 2009. Plasma component calculation in underwater wet welding. Transactions of China Welding Institute 30(4): 13 to 16. 13. Jia, C. B., Zhang, T., Maksimov, Y. S., and Yuan, X. 2013. Spectroscopic analysis on the arc plasma of underwater wet flux-cored arc welding. Journal of Materials Processing Technology 213(8): 1370 to 1377. 14. Tsai, C. L., and Masubuchi, K. 1979. Mechanisms of rapid cooling in underwater welding. Applied Ocean Research 1(2): 99 to 110. 15. Ghadimi, P., Ghassemi, H., Ghassabzadeh, M., and Kiaei, Z. 2013. Three-dimensional WELDING RESEARCH simulation of underwater welding and investigation of effective parameters. Welding Journal 92(8): 239-s to 249-s. 16. Zhang, H. T., Dai, X. Y., Feng, J. C., and Hu, L. L. 2015. Preliminary investigation on real-time induction heating-assisted underwater wet welding. Welding Journal 94(1): 8-s to 15-s. 17. Kim, Y. S., and Eagar, T. W. 1993. Analysis of metal transfer in gas metal arc welding. Welding Journal 72(1): 269-s to 274-s. 18. Shi, Y., Liu, X., Zhang, Y. M., and Johnson, M. 2008. Analysis of metal transfer and correlated influences in dual-bypass GMAW of aluminum. Welding Journal 87(9): 229-s to 236-s. 19. Madatov, N., Pokhodnya, I., and Kostenko, B. 1965. High speed x-ray cinematography of the underwater welding arc. Weld Prod 12(9): 72 to 73. 20. Guo, N., Du, Y. P., Feng, J. C., Guo, W., and Deng, Z. Q. 2015. Study of underwater wet welding stability using an x-ray transmission method. Journal of Materials Processing Technology 225: 133–138. 21. Fu, Y. L., Feng, J. C., Du, Y. P., Deng Z. Q., Wang, M. R., and Tang D. Y. 2016. Classification of metal transfer mode in underwater wet welding. Welding Journal 95(4): 133-s to 140-s. 22. Shi, Y. H., Wang, G. R., Zhong, J. G., Liu, S., and Liang, M. 2000. Edge detection of weld seam image during underwater flux-cored arc welding. Manufacturing Automation 22(11): 37 to 39. 23. Liu, S. 2000. Research on the welding area information of underwater fluxcored arc welding. PhD dissertation. Guangzhou, South China University of Technology. 24. Santos, V. R., Monteiro, M. J., Rizzo, F. C., Bracarense, A. Q., Pessoa, E. C. P., Marinho, R. R., and Vieira, L. A. 2012. Development of an oxyrutile electrode for wet welding. Welding Journal 91(12): 319-s to 328-s. 25. Guo, N., Guo, W., Du, Y. P., Fu, Y. L., and Feng, J. C. 2015. Effect of boric acid on metal transfer mode of underwater fluxcored wire wet welding. Journal of Materials Processing Technology 223: 124–128. 26. Hirotaira, A., and Hasegawa, M. 1978. Welding arc phenomenon (supplement). 164, Beijing, China Machine Press. 27. Hrabovsky, M., Konrad, M., Kopecky, V., and Sember, V. 1997. Processes and properties of electric arc stabilized by water vortex. IEEE Transactions on Plasma Science 25(5): 833 to 839. 28. Yushchenko, K. A., Gretskii, Y. Y., and Maksimov, S. Y. 1998. Study of physico metallurgical peculiarities of wet arc welding of structural steels. Underwater Wet Welding and Cutting, pp. 6–29. Woodhead Publishing. JUNE 2016 / WELDING JOURNAL 209-s Acknowledgments References
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