Welcome to CG Protective Clothing Company

keyhole formation and collapse in plasma arc welding

HOME PAGE   keyhole formation and collapse in plasma arc welding

keyhole formation and collapse in plasma arc welding

Whether you need flame resistant & Arc flash rated Coveralls, Jackets, Pants, Vests, Insulating Utility, Safety harness, Molten Metal Splash Protective, Electric conductive suit, Acid and alkali protective clothing or Other products, C&G Safety has you covered. Help or quote?

keyhole formation and collapse in plasma arc welding

2018-12-4 · Keyhole-mode welding is an advantage of plasma arc welding (PAW), and much research has been conducted on keyhole formation and weld pool geometry. However, researchers usually constructed equivalent heat source models to represent the actual thermal arc energy.


2003-5-16 · Keyhole plasma arc welding (PAW) (Ref. 1) offers significant advantages over conventional gas tungsten arc welding (GTAW) in terms of penetration depth, joint preparation and thermal distortion (Ref. 2). Although its energy is less dense than laser beam welding (LBW) (Ref. 3) and electron beam welding (EBW) (Ref. 3), keyhole PAW is more cost ...


2021-1-29 · Pan, L. J. Yang, and S. S. Hu, “ Numerical analysis of keyhole formation and collapse in variable polarity plasma arc welding,” Int. J. Heat Mass Transfer 109, ... “ Material flow in variable polarity plasma arc keyhole welding of aluminum alloy,” J. Manuf. Processes 36, 480 ...


2018-7-16 · Keyhole formation and collapse in plasma arc welding H G Fan and R Kovacevic Department of Mechanical Engineering, Southern Methodist University, Dallas, TX 75275, USA Received 8 June 1999, in final form 26 August 1999 Abstract. A mathematical model is developed to describe the heat transfer and fluid flow in stationary keyhole plasma arc welding.


Abstract In this study, the formation process of welding defects in plasma keyhole arc welding was investigated based on the formation of eddies inside the weld pool. An experimental approach using an advanced X-ray visualization system was employed to clarify this relationship. The results indicated that two large eddies are produced in the weld pool.


2013-1-1 · Due to the moving of the plasma torch, the plasma arc may lose more energy and force along the welding direction, and the plasma column itself may become oblate. The deformed plasma results in an oblate keyhole shape, especially at the keyhole exit …


2013-10-1 · In plasma arc welding, the plasma arc pressure is the main driving force to produce a keyhole, while in laser beam welding the recoil pressure due to intensive metal vapor dominates the keyhole formation. Thus, the keyhole in laser beam welding has …


This paper seeks to clarify the weld pool formation process in plasma keyhole arc welding (PKAW). We adopted, for the first time, the measurement of the 3D convection inside the weld pool in PKAW by stereo synchronous imaging of tungsten tracer particles using two sets of x-ray transmission systems. The 2D convection on the weld pool surface was also measured using zirconia tracer particles.


2014-1-4 · Fan HG, Kovacevic R (1999) Keyhole formation and collapse in plasma arc welding. J Phys D Appl Phys 32:2902–2909. Article Google Scholar 6. Martikainen JK, Moisio TJI (1993) Investigation of the effect of welding parameters on weld quality of plasma arc keyhole welding …


2018-11-12 · the keyhole formation in the keyhole plasma arc welding process To cite this article: Dongsheng Wu et al 2019 J. Phys. D: Appl. Phys. 52 165203 View the article online for updates and enhancements. Recent citations Coupled mechanisms of arc, weld pool and weld microstructures in high speed tandem TIG welding Dongsheng Wu et al-


2019-3-1 · Elucidation of the weld pool convection and keyhole formation mechanism in the keyhole plasma arc International Journal of Heat and Mass Transfer ( IF 5.584) Pub Date : 2019-03-01, DOI: Dongsheng Wu, Anh Van Nguyen, Shinichi Tashiro, Xueming Hua, Manabu Tanaka


2015-10-1 · China Welding, 2014, 23(3):9-15 7、Liu Z M , Wu C S and Gao J Q. Vision-based observation of keyhole geometry in plasma arc welding. International Journal of Thermal Sciences, 2013, 63: 38-45 8、张转转,武传.


2016-2-19 · The flow of gas is very critical in Keyhole plasma welding as well as the speed of torch or job travel . This has to be very precise and controlled or the keyhole will collapse causing the weld to be rejected . This is indicated most in circumferential welding when initiation and shutting down of the arc has to be controlled in a manner where ...


1999-11-21 · A mathematical model is developed to describe the heat transfer and fluid flow in stationary keyhole plasma arc welding. Using the volume of fluid method, the processes of heating, melting, collapsing and subsequent solidifying in the molten pool are dynamically studied.


2009-8-21 · Multipass welding Single pass welding of thick sections Arc stability Reduced arc stability at higher welding speeds leads to humping Keyhole instability Interaction between laser and arc stabilises the arc Ribic et al. Problems and issues in laser-arc hybrid welding International Materials Reviews 2009 VOL 54 NO 4 225


2019-11-14 · Plasma welding using the “keyhole technique”. Current levels can vary from 15 to 350 amperes, depending on the thickness of the material. Keyhole plasma welding. In keyhole plasma welding, the plasma arc drills a hole in the very tightly closed seam. By moving the plasma torch with a very clean movement, the seam will immediately close again.


In the previous work, low-power laser/arc hybrid welding technique is used to weld magnesium alloy and high-quality weld joints are obtained. In order to make clear the interactions between low-power laser pulse and arc plasma, the effect of arc plasma on laser pulse is studied in this article. The result shows that the penetration of low-power laser welding with the assistance of TIG arc is ...


in Plasma Keyhole Arc Welding b yNg ue nV a h*,S iic T s iro B H ** and M bu T k * This investigation is purposed to clarify the influence of pilot gas composition to convective pattern on the weld pool surface in Plasma keyhole arc welding process.


2003-5-16 · An efflux plasma charge sensor is proposed to monitor weld joint penetration in keyhole plasma arc welding. For convenience of application, the sensor is integrated as part of the fixture. Based on experimental data, a linear model is fit to estimate the joint penetration from the output of the sensor.


2009-8-21 · brittle phases,20–22 cracks,23 thermal distortion12,24,25 and porosity13,26–28 compared to both laser and arc welds. One of its main advantages involves the ability to bridge gaps between workpieces in excess of that possible during laser welding.19,29–35 Finally, the combi- nation of the laser and the arc in hybrid welding allows


2014-12-10 · Fan HG, Kovacevic R (1999) Keyhole formation and collapse in plasma arc welding. J Phys D Appl Phys 32:2902–2909. Article Google Scholar 13. Li TQ, Wu CS, Feng YH, Zheng LC (2012) Modeling of the thermal fluid flow and keyhole shape in stationary plasma arc welding…


2021-7-30 · the keyhole behavior, porosity and fluid flow dynamic were employed in metal AM processes in the UK [9,10], the US [11,12] and Japan [13,14]. Plasma arc welding (PAW) is one advanced joining technology with superior characteristics such as: high current density, constricted arc plasma, and high plasma jet velocity.


2018-2-1 · Abstract. Keyhole plasma arc welding is superior to other ordinary arc welding technologies in deep penetration welding. Energy can be transferred to bottom metal by hot plasma arc in keyhole rather than merely by heat conduction through whole thickness. Hence, an evolutionary keyhole-mode heat transfer model was developed to demonstrate this ...


2018-6-29 · AbstractKeyhole welding with the plasma arc welding process occurs when the engineered nozzle and the plasma gas flowrate impart the arc pressure and heat distribution necessary for the formation of a keyhole weld pool. Experimental …


2002-6-18 · At laser powers of 500 W and greater, the protrusion occurs on the keyhole wall, which results in keyhole collapse and void formation at the bottom. Initiation of the protrusion is caused mainly by collision of upward and downward flows due to the pressure components, and Marangoni flow has minor effects on the flow patterns and keyhole stability.


As the energy and force of the plasma arc accumulating, a keyhole forms and increases in size, and the temperature and flow field of the molten pool change constantly. Through numerical results, the study found that the keyhole formation could be divided into three stages.


A three-dimensional and transient model with keyhole geometry-dependent heat source and arc pressure distribution is developed for plasma arc welding process. The influence of the keyhole evolution on heat flux and arc pressure distribution on the keyhole wall is taken into consideration. The dynamic variation of the temperature field and fluid flow in the weld pool as well as the keyhole ...


2019-6-1 · mechanism of the plasma arc, weld pool and keyhole in plasma arc welding Xiaoxia Jian, ChuanSong Wu, Guokai Zhang et al.-Sensing of weld pool surface using non-transferred plasma charge sensor W Lu, Y M Zhang and John Emmerson-Experimental investigation on the weld pool formation process in plasma keyhole arc welding Nguyen Van Anh, Shinichi ...


This investigation aims to discuss the formation process of eddies and the heat transportation in plasma keyhole arc welding. In order to clarify this issue, the measurement of the convection inside the weld pool, the convection on the weld pool surface, also the temperature distribution on the weld pool surface were carried out. The results showed that two eddies were found in the weld pool ...


2011-4-14 · late the keyhole formation and collapse in the laser welding pro-cess. This work included the calculation of temperature field distributions, pressure balance, melt flow, free surface, laser-induced plasma, and multiple reflections. The model predictions are in good agreement with the experimental results. In this paper,


2011-4-14 · experiments to investigate porosity formation in pulsed laser welding [5–7]. Based on these experimental observa-tions, it was found that the formation of porosity has a close relationship with keyhole dynamics and the collapse of the keyhole right after the termination of laser irradia-tion. In pulsed laser welding, during the keyhole formation


2017-6-1 · Arc pressure is one of the most important factors as the keyhole is produced and maintained mainly by the arc force in VPPA welding. The plasma arc force, P a, including the arc pressure generated by the magnetic field and the dynamic pressure generated by the flow of the plasma gas, can be expressed as: (22) P a = μ 0 I 2 4 π 2 1 r 2 2-1 r 1 2 + C j 1 2 σ j 2 exp-r 2 2 σ j 2 (DCEN phase: I = I …


2013-6-15 · The keyhole mode of plasma arc welding (PAW) can penetrate thicker workpieces with a single pass and produce welds with high aspect ratio. Compared to laser beam welding and electron beam welding, keyhole PAW is more cost effective and more tolerant of joint preparation [1, 2].Thus, keyhole PAW has found wide applications in industry [3–7]. ...


Weld Formation Stability and Force in Variable Polarity Plasma Arc Keyhole Welding HAN Yong-quan1,GUO Long1,CHEN Shu-jun2,DU Mao-hua1,WU Yong-jun1 (1 Materials Forming Key Laboratory,Inner Mongolia University of Technology, Hohhot 010051,China;2 College of Mechanical Engineering and Applied Electronics Technology,Beijing University of ...


2020-7-21 · Coupling discharge between keyhole plasma and arc plasma in laser-arc welding of Mg alloy. IEEE Transactions on Plasma Science, 2014, 42(5):1400-1406. ( SCI 检索) 6. Minghua Chen, Xueyuan Li, Liu*. Effect of electric field on interaction


2019-6-1 · As an extension of gas tungsten arc welding, plasma arc welding (PAW) uses a constricting nozzle/orifice to create a plasma arc that has a higher heat density. This increased heat density not only provides higher arc temperatures but also a much stronger arc force [1–3]. Due to its high energy density and its high-velocity plasma jet, the PAW process can operate in the keyhole mode. In this mode, the plasma …


Plasma keyhole welding is mainly found in stainless steel construction, tank, pipeline and chemical apparatus construction. The wall thicknesses to be joined are generally in the range between 3.0 mm and 10.0 mm. Typical applications here are I-butt welding of longitudinal and circular seams of "thick-walled" pipes, vessels and bottoms. For material thicknesses> 10mm, plasma welding is often ...


2020-2-6 · Plasma arc welding (PAW) is a fusion arc welding process PKAW. Due to the much higher heat flux and arc pressure [1, 2] which can be categorized as either the melt-in or key-hole mode (plasma keyhole arc welding—PKAW) [3]. The PKAW process is characterized by a ‘keyhole’ inside the weld pool. The plasma arc from the torch impinges on the


Please contact us if you want to have your FR clothing tailored. Contact Us Now

Have Questions or Need a Custom Quote?