Torch Angle Research Articles

Analysis on mechanical and metallurgical characterisation of FBTIG weldments using 15CDV6 steel

The minimum and maximum level in welding current, speed, flow rate, torch angle and arc gap of the GTAW process is done by conducting real-time experiments. Then with the outcomes of the experiment, the further work is carried under DOE, and it includes the necessary optimisation concept. This research continues with the NN-based GWO for modelling the welding parameters. This research work presents the PFTIG and FBTIG welding with the help of optimum nano powder and optimum flux gap. Next stage of research is fabrication and it is done in square butt joint by utilising the both optimum parameters. Moreover, in the PWHT condition, both the mechanical and metallurgical characterisation of FBTIG weldments takes place in this paper and the strength of the fabricated butt joint is found by LSP, as it is due to the failure in the weld zone. Finally, a comparison is carried out between PWHT and the PWHT + LSP conditions in terms of mechanical properties and the residual stress measurements.

Analysis on mechanical and metallurgical characterisation of FBTIG weldments using 15CDV6 steel

The minimum and maximum level in welding current, speed, flow rate, torch angle and arc gap of the GTAW process is done by conducting real-time experiments. Then with the outcomes of the experiment, the further work is carried under DOE, and it includes the necessary optimisation concept. This research continues with the NN-based GWO for modelling the welding parameters. This research work presents the PFTIG and FBTIG welding with the help of optimum nano powder and optimum flux gap. Next stage of research is fabrication and it is done in square butt joint by utilising the both optimum parameters. Moreover, in the PWHT condition, both the mechanical and metallurgical characterisation of FBTIG weldments takes place in this paper and the strength of the fabricated butt joint is found by LSP, as it is due to the failure in the weld zone. Finally, a comparison is carried out between PWHT and the PWHT + LSP conditions in terms of mechanical properties and the residual stress measurements.

Digitalized Evaluation of Welder Skill by using Cyclogram Characteristics

This paper proposes a new evaluation method for welder skill in Gas Metal Arc Welding (GMAW) process in term of studying the natural hand-movement that affect the signal processing. Weld quality of GMAW generally depends on welder skill to maintain the uniform of hand movement. Therefore, the welder skill is considered as the critical point to maintain the weld quality. Hence, welding current and voltage signal could be an alternative way for monitoring and assessing the skill of welder based on the signal variation of the welding process. This research defines in two stages, first is the physical-simulation using robot welding Fanuc Arc Mate 100iB and monitoring the signal using Cyclogram technique. Second is comparing the Cyclogram characteristic of robot welding and manual welder. By using the data acquired, the characteristic of Cyclogram was analyzed by varying Torch angle change (W1) and Torch-height change (W2) to investigate the signal processing. Furthermore, the data of current and voltage were generated as a quantitative method to determine the size of Cyclogram. The results show that the method capable of differentiating the two beginner welders compare to the robot welding performance based area of Cyclogram characteristic. Finally, the Cyclogram could be a novel tool for monitoring and evaluating the welder skill with high sensitivity to detect hand motion.

Effect of relative position in low-power pulsed-laser–tungsten-inert-gas hybrid welding on laser-arc interaction

In laser-arc hybrid welding, the appropriate position between the laser beam and arc will be helpful in forming an intensive interaction and significantly increasing penetration depth. In this paper, first, an orthogonal experiment with three factors and four levels were carried out on the inclination angle of the welding torch, the arc length, and the distance between laser beam and TIG electrode, Dla, to find the optimal positional parameters with the strongest laser-arc interaction. The composite plasma behaviors and interaction mechanism between laser and arc were then analyzed under different position parameters; on this basis, the influence of laser power on the laser-arc interaction was further analyzed. Results reveal that the interaction is a decided difference under different positions. When the distance Dla is small, the arc will be significantly compressed; when the laser acts on the arc center, the pre-heating of the arc will greatly improve the laser absorption rate, a shorter arc length will help to further increase the penetration. When the distance Dla, the arc length, and the welding torch angle are 1.5, 1 mm, and 45°, respectively, the laser-arc interaction reaches its strongest level and the weld penetration is the deepest. In this case, the arc tail is obviously shortened, and the laser-arc composite plasma volume in the central region is greatly increased. Further, when the laser-power percentage is 10%–50%, the weld profile shows the characteristics of laser heat-conduction welding; when the laser-power percentage is 50%–80%, the weld profile shows the characteristics of laser deep penetration welding; and when the laser-power percentage is 80%–100%, the valid penetration is shallow and accompanied by a large splash due to the very short laser duration. But the weld profile should also be characterized by typical laser deep-penetration welding when the duration of laser action is enough long.

