Arc Characteristics and Droplet Transfer Analysis of Disconnect Impulse Arc Welding for Repairing Surface Default of Metal Parts

2014 ◽  
Vol 941-944 ◽  
pp. 2026-2029 ◽  
Author(s):  
Jun Wei Yang ◽  
Jia Xu Teng ◽  
Qing Zhang ◽  
Ling Dong Meng
Keyword(s):  
Arc Welding ◽  
Droplet Transfer ◽  
Metal Parts ◽  
Transfer Characteristics ◽  
Camera Systems ◽  
Arc Characteristics ◽  
Wire Material ◽  
Metallurgical Bonding ◽  
Arc Current ◽  
The Wire

The wire material and the workpiece was fused together by the transient arc heat from disconnect impulse, to achieve metallurgical bonding. The process of arc striking and the arc was very short in disconnect impulse arc welding. The image signals of disconnect impulse arc and droplet transfer were acquired using speed camera systems. Then, the arc and the droplet transfer characteristics in repairing the metal defects process were discussed. The results showed that the process of arc striking was only 0.5-1ms in disconnect impulse arc welding. The maintain arc time must be matched with the arc current, the longer maintain arc time the less the arc current was likely to be.

Droplet Transfer Analysis of Intermittent Pulsed Arc Welding Used to Repair the Metal Defects

2014 ◽  
Vol 915-916 ◽  
pp. 1078-1081 ◽  
Author(s):  
Jun Wei Yang ◽  
Jia Xu Teng ◽  
Xiao Hui Zhang
Keyword(s):  
Arc Welding ◽  
Substrate Surface ◽  
Repair Process ◽  
Droplet Transfer ◽  
Pulsed Arc Welding ◽  
Transfer Mode ◽  
Camera Systems ◽  
Metallurgical Bonding ◽  
Change Of Microstructure ◽  
Pulsed Arc

Intermittent pulsed arc welding using micro heat control, it can be used to repair the defect of metal parts. But the droplet transfer mode is different from the general pulsed TIG. The image signals of intermittent pulsed droplet transfer are acquired using speed camera systems. Then, the characteristics of droplet transfer for intermittent pulsed arc welding were discussed. The results showed that in the Intermittent pulsed arc welding repair process, welding wire and substrate surface were melted by instantaneous high voltage arc and formed drop wise droplet. And with gravity and surface tension the droplet jitter, roll, and then cooled and solidified rapidly. The change of microstructure is continuous from the substrate to the droplet, showing a good metallurgical bonding.

scholarly journals Arc Characteristics and Weld Bead Microstructure of Ti-6Al-4V Titanium Alloy in Ultra-high Frequency Pulse Gas Tungsten Arc Welding (UHFP-GTAW) Process

2020 ◽  
Vol 26 (4) ◽  
pp. 426-431
Author(s):  
Wei LI ◽  
Gaochong LV ◽  
Qiang WANG ◽  
Songtao HUANG
Keyword(s):  
Titanium Alloy ◽  
Fusion Zone ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Weld Bead ◽  
Gas Tungsten Arc ◽  
Arc Characteristics ◽  
Arc Pressure ◽  
Gtaw Process ◽  
Gas Tungsten

To resolve the problem of grain coarsening occurring in the fusion zone and the heat-affected zone during conventional gas tungsten arc welding(C-GTAW) welded titanium alloy, which severely restricts the improvement of weld mechanical properties, welding experiments on Ti-6Al-4V titanium alloy by adopting ultra-high frequency pulse gas tungsten arc welding (UHFP-GTAW) technique were carried out to study arc characteristics and weld bead microstructure. Combined with image processing technique, arc shapes during welding process were observed by high-speed camera. Meanwhile the average arc pressure under various welding parameters were obtained by adopting pressure measuring equipment with high-precision. In addition, the metallographic samples of the weld cross section were prepared for observing weld bead geometry and microstructure of the fusion zone. The experimental results show that, compared with C-GTAW, UHFP-GTAW process provides larger arc energy density and higher proportion of arc core region to the whole arc area. Moreover, UHFP-GTAW process has the obviously effect on grain refinement, which can decrease the grain size of the fusion zone. The results also revealed that a significant increase of arc pressure while increasing pulse frequency of UHFP-GTAW, which could improve the depth-to-width ratio of weld beads.

The Investigation in the Influence of Hardness to Transition Point after Tempering for Boric Carbon Steels

2013 ◽  
Vol 690-693 ◽  
pp. 186-192
Author(s):  
Ho Hua Chung ◽  
Tsong Hsin Chen
Keyword(s):  
Impact Energy ◽  
Carbon Steels ◽  
Material Strength ◽  
Tempering Temperature ◽  
Material Test ◽  
Wire Material ◽  
Steel Material ◽  
The Wire ◽  
The Impact ◽  
Test Fragment

This study concerned the influence of the material strength, ductility and impact energy and the relationship of the broken section profile vs. ductile transition brittle where the steel material was treated under different tempering temperature and hardness. Generally after the steel materials, 10B35 coil wire materials which was generally applied to form screws, was treated by quenching and tempering, its hardness ranged from HRC30 to HRC45. The results showed that the elongation rate beyond 20.4% would be proportional to the impact energy with linear relation, but with reverse proportion to the hardness value. The brittle-tough point of the hardness was set around HRC37 after heat treatment in order to balance the strength and the toughness. In addition, the coil wire materials were analyzed from broken section materials showing good toughness; this represented that the area of the cross section radiation layer due to ductile fracture would largely increase. On the contrary, the wire material test fragment with bad toughness represented that the area of the shear layer due to brittle fracture would largely increase as well. As to that material, if its hardness was greater than or equal to HRC37, that material would have an excellent turning danger from transition. At the same time, when the tempering temperature of the wire steel material was set under 4600C and its corresponding central hardness was about HRC37, the distance between two cementite phase layers suddenly increased. This result leaded to the reason why the wire material test fragment was turned into brittleness from ductility. Therefore, when the fastener was manufactured under tempering treatment, avoiding the tempering brittleness temperature range was necessary.

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.

scholarly journals Control of Droplet Transition in Underwater Welding Using Pulsating Wire Feeding

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1715 ◽  
Author(s):  
Ning Guo ◽  
Lu Huang ◽  
Yongpeng Du ◽  
Qi Cheng ◽  
Yunlong Fu ◽  
...  
Keyword(s):  
Short Circuit ◽  
Droplet Transfer ◽  
Frequency Condition ◽  
Feeding Mode ◽  
Cored Wire ◽  
Underwater Wet Welding ◽  
Withdrawal Speed ◽  
Feeding Process ◽  
The Wire ◽  
Wire Feeding

Underwater wet welding technology is widely used. Because the stability of droplet transfer in underwater wet welding is poor, the feasibility of improving the droplet transfer mode has been discussed from various technical directions. In this work, the characteristics of pulsating wire feeding were studied in the pulsating wire feeding mode by investigating the effects of changing the pulsating frequency, the wire withdrawal speed, and the wire withdrawal quantity on the droplet transfer process and the welding quality. With the aim of improving weld forming and welding stability, the authors selected the coefficient of variation and the ratio of unstable droplet transfer as the indexes to evaluate the effect of droplet transfer control. The pulsating wire feeding process of underwater wet flux-cored wire was analyzed in depth, and the following conclusions were drawn: using the pulsating wire feeding mode and after comparing and analyzing the pulsed wire feeding process under the same frequency condition, the authors found that the forming and stability were better under the conditions of slower withdrawal speed and smaller withdrawal quantity. The short-circuit transition ratio decreased steadily with the increase of pulsating wire feeding frequency, the rejection transition ratio first rose and then decreased, and the splash ratio first decreased and then rose.

Argon-Arc Welding of Cu/Ti3AlC2 Cermet

2008 ◽  
Vol 368-372 ◽  
pp. 1001-1003
Author(s):  
Hua Zhang ◽  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Shi Bo Li
Keyword(s):  
Network Structure ◽  
Arc Welding ◽  
Room Temperature ◽  
Applied Pressure ◽  
Al Alloys ◽  
Welding Parameters ◽  
Arc Voltage ◽  
Arc Current ◽  
Joining Strength ◽  
Welding Technique

Joining of Cu/Ti3AlC2 cermet by an argon-arc welding technique without filler was firstly investigated. The results show that the Cu/Ti3AlC2 cermet can be joined firmly. The joining strength at room temperature was measured to be 851 MPa after optimization of the welding parameters with 2.6 A/mm2 for arc current density, 5 s for arc time, 10.8 kPa for applied pressure and 12 V for arc voltage. The microstructure in welded zone shows that fine TiCx particles uniformly dispersed in a network structure of Cu-Al alloys. This feature endows the Cu/Ti3AlC2 cermet with the high joining strength.

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