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Acta Metall Sin  2016, Vol. 52 Issue (1): 93-99    DOI: 10.11900/0412.1961.2015.00204
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ARC BEHAVIOR AND JOINTS PERFORMANCE OF CMT WELDING PROCESS IN HYPERBARIC ATMOSPHERE
Jiqiang HUANG1(),Long XUE1,Junfen HUANG1,Yong ZOU1,Huli NIU2,Deyu TANG2
1 Opto-Mechatronic Equipment Technology Beijing Area Major Laboratory, Beijing Institute of Petrochemical Technology, Beijing 102617, China
2 Research Institute of Engineering Technology, China National Petroleum Corporation, Tianjin 300451, China
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Abstract  

Underwater hyperbaric dry welding method is one of the key technology for emergency repair of underwater pipeline leakage. Since the ambient pressure grows with water depth for application of the underwater dry hyperbaric welding method, the normal GMAW welding process tends to be unstable with the increase of the ambient pressure, which leads to the decline in the quality of welding. The cold metal transfer (CMT) welding method adopts a push-pull wire feeding mode and it has adaptive ability to control droplet transfer. In order to improve the welding quality under the hyperbaric environment, the experiments using the CMT welding method were conducted in atmospheric pressure (0.1 MPa) and 0.5 MPa environmental pressures respectively with a test system simulating the underwater hyperbaric environment. API X65 pipes were used as the base metal for welding experiments. A high-speed video camera was used to monitor the behavior of the welding arc. The welding processes at both ambient pressures were found to be stable. However, compared with the atmospheric environment, the CMT welding arc contracted at the ambient pressure of 0.5 MPa, and the droplet transfer frequency was reduced a little. Mechanical performance tests and microstructure analysis of the welds were carried out after welding. While welding in the hyperbaric environment, the upper bainite structure emerged in the microstructure of the seam and the heat-affected zone (HAZ) because of the enhanced environmental cooling effect. The tensile properties of the welds were not changed significantly. Although the low temperature impact toughness decreased, the test data were higher than the relevant limitations of standard. The experimental results show that the stability of the welding process is improved by applying the CMT welding method in the hyperbaric environment. It was verified that the CMT welding method can meet the requirements of underwater hyperbaric welding.

Key words:  hyperbaric dry welding      cold metal transfer (CMT)      welding arc      microstructure      underwater welding     
Received:  08 April 2015     
Fund: Supported by National Natural Science Foundation of China (No.51275051) and Innovation and Improvement Plan of Beijing Education Commission (No.TJSHG201510017023)

Cite this article: 

Jiqiang HUANG,Long XUE,Junfen HUANG,Yong ZOU,Huli NIU,Deyu TANG. ARC BEHAVIOR AND JOINTS PERFORMANCE OF CMT WELDING PROCESS IN HYPERBARIC ATMOSPHERE. Acta Metall Sin, 2016, 52(1): 93-99.

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2015.00204     OR     https://www.ams.org.cn/EN/Y2016/V52/I1/93