Optimizing parameters of TIG welding process using grey wolf optimization concerning 15CDV6 steel

Welding is a fabrication process that joins materials by causing fusion. Even though there available various welding types like MIG/MAG and MMA welding, they need additional electrodes while doing welding process. Aspiration of this paper is to introduce Tungsten Inert Gas (TIG) welding via an optimization approach namely Grey Wolf Optimization (GWO) that is systemized for high-quality welding process and with this aspect, it discovers the impact of TIG welding process parameters on the weld bead profile of 15CDV6 High Strength Low Alloy (HSLA) steel. Furthermore, the used GWO algorithm effectively recognizes the optimal welding constraints for increasing the Depth of Penetration (DOP) and reduces Bead Width (BW) as well as Heat-Affected Zone (HAZ) width as well. The cooperating variables for model investigation are Welding current (WEc), Torch speed (TOs), Gas flow rate (GAR), Torch angle (TOG) and Arc gap (ARG). The investigation is processed undertaking certain responding factors like DOP, BW and HAZ width. The supplementary factor of the proposed model shows its beneficial work through of 15CDV6 steel in progressing rocket-motor hardware program, engineering works in industrial level, pressure vessel fabrication and so on. The attained outcomes have demonstrated its extreme level of benefits in some of the strategies, which utilizing 15CDV6 steel in rocket-motor hardware program, industries, pressure vessels fabrication and so on.

Three-Dimensional Numerical Analysis of Weld Pool in GMAW with Fillet Joint

GMA welding is widely used in many different fields such as automotive, shipbuilding and plant industry and its demand is growing day by day because of its high productivity and quality with cost reduction in manufacturing process. Nevertheless, the studies have been reported just a few cases so far due to its difficulties in expressions for the complexity of physical phenomena and in the derivation of the mathematical models. In this research, its complex numerical models including three-dimensional heat flux, arc pressure and electromagnetic force are newly suggested and its validation is proved through the comparison between the experimental and simulation results. Basically, the arc heat flux, arc pressure and Marangoni flow are employed as the boundary conditions. And electromagnetic force and buoyancy are realized as body terms. The governing equations such as the continuity, momentum, VOF and energy equations are adopted as usual simulations. It is, however, that only these equations cannot fulfill all requirements to investigate the behavior of the weld pool in GMA welding. To compensate the insufficient, three-dimensional mathematical model and coordinate transform of arc are newly suggested to reflect the twisted torch angle and arc effective radius change according to the distance from electrode tip. Suggested analysis model is verified through comparison to lap joint fillet GMAW experiment of steel sheets for automotive industry and it shows successful correspondence.

ENENTUAN PARAMETER PENGELASAN RANGKA UTAMA SEPEDA MOTOR MATIC BAGIAN DEPAN MENGGUNAKAN LAS MIG OTOMATIS (PANASONIC TM-1400G3)

Abstract: Main frame welding at the front automatic motorcycle of PT. XXX is the stage of (trial production). The welding machine is Panasonic TM-1400G3 MIG automatic welding machine with 75% Argon and 25% Ar-CO2. Main frame material low carbon steel STAM 390G. To obtain the welding results in accordance with the standards specified by the client, weld testing parameters are varied for each test, which are ampere and voltage. The constant welding parameters in this research are travel speed, gas flow, welding direction, tip distance to workpiece, torch angle and welding angle. All test results are inspected visually and dimensionally, if passed, it will be followed by inspection of macro structure analysis. The results measured on the macro structure analysis ar : penetration (a1), penetration (a2), bead welding, throuth, leg length and crown with standard measurement values determined by the client PT.XXX. The welding results (OK) in the macro structure analysis measurement are defined as reference parameters for mass production. The best parameters for main frame welding are vertical position down (3G) with 170 Ampere current and 20 Volt voltages, and for horizontal position (2G) with 180 ampere current parameters and 17 Volt voltages.

