Investigation of Arc Bubble Affecting the Arc Stability and Improvement of Weld Appearances Using Bubble Constraint Device in Underwater Wet Welding

2019 ◽  
Vol 972 ◽  
pp. 215-221
Author(s):  
Hao Chen ◽  
Ning Guo ◽  
Ji Cai Feng ◽  
Guo Dong Wang
Keyword(s):  
Real Time ◽  
Transfer Process ◽  
Welding Process ◽  
Electric Signal ◽  
Process Stability ◽  
Droplet Transfer ◽  
Transfer Mode ◽  
Arc Stability ◽  
Weld Appearance ◽  
The Impact

The generating, floating and collapsing of arc bubble is a special phenomenon in underwater flux-cored wet welding. The configuration changing process of bubble will change the stress on droplet and influence the droplet transfer process. In this study, the shape changing of bubble is captured in graphic and the real-time electric signal data is obtained. The impact of bubble floating and collapsing results in the globular repelled transfer mode, which also reduces the arc stability. A self-designed gas-shield cover is used as a bubble constraint device to improve the welding process stability and weld appearances by limiting the free floating and expansion of arc bubble. The relationships between the cover diameter and the characteristics of weld appearance are studied.

scholarly journals Effect of Filling Rate on Underwater Wet Welding Process and Weld Appearance

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1061 ◽  
Author(s):  
Xin Zhang ◽  
Ning Guo ◽  
Changsheng Xu ◽  
Haoran Kan ◽  
Yanbo Tan ◽  
...  
Keyword(s):  
Surface Tension ◽  
Molten Pool ◽  
Welding Process ◽  
Electric Signal ◽  
Radius Of Curvature ◽  
Filling Rate ◽  
Welding Pool ◽  
Transfer Mode ◽  
Arc Stability ◽  
Flux Cored Arc Welding

Real-time electric signal, matter transfer mode and welding pool behavior were obtained to investigate the effect of wires’ filling rate on arc stability and joints’ appearance during underwater wet flux-cored arc welding (FCAW). The electric signal results showed that arc stability first decreased and then increased rapidly because the raise of filling rate affected the number of charged particles and the electrical conductivity of welding arc atmosphere. Two typical transfer modes, globular repelled transfer mode and surface tension transfer mode, were observed in this study. The ratio of surface tension transition could be increased by adding wires’ filling rate. Meanwhile, the geometry of molten pool was changed and the distance between droplets to welding pool reduced as the filling rate increased. The fusion line became more regular and the radius of curvature increased under the effect of bubbles in the molten pool. As the filling rate improving, more slags on the welds surface were acquired and the welds were much flatter and smoother.

Mechanically assisted droplet transfer process in gas metal arc welding

2002 ◽  
Vol 216 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Y Wu ◽  
R Kovacevic
Keyword(s):  
Transfer Process ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Droplet Transfer ◽  
Macroscopic Appearance ◽  
Transfer Mode ◽  
Metal Arc Welding ◽  
Separate Control

Gas metal arc welding has been generally accepted as the preferred joining technique due to its advantages in high production and automated welding applications. Separate control of arc energy and arc force is an essential way to improve the welding quality and to obtain the projected metal transfer mode. One of the most effective methods for obtaining separate control is to exert an additional force on the metal transfer process. In this paper, the droplet transfer process with additional mechanical force is studied. The welding system is composed of an oscillating wire feeder. The images of molten metal droplets are captured by a high-speed digital camera, and both the macroscopic appearance and the cross-sectional profiles of the weld beads are analysed. It is shown that the droplet transfer process can be significantly improved by wire electrode oscillation, and a projected spray transfer mode can be established at much lower currents. By increasing the oscillation frequency, the droplet transfer rate increases while the droplet size decreases. In addition, the improvement in the droplet transfer process with wire oscillation leads to an enhancement of the surface quality and a modification of the geometry of the weld beads that could be of importance for overlay cladding and rapid prototyping based on deposition by welding.

Effect of ultrasonic pattern on weld appearance and droplet transfer in ultrasonic assisted MIG welding process

2018 ◽  
Vol 35 ◽  
pp. 368-372 ◽  
Author(s):  
Chao Chen ◽  
Chenglei Fan ◽  
Sanbao Lin ◽  
Xiaoyu Cai ◽  
Lei Zhou ◽  
...  
Keyword(s):  
Welding Process ◽  
Mig Welding ◽  
Droplet Transfer ◽  
Weld Appearance ◽  
Ultrasonic Assisted

scholarly journals Analysis of the Covered Electrode Welding Process Stability on the Basis of Linear Regression Equation

2014 ◽  
Vol 59 (3) ◽  
pp. 905-909
Author(s):  
J. Słania ◽  
B. Ślązak
Keyword(s):  
Linear Regression ◽  
Welding Process ◽  
Welding Current ◽  
Process Stability ◽  
Arc Voltage ◽  
Welding Arc ◽  
Instantaneous Values ◽  
Welding Properties ◽  
The Impact ◽  
Coated Electrodes

Abstract The article presents the process of production of coated electrodes and their welding properties. The factors concerning the welding properties and the currently applied method of assessing are given. The methodology of the testing based on the measuring and recording of instantaneous values of welding current and welding arc voltage is discussed. Algorithm for creation of reference data base of the expert system is shown, aiding the assessment of covered electrodes welding properties. The stability of voltage–current characteristics was discussed. Statistical factors of instantaneous values of welding current and welding arc voltage waveforms used for determining of welding process stability are presented. The results of coated electrodes welding properties are compared. The article presents the results of linear regression as well as the impact of the independent variables on the welding process performance. Finally the conclusions drawn from the research are given.

Effect of laser on droplet transfer and welding process stability in hybrid laser + double arc welding

2016 ◽  
Vol 89 (9-12) ◽  
pp. 2981-2991 ◽  
Author(s):  
Xiaoyan Gu ◽  
Huan Li ◽  
Xiaobao Jiang ◽  
Hongchao Sheng ◽  
Xueming Wan
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Process Stability ◽  
Droplet Transfer

Effect of Arc Length on Weld Appearance and Metal Transfer in Twin-Wire GMAW Process

2012 ◽  
Vol 472-475 ◽  
pp. 1279-1282 ◽  
Author(s):  
Huan Ming Chen ◽  
Shao Jie Wu
Keyword(s):  
Transfer Process ◽  
Arc Welding ◽  
High Speed ◽  
Metal Transfer ◽  
High Speed Camera ◽  
Arc Length ◽  
Process Stability ◽  
Spray Transfer ◽  
Weld Appearance ◽  
Globular Transfer

The experiments were performed with the twin-wire GMAW machine of Fronius product. The metal transfer process and the arc shapes were observed by use of shadowgraph technique with a high-speed camera. When the arc length increases during twin-wire CO2 arc welding, the mode of metal transfer changes from short-circuiting transfer to globular transfer, and to spray transfer. But it is difficult to form a stable spray transfer process, and the weld appearance becomes worse. The short-circuiting transfer in twin-wire CO2 arc welding can improve the process stability.

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