Fig.1  Schematic of hyperbaric welding equipment
Material C Si Mn P S Cu Ni Cr Ti B Fe
Base metal 0.07 0.28 1.19 0.006 0.003 0.10 0.04 0.25 - - Bal.
Welding wire 0.08 0.08 1.76 0.014 0.004 - - - 0.09 0.004 Bal.
Table 1  Components of base metal and welding wire in hyperbaric dry welding experiments
Material Yield strength / MPa Tensile strength / MPa Extensibility / % Charpy impact energy / J
Base metal 515 615 44 135
Welding wire 500 610 25 128
Table 2  Performances of base metal and welding wire used in hyperbaric dry welding experiments
Pressure Zone Current Voltage Swing amplitude Welding speed Flow rate of shielding gas
MPa A V mm (cmmin-1) (Lmin-1)
0.1 Root pass 135 16.0 2~3 22 18~22
Filling bead 155 16.5 4~6 12~15 18~22
Cover pass 180 19.1 8~9 12~15 18~22
0.5 Root pass 135 17.5 2~3 22 18~22
Filling bead 155 18.5 4~6 12~15 18~22
Cover pass 185 20.5 8~9 12~15 18~22
Table 3  Parameters of cold metal transfer (CMT) welding experiments in different environment pressures
Fig.2  Pictures of high speed camera for CMT welding process with atmospheric pressure (0.1 MPa) (a) and 0.5 MPa environmental pressure (b)
Fig.3  Pictures of pipe joints welded in atmospheric pressure (0.1 MPa) (a) and 0.5 MPa environmental pressure (b)
Fig.4  OM images of root pass (a), filling bead (b), cover pass (c) and heat affected zone (HAZ) (d) of joint welded in atmospheric pressure (0.1 MPa)
Fig.5  OM images of root pass (a), filling bead (b), cover pass (c) and heat affected zone (d) of joint welded in 0.5 MPa environmental pressure
Pressure / MPa Tensile strength / MPa Extensibility / % Broken area Limitation of standard / MPa
0.1 565 14 Weld 531
562 12 Weld 531
0.5 545 11 Weld 531
570 14 Weld 531
Table 4  Transverse tension tests parameters of joints welded in atmospheric (0.1 MPa) and 0.5 MPa environmental pressure
Pressure Position of Impact Least impact Mean impact Limitation of standard
MPa Charpy notch energy energy energy Least impact Mean impact
J J J energy / J energy / J
0.1 Weld 144, 133, 137 133 138 27 34
HAZ 107, 127, 84 84 106 27 34
0.5 Weld 57, 47, 78 47 61 27 34
HAZ 71, 155, 67 67 98 27 34
Table 5  Charpy impact energy tests (-20 ℃) parameters of joints welded in atmospheric (0.1 MPa) and 0.5 MPa environmental pressure
[1] Jiang L P, Wang Z H, Jiao X D, Zhou C F, Fang X M, Ma H X. Trans China Weld Inst, 2007; 28(6): 1
[1] (蒋力培, 王中辉, 焦向东, 周灿丰, 房晓明, 马洪新. 焊接学报, 2007; 28(6): 1)
[2] Shi Y W,Zhang X P,Lei Y P. Welding Technology in Special Conditions. Beijing: China Machine Press, 2000: 1
[2] (史耀武,张新平,雷永平. 严酷条件下的焊接技术. 北京: 机械工业出版社, 2000: 1)
[3] Song B T. Underwater Welding and Cutting. Beijing: China Machine Press, 1989: 5
[3] (宋宝天. 水下焊接及切割. 北京: 机械工业出版社, 1989: 5)
[4] Woodward N J. Welding J, 2006; 85(10): 35
[5] Marino R, Blackman S A, Woodward N J. Pipeline World, 2004; 25(6): 11
[6] Suga Y. Welding under Extreme Conditions. Oxford: Pergamon Press, 1989: 207
[7] Richardson I M, Woodward N J, Billingham J. In: Jin S C, Matsui T, Chen J W, Kyozuka Y eds., Proc of 12th Int Conf on Offshore and Polar Arctic Engineering, Kitatyushu: International Society of Offshore and Polar Arctic Engineering, 2002: 295
[8] Dos Santos J F, Manzenrieder H, Cui H, Recoschewitz J. In: Jin S C ed., Proc of 6th Int Conf on Offshore and Polar Arctic Engineering, San Francisco: International Society of Offshore and Polar Arctic Engineering, 1992: 163
[9] Mallieswaran A, Pugazhendhi A, Azhagarasan S. J Adv Technol Eng, 2012; 1(1): 71
[10] Zhao B, Wu C S, Jia C B, Yuan X. Acta Metall Sin, 2013; 49: 797
[10] (赵 博, 武传松, 贾传宝, 袁 新. 金属学报, 2013; 49: 797)
[11] Odd M A, Hans F, Ansgar H. Weld J, 2006; 85(6): 52
[12] Xue L, Wang Z H, Zhou C F, Jiao X D. Trans China Weld Inst, 2006; 27(12): 17
[12] (薛 龙, 王中辉, 周灿丰, 焦向东. 焊接学报, 2006; 27(12): 17)
[13] Zhou C F, Jiao X D, Xue L, Chen J Q, Fang X M, Wang W Y. Trans China Weld Inst, 2007; 28(2): 5
[13] (周灿丰, 焦向东, 薛 龙, 陈家庆, 房晓明, 王维越. 焊接学报, 2007; 28(2): 5)
[14] Hart P, Richardson I M, Nixon J H. Welding World, 2001; 45(11/12): 29
[15] Hart P. Welding Res Abroad, 2001; 49(3): 29
[16] Akselsen O M, Fostervoll H, Carl H A. In: Jin S C ed., Proc of 18th Int Conf on Offshore and Polar Arctic Engineering, Vancouver: International Society of Offshore and Polar Arctic Engineering, 2008: 246
[17] Akselsen O M, Fostervoll H, Ahlen C H. Int J Offshore Polar Eng, 2010; 20: 110
[18] Azar A S, Woodward N, Fostervoll H, Akselsen O M. J Mater Process Technol, 2012; 21(2): 211
[19] Huang J Q, Xue L, Lu T, Niu H L, Tang D Y, Jiang L P. China Welding, 2012; 21(4): 26
[20] Woodward N J. Int J Offshore Polar Eng, 2014; 24: 206
[21] Paidar M, Khodabandeh A, Najafi H, Alireza S R. Int J Adv Manufacture Technol, 2015; 80(1): 183
[22] Yin S Y. Process and Application of Gas Shielded Arc Welding. 2nd Ed., Beijing: China Machine Press, 2012: 441
[22] (殷树言. 气体保护焊工艺基础及应用, 第2版. 北京: 机械工业出版社, 2012: 441)
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