Optimization of FCAW Parameters for Ferrite Content in 2205 DSS Welds Based on the Taguchi Design Method

This study presents the Taguchi design method with L9 orthogonal array which was carried out to optimize the flux‐cored arc welding (FCAW) process parameters such as welding current, welding voltage, welding speed, and torch angle with reference to vertical for the ferrite content of duplex stainless steel (DSS, UNS S32205) welds. The analysis of variance (ANOVA) was applied, and a mathematical model was developed to predict the effect of process parameters on the responses. The results indicate that welding current, welding voltage, welding speed, torch angle with reference to vertical, and the interaction of welding voltage and welding speed are the significant model terms connected with the ferrite content. The ferrite content increases with the increase of welding speed and torch angle with reference to vertical, but decreases with the increase of welding current and welding voltage. Through the developed mathematical model, the target of 50% ferrite content in weld metal can be obtained when all the welding parameters are set at the optimum values. Finally, in order to validate experimental results, confirmation tests were implemented at optimum working conditions. Under these conditions, there was good accordance between the predicted and the experimental results for the ferrite content.

Analysis of Shielded metal arc welding parameter on Depth of Penetration on AISI 1020 plates using Response surface methodology

This paper concentrates on the analysis of shielded metal arc welding parameter to maximize the depth of penetration using response surface methodology. Welding current, polarity of electrode and torch angle were taken as input parameter. Design of Experiment was accomplanished by full factorial method RSM based model has been developed to determine the depth of penetration attained by various welding parameter. The quadratic model developed using RsM shows high accuracy and canbe used for predicting within limit of factor investigated.

Effect of Heat Source Positioning on Hybrid TIG-MAG Arc Welding Process

Hybrid TIG-MAG Arc Welding implies the two conventional arc welding processes combine to provide a more improved outcome overcoming their limitations at the individual level. The hybridization demands the favorable interaction of the participating heat sources to produce an effective coalescence. The participating heat sources interact in harmony when positioned optimally to enter each other’s domain of influence in the synergistic manner. This study is an attempt to investigate the effect of positioning of heat sources on the hybrid arc welding process in terms of the achieved weld penetration for the bead on plate welding of mild steel. The study presents special welding torch geometries for easy location and clamping on an indigenous fixture which forms an automated assembly to carry out the devised hybrid arc welding process. The study identifies torch angles, arc lengths and the arc separation as the 5 parameters critical in positioning of the heat sources. Torch angles have been optimized through a 2-stage preset experimentation. The arc lengths and the arc separation have been optimized considering 4th order parameter interactions in a quadratic through a designed experiment by analyzing the generated response surfaces and the parameter interaction profile.

Modeling of an artificial intelligence system to predict structural integrity in robotic GMAW of UHSS fillet welded joints

The use of welded lightweight steels in structural applications is increasing due to the greater design possibilities offered by such materials and the lower costs compared to conventional steels. Ultra-high-strength steels (UHSS) having tensile strength of up to 1700 MPa with a high strength-to-weight ratio offer a unique combination of qualities for diverse industrial applications. For productivity and quality reasons, gas metal arc welding (GMAW) is usually utilized for welding of UHSS. However, for full penetration fillet welded joints, the need for high heat input to gain acceptable weld penetration is problematic when welding UHSS. This is due to UHSS sensitivity to heat input and possible heat-affected zone (HAZ) softening. In this paper, an attempt is made, on the basis of analysis of experimental reviews, to identify and define relationships between nonlinear weldability factors to enable creation of an artificial intelligence model to predict full penetration in robotic GMAW fillet welded joints of UHSS S960QC. Welding variables and parameters associated with GMAW are first evaluated by reviewing scientific literature. The possibility of employing an artificial neural network (ANN) to predict full penetration fillet weld characteristics is then examined. It is noted that nonlinear variables associated with the GMAW process, such as heat input, contact tip to work distance (CTWD), and torch angle, and their related parameters, which pose weldability challenges, can be modeled by applying artificial intelligence systems. Ensuring full penetration in fillet welded joints of UHSS using artificial intelligence is thus feasible. Further, an optimized control system could potentially be developed by incorporating adaptive robotic GMAW with an artificial intelligence-based system to guarantee sound structural integrity that conforms to EN ISO 5817. The paper increases awareness of welding aspects of UHSS S960QC and presents an approach for overcoming existing limits to GMAW via adaptive robotic welding and artificial intelligence systems.

A Finite Element Model to Investigate the Impact of Torch Angle on an Autogenous TIG Welding Process

A numerical modelling activity was completed to explore the impact that the angle θ created by the torch from the vertical had upon the thermal and mechanical predictions for a T-joint autogenous TIG welded component. A parametric system of 9 models was set-up to simulate the effects of varying the angle θ by a small, potentially unnoticeable amount to a manual operator. The variations ranged from -8° to +8° away from a nominal default position of torch. The numerical models were created and computed using specialist welding simulation software Sysweld, and pre/post-processing software Visual Environment (both owned by ESI Group). The resulting weakly-coupled thermal and mechanical analyses illustrated a small deflection of angle that the weld bead was penetrating in to the T-joint, consistent with the variation in torch angle, and a negligible variation in peak temperature of 1.8%. The mechanical results however demonstrated a more significant output, namely that the distortion observed upon the vertical plate within the T-joint was predicted to increase by over 50% as result of this small shift in the welding torch angle. However, other mechanical predictions for plastic strain, Von Mises residual stress and distortion on the horizontal plate, were all suggesting only very minor sensitivity (typically less than 5%) to the torch angle variation. However, the predictions for vertical plate distortions demonstrate how difficult a manual TIG operation can be to perform with sufficient process control and repeatability, due to the significant impact that human operator-induced variation has upon some of the mechanical outputs.

Recurrent neural networks to model input-output relationships of metal inert gas (MIG) welding process

The mechanical strength of weld-bead is dependent on its geometric parameters like bead height, width and penetration, which depend on input process parameters, namely welding speed, arc voltage, wire feed rate, gas flow rate, nozzle-to-plate distance, torch angle etc. Recurrent neural networks were used for conducting both forward and reverse mappings using three approaches. The first approach dealt with the training of Elman network through updating its connecting weights using a back-propagation algorithm. In second approach, a real-coded genetic algorithm was used along with the back-propagation algorithm to tune the network. The third approach utilised a real-coded genetic algorithm only to optimise the network. In forward mapping, third approach was found to outperform the others, but in reverse mapping, first and second approaches were seen to perform better than the third one. The performances of these approaches were found to be data dependent.

Recurrent neural networks to model input-output relationships of metal inert gas (MIG) welding process

The mechanical strength of weld-bead is dependent on its geometric parameters like bead height, width and penetration, which depend on input process parameters, namely welding speed, arc voltage, wire feed rate, gas flow rate, nozzle-to-plate distance, torch angle etc. Recurrent neural networks were used for conducting both forward and reverse mappings using three approaches. The first approach dealt with the training of Elman network through updating its connecting weights using a back-propagation algorithm. In second approach, a real-coded genetic algorithm was used along with the back-propagation algorithm to tune the network. The third approach utilised a real-coded genetic algorithm only to optimise the network. In forward mapping, third approach was found to outperform the others, but in reverse mapping, first and second approaches were seen to perform better than the third one. The performances of these approaches were found to be data dependent.

Prediction of Welded Joint Strength in Plasma Arc Welding: A Comparative Study Using Back-Propagation and Radial Basis Neural Networks

Welding input parameters such as current, gas flow rate and torch angle play a significant role in determination of qualitative mechanical properties of weld joint. Traditionally, it is necessary to determine the weld input parameters for every new welded product to obtain a quality weld joint which is time consuming. In the present work, the effect of plasma arc welