Effect of Arc Current Ultrasonic-Frequency Pulsation on Underwater Wet Arc Welding Quality

2013 ◽  
Vol 763 ◽  
pp. 174-178 ◽  
Author(s):  
Jie Zhu ◽  
Jia Cheng Guo ◽  
Wei Wang ◽  
Jia You Wang
Keyword(s):  
Arc Welding ◽  
Axial Direction ◽  
Pulse Frequency ◽  
Ultrasonic Frequency ◽  
Weld Penetration ◽  
Welding Quality ◽  
Underwater Welding ◽  
Joint Properties ◽  
Ultrasonic Assisted ◽  
Arc Current

A novel process of ultrasonic-assisted underwater wet arc welding was proposed to improve the joint properties, a number of ultrasonic-assisted underwater welding experiments were then carried out, and the effects of pulse frequency on weld formation, joint hardness and microstructure were investigated. Experimental results show that the ultrasonic frequency pulsation of arc can improve weld penetration while reducing effectively the hardness of joint HAZ in the arc axial direction and refining the grain of microstructure, and the effects of which are related closely to the pulse frequency.

The Effect of Hybrid Ultrasonic Pulse Current Parameters on VPTIG Arc Pressure and Weld Formation

2011 ◽  
Vol 704-705 ◽  
pp. 770-774 ◽  
Author(s):  
Bo Jin Qi ◽  
Wei Li ◽  
Bao Qiang Cong ◽  
Ming Xuan Yang
Keyword(s):  
Arc Welding ◽  
Pulse Current ◽  
Welding Process ◽  
Pulse Frequency ◽  
Ultrasonic Pulse ◽  
Duty Ratio ◽  
Weld Penetration ◽  
Weld Formation ◽  
Arc Pressure ◽  
Proper Frequency

Based on a novel arc welding device which can provide hybrid ultrasonic pulse current, the effect of hybrid pulsed current parameters on the arc pressure and weld formation during the aluminum alloy welding process was investigated. The experiment results show that, compared with normal VPTIG process, hybrid ultrasonic pulse VPTIG process gets greater arc pressure. Under the condition of keeping the RMS of positive current unchanged, lowering duty ratio has an evident effect on increasing arc pressure. At proper frequency range, increasing the pulse frequency and decreasing the pulse duty ratio can increase the depth and width of the weld, improve weld penetration rate correspondingly, and be beneficial to improve weld quality.

scholarly journals Numerical Analysis of Keyhole and Weld Pool Behaviors in Ultrasonic-Assisted Plasma Arc Welding Process

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 703
Author(s):  
Junnan Qiao ◽  
Chuansong Wu ◽  
Yongfeng Li
Keyword(s):  
Shear Stress ◽  
Weld Pool ◽  
Arc Welding ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Arc Pressure ◽  
Ultrasonic Assisted

The acoustic radiation force driving the plasma jet and the ultrasound reflection at the plasma arc-weld pool interface are considered to modify the formulas of gas shear stress and plasma arc pressure on the anode surface in ultrasonic-assisted plasma arc welding (U-PAW). A transient model taking into account the dynamic changes of heat flux, gas shear stress, and arc pressure on the keyhole wall is developed. The keyhole and weld pool behaviors are numerically simulated to predict the heat transfer and fluid flow in the weld pool and dynamic keyhole evolution process. The model is experimentally validated. The simulation results show that the acoustic radiation force increases the plasma arc velocity, and then increases both the plasma arc pressure and the gas shear stress on the keyhole wall, so that the keyholing capability is enhanced in U-PAW.

scholarly journals Optimization of Ultrasonic-Assisted Extraction, Characterization, and Antioxidant Activities of Polysaccharides From Sojae Semen Praeparatum

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110206
Author(s):  
Yongshuai Jing ◽  
Ruijuan Zhang ◽  
Lan Li ◽  
Danshen Zhang ◽  
Yu Liu ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Deae Cellulose ◽  
Chemical Compositions ◽  
Hydroxyl Groups ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Assisted Extraction ◽  
Ultrasonic Time ◽  
Ultrasonic Assisted ◽  
Ultrasonic Assisted Extraction

In this study, response surface methodology (RSM) was used to optimize the ultrasonic-assisted extraction parameters of Sojae Semen Praeparatum polysaccharides (SSPP-80), the optimum conditions were determined as follows: ultrasonic frequency of 100 W, ultrasonic power of 80 Hz, ultrasonic temperature of 52℃, ultrasonic time of 23 minutes, and liquid to raw material ratio of 40 mL/g. Based on these conditions, polysaccharides extraction rate was 7.72% ± 0.26%. Then, 2 novel polysaccharides (SSPP-80‐1, SSPP-80‐2) were isolated from SSPP by DEAE-cellulose 52 chromatography. The chemical compositions, physicochemical properties, and structure of SSPPs were investigated by simultaneous thermal analyzer (TGA), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FI-IR), and high-performance liquid chromatography (HPLC). The results showed that SSPP-80 and 2 fractions were mainly composed of mannose (Man), glucose (Glc), galactose (Gal), xylose (Xyl), and arabinose (Ara). In addition, the antioxidant activities were evaluated against the DPPH and hydroxyl radical in vitro, the IC50 of SSPP-80, SSPP-80‐1 and SSPP-80‐2 against DPPH free radical were 4.407, 8.267, and 5.204 mg/mL, respectively, whereas the IC50values for removing hydroxyl groups were 5.318, 3.516, and 4.016 mg/mL, respectively. It demonstrated that SSPP-80 and 2 fractions had certain antioxidant activity. Theoretical basis for use of Sojae Semen Praeparatum polysaccharides was provided by this study.

Numerical Simulation of Plunge Force During the Plunge Phase of Friction Stir Welding and Ultrasonic Assisted FSW

2008 ◽  
Author(s):  
Kwanghyun Park ◽  
Bongsuk Kim ◽  
Jun Ni
Keyword(s):  
Numerical Simulation ◽  
Friction Stir Welding ◽  
High Frequency ◽  
Hybrid Welding ◽  
Ultrasonic Vibrations ◽  
Welding Quality ◽  
Friction Stir ◽  
Ultrasonic Assisted ◽  
Welding Force ◽  
Welding Technique

Ultrasonic assisted friction stir welding (UaFSW) is an hybrid welding technique, where high frequency vibration is superimposed on the movement of a rotating tool. The benefit of using ultrasonic vibration in the FSW process refers to the reduction in the welding force and to the better welding quality. The UaFSW system is being developed and its mechanism needs to be understood using both the experiments and the numerical simulations. In this paper, FE simulations of FSW and UaFSW using ABAQUS/Explicit were carried out to examine plunge forces during the plunge phase of FSW and UaFSW, respectively. First, the simulations of the conventional FSW process were validated. Then, simulation of UaFSW process was performed by imposing sinusoidal horizontal ultrasonic vibrations on the tool.

Effect of pulse frequency on droplet transfer and weld formation in local dry underwater welding

2021 ◽  
Vol 68 ◽  
pp. 1726-1734
Author(s):  
Zhenmin Wang ◽  
Kai Pei ◽  
Leigang Han ◽  
Haodong Wu ◽  
Sanbao Lin ◽  
...  
Keyword(s):  
Pulse Frequency ◽  
Droplet Transfer ◽  
Underwater Welding ◽  
Weld Formation

Vision sensing and feedback control of weld penetration in helium arc welding process

2021 ◽  
Vol 72 ◽  
pp. 168-178
Author(s):  
Guodong Peng ◽  
Baohua Chang ◽  
Guoqing Wang ◽  
Yanjun Gao ◽  
Runshi Hou ◽  
...  
Keyword(s):  
Feedback Control ◽  
Arc Welding ◽  
Welding Process ◽  
Weld Penetration ◽  
Vision Sensing ◽  
Arc Welding Process

Development of Exothermic Flux for Enhanced Penetration in Submerged Arc Welding

2020 ◽  
Vol 19 (01) ◽  
pp. 131-146
Author(s):  
Aditya Kumar ◽  
Kulwant Singh
Keyword(s):  
Mathematical Model ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Graphical Form ◽  
Welding Parameters ◽  
Weld Penetration ◽  
Agglomeration Process ◽  
Arc Welding Process ◽  
Submerged Arc

An exothermic flux for submerged arc welding process has been developed which is capable of enhancing weld penetration of the joint. For this purpose, thermit mixture in different proportions (20% and 40%) has been added to the parent flux by agglomeration process. Beads on plate were deposited using parent and developed exothermic fluxes for a comparative study. EH14 filler wires in combination with parent and exothermic fluxes were used in this investigation. The effects of welding parameters and exothermic flux on weld penetration were investigated and the results have been presented in this paper. It has been found that the penetration increases from 2.95 to 3.51[Formula: see text]mm with 40% thermit mixture addition to the parent flux. It is further observed that penetration increases with increase in the amount of thermit mixture added. A mathematical model has been developed to predict weld penetration or select suitable welding parameters to obtain the desired penetration. The significance of coefficients was tested using Student’s [Formula: see text]-test and the adequacy of developed model was tested using [Formula: see text]-test. The effects of various parameters on penetration have been presented in graphical form for better understanding.

Sign in / Sign up

Export Citation Format

Share Document