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Suck-joo Na - One of the best experts on this subject based on the ideXlab platform.
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Analysis of molten pool behavior by flux-wall guided metal transfer in low-current submerged Arc Welding Process
International Journal of Heat and Mass Transfer, 2017Co-Authors: Degala Venkata Kiran, Suck-joo NaAbstract:Abstract A three-dimensional numerical heat transfer and fluid flow model is developed to understand the temperature distribution and molten pool behavior in a low-current submerged Arc Welding Process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, this paper suggests a flux wall boundary model to simulate flux-wall guided transfer for a single-wire low-current submerged-Arc Welding Process. This study simulates how porosity can be trapped in the V-groove joint with a flux-wall guided transfer. The computed weld width and fusion-zone shape are in fair agreement with the corresponding experimental results.
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Arc interaction and molten pool behavior in the three wire submerged Arc Welding Process
International Journal of Heat and Mass Transfer, 2015Co-Authors: Degala Venkata Kiran, Woohyun Song, Suck-joo NaAbstract:Abstract A three-dimensional numerical heat transfer and fluid flow model is developed to understand the temperature distribution and molten pool behavior in a three wire submerged Arc Welding Process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, a physical model is developed to estimate the Arc center displacement. For a given Welding condition, connecting the leading electrode with direct current electrode positive polarity, the middle and trailing electrodes with trapezoidal alternating current waveform displayed deeper weld pools when compared to the sine waveforms. Within the range of Welding conditions considered in the present work, weld width is significantly influenced by the leading Arc whereas the penetration by the middle and trailing Arcs. The computed weld width and penetration are in fair agreement with the corresponding experimental results.
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molten pool behavior in the tandem submerged Arc Welding Process
Journal of Materials Processing Technology, 2014Co-Authors: Daewon Cho, Degala Venkata Kiran, Woohyun Song, Suck-joo NaAbstract:Abstract A three-dimensional numerical heat transfer and fluid flow model is developed to examine the temperature profiles, velocity fields, weld pool shape and size in a two-wire tandem submerged Arc Welding Process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, a novel scheme is proposed to handle the Arc interaction and its influence on the molten droplet transfer direction. Using the computational fluid dynamics simulations, it is found that the droplet movement and Arc forces from the leading electrode heavily affect the molten pool flow patterns and the resultant bead shapes, even though the same heat inputs are applied. The computed weld width and penetration are in fair agreement with the corresponding experimental results.
Aniruddha Ghosh - One of the best experts on this subject based on the ideXlab platform.
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Mathematical Modelling of Heat Affected Zone Width in Submerged Arc Welding Process
2018 International Conference on Computational and Characterization Techniques in Engineering & Sciences (CCTES), 2018Co-Authors: Anshul Yadav, Aniruddha Ghosh, Priya Gupta, Anil KumarAbstract:One of the most important issues faced in the submerged Arc Welding Process is the heat affected zone softening which affects the bead geometry, penetration depth and microstructure of the deposited weld metal. Therefore, the study of heat affected zone is imperative for controlling the quality of the weld. The probability of failures increases if there is a large heat affected zone which is caused by the heating and cooling cycles in the weld zone. The objective of this work is to assess the heat affected zone of welded mild steel plates through the numerical analysis and compare it with experimental results. The relation between the input parameters on heat affected zone width has also been established. The measured data of heat affected zone had excellent agreement with the predicted data from the developed model. This agreement suggests the efficacy of the developed model for predicting the HAZ characteristics in submerged Arc Welding Processes. The microstructural study of heat affected zone is also performed in this study.
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modelling and experimental validation of moving tilted volumetric heat source in gas metal Arc Welding Process
Journal of Materials Processing Technology, 2017Co-Authors: Aniruddha Ghosh, Anshul Yadav, Arvind KumarAbstract:Abstract In this work, the effect of electrode’s tilt angle on transient temperature distribution, heat affected zone width and weld bead geometry in gas metal Arc Welding Process are investigated. Experimental, microstructure and analytical modelling studies of heat affected zone and fusion zone have been performed for different electrode tilt angles. Gaussian heat density distribution and ellipsoidal heat source shape were assumed to predict the transient temperature distribution in the welded plate. The analytical model for the transient temperature distribution in the welded plate considers heat transfers from molten droplets of the filler material, moving volumetric heat source, and convective and radiative heat losses from the welded plate. Decent agreement between the predicted and the experimental temperature distribution, heat affected zone and weld bead geometry is obtained. The comparison suggested that ellipsoidal heat source shape is quite appropriate for predicting the transient temperature distribution on the welded plate for gas metal Arc Welding Process. It was found that the heat affected zone width increases with the decrease in tilt angle. Microstructural examination on samples revealed prominent grain growth in the heat affected zone, however, fine grain structure was observed in the fusion zone. The predictions for heat affected zone width and weld bead geometry are also validated with experiments performed in shop floor Welding conditions.
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Mathematical modeling of moving heat source shape for submerged Arc Welding Process
The International Journal of Advanced Manufacturing Technology, 2013Co-Authors: Aniruddha Ghosh, Himadri ChattopadhyayAbstract:An attempt is made in this paper to find out the analytical solution of the thermal field induced in a semi-infinite body by a moving heat source with Gaussian distribution by selecting appropriate inside volume for submerged Arc Welding Process. Three different types of heat source shapes in the form of oval, double ellipsoidal, and conical forms were considered and compared with the experimental result. The study shows that for heat input of submerged Arc Welding Process, the best suitable heat source shape is in the form of an oval. The study also shows two alternate ways of predicting the size of the heat-affected zone.
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Modelling of heat transfer in submerged Arc Welding Process
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2013Co-Authors: Aniruddha Ghosh, Nilkanta Barman, Himadri ChattopadhyayAbstract:In this work, an analytical model for transient temperature distribution during submerged Arc Welding for joining two steel plates is presented. The conservation of energy equation is used to represent the thermal behaviour of the submerged Arc Welding Process. A three-dimensional double-paraboloid shape for volumetric heat source with Gaussian distribution is considered for electric Arc during Welding, and a parabolic-shaped cross section for the weld pool is considered. A set of experiments is conducted to determine the geometric parameters. The final analytical solution considers effect of the electric Arc, convective heat transfer from the exposed surface and heat of molten electrode material. Subsequently, the prediction is compared with experimentally predicted temperatures where a good agreement is found.
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Analysis of the Influence of the Heat Input and Bead Volume on HAZ Hardness for Submerged Arc Welding Process of Mild Steel Plates
Advanced Materials Research, 2011Co-Authors: Aniruddha Ghosh, Somnath Chattopadhyaya, S. MukherjeeAbstract:In Submerged Arc Welding Process involves critical set of variables which are needed to control. An attempt has been made in this paper to find out- the influence of the heat input and bead volume on HAZ Hardness for Submerged Arc Welding Process of Mild steel plates. Mild steel plates are welded by changing input variables (current, voltage, travel speed, i.e. heat input) and Rockwell hardness no. has been observed on welded portion and at the zone adjacent to the welded portion. A detailed analysis of the microstructure changes is carried out to understand the HAZ softening phenomenon.
C.l. Yang - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of variable polarity vertical-up plasma Arc Welding Process
Computational Materials Science, 2007Co-Authors: Hai Wang, C.l. YangAbstract:Three-dimensional transient governing equations were developed based on conservation laws of energy, momentum and mass. These equations described physical phenomena of convection in weld pool and heat transfer in workpiece during variable polarity vertical-up plasma Arc Welding Process. Boundary conditions for the developed governing equations were given. Welding energy input for variable polarity vertical-up plasma Arc Welding Process was quantitatively expressed. Free surface deformation of the keyhole molten pool was coupled into calculation. Effect of wire filling on the geometry of molten pool and weld reinforcement was considered in the simulation. Correlations of temperature and thermophysical properties for aluminum alloy 2219 were quantitatively established. A control volume based finite difference method was used to solve the discrete governing equations. Moreover, dynamic evolutions of geometrical profile, dimension and fluid flow for the molten pool and keyhole were simulated through the developed computational routines, which achieved transient solution of fluid flow field coupling with thermophysical properties, temperature field and weld pool free surface deformation. Besides, the effect of the workpiece thickness on the moments of keyhole formation and stable keyhole establishment was analyzed, and thermal cycles for the main Welding stage were calculated. In addition, experiments via variable polarity vertical-up plasma Arc Welding technique were conducted, and the established models were experimentally verified through weld cross-section profiles.
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Numerical simulation of variable polarity vertical-up plasma Arc Welding Process
Computational Materials Science, 2007Co-Authors: H.-x. Wang, Y.-h. Wei, C.l. YangAbstract:Three-dimensional transient governing equations were developed based on conservation laws of energy, momentum and mass. These equations described physical phenomena of convection in weld pool and heat transfer in workpiece during variable polarity vertical-up plasma Arc Welding Process. Boundary conditions for the developed governing equations were given. Welding energy input for variable polarity vertical-up plasma Arc Welding Process was quantitatively expressed. Free surface deformation of the keyhole molten pool was coupled into calculation. Effect of wire filling on the geometry of molten pool and weld reinforcement was considered in the simulation. Correlations of temperature and thermophysical properties for aluminum alloy 2219 were quantitatively established. A control volume based finite difference method was used to solve the discrete governing equations. Moreover, dynamic evolutions of geometrical profile, dimension and fluid flow for the molten pool and keyhole were simulated through the developed computational routines, which achieved transient solution of fluid flow field coupling with thermophysical properties, temperature field and weld pool free surface deformation. Besides, the effect of the workpiece thickness on the moments of keyhole formation and stable keyhole establishment was analyzed, and thermal cycles for the main Welding stage were calculated. In addition, experiments via variable polarity vertical-up plasma Arc Welding technique were conducted, and the established models were experimentally verified through weld cross-section profiles. © 2006 Elsevier B.V. All rights reserved.
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Numerical calculation of variable polarity keyhole plasma Arc Welding Process for aluminum alloys based on finite difference method
Computational Materials Science, 2007Co-Authors: H.-x. Wang, Y.-h. Wei, C.l. YangAbstract:Variable polarity keyhole plasma Arc Welding Process was simulated via the developed models in nonorthogonal body-fitted curvilinear coordinate system depicting the physical phenomena in the keyhole weld pool. Free surface shape of the keyhole weld pool, variable polarity Welding current, temperature-dependent material thermophysical properties, wire filling, and turbulent mixing in the molten metal were considered in the computation. Transient evolution of the geometry for the keyhole weld pool was predicted. Geometrical dimensions for the keyhole molten pool at different Welding conditions were computed. Effects of wire filling, enhanced fluid thermal conductivity also kinetic viscosity on geometry and velocity field for the keyhole weld pool were analyzed. Temperature distribution for the plasma Arc was calculated. In addition, the models used were experimentally validated through the geometry of the weld cross-section. © 2006 Elsevier B.V. All rights reserved.
Degala Venkata Kiran - One of the best experts on this subject based on the ideXlab platform.
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Analysis of molten pool behavior by flux-wall guided metal transfer in low-current submerged Arc Welding Process
International Journal of Heat and Mass Transfer, 2017Co-Authors: Degala Venkata Kiran, Suck-joo NaAbstract:Abstract A three-dimensional numerical heat transfer and fluid flow model is developed to understand the temperature distribution and molten pool behavior in a low-current submerged Arc Welding Process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, this paper suggests a flux wall boundary model to simulate flux-wall guided transfer for a single-wire low-current submerged-Arc Welding Process. This study simulates how porosity can be trapped in the V-groove joint with a flux-wall guided transfer. The computed weld width and fusion-zone shape are in fair agreement with the corresponding experimental results.
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Arc interaction and molten pool behavior in the three wire submerged Arc Welding Process
International Journal of Heat and Mass Transfer, 2015Co-Authors: Degala Venkata Kiran, Woohyun Song, Suck-joo NaAbstract:Abstract A three-dimensional numerical heat transfer and fluid flow model is developed to understand the temperature distribution and molten pool behavior in a three wire submerged Arc Welding Process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, a physical model is developed to estimate the Arc center displacement. For a given Welding condition, connecting the leading electrode with direct current electrode positive polarity, the middle and trailing electrodes with trapezoidal alternating current waveform displayed deeper weld pools when compared to the sine waveforms. Within the range of Welding conditions considered in the present work, weld width is significantly influenced by the leading Arc whereas the penetration by the middle and trailing Arcs. The computed weld width and penetration are in fair agreement with the corresponding experimental results.
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molten pool behavior in the tandem submerged Arc Welding Process
Journal of Materials Processing Technology, 2014Co-Authors: Daewon Cho, Degala Venkata Kiran, Woohyun Song, Suck-joo NaAbstract:Abstract A three-dimensional numerical heat transfer and fluid flow model is developed to examine the temperature profiles, velocity fields, weld pool shape and size in a two-wire tandem submerged Arc Welding Process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, a novel scheme is proposed to handle the Arc interaction and its influence on the molten droplet transfer direction. Using the computational fluid dynamics simulations, it is found that the droplet movement and Arc forces from the leading electrode heavily affect the molten pool flow patterns and the resultant bead shapes, even though the same heat inputs are applied. The computed weld width and penetration are in fair agreement with the corresponding experimental results.
W. Y. Lin - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear interval model control of quasi-keyhole Arc Welding Process
Automatica, 2004Co-Authors: W. Lu, Y.m. Zhang, W. Y. LinAbstract:This paper addresses the development of a nonlinear model based interval model control system for the quasi-keyhole Arc Welding Process, a novel Arc Welding Process which has advantages over the laser Welding Process and conventional Arc Welding Processes. The structure of the nonlinear model chosen was proposed based on an analysis of the quasi-keyhole Process to be controlled. Because of the variations in the manufacturing conditions, the parameters of the nonlinear model are uncertain but bounded by fixed intervals if the range of the manufacturing conditions is specified. To determine the intervals, extreme operating conditions/parameters (manufacturing conditions) were used to conduct experiments. Each experiment gives a set of model parameters and the interval for each parameter is given by the minimum and maximum among the values obtained from different experiments. Closed-loop control experiments have verified the effectiveness of the developed system as a robust control which requires no re-adjustment and can function properly when fluctuations/variations in manufacturing conditions, and thus the Process dynamics, change, vary, or fluctuate. © 2003 Elsevier Ltd. All rights reserved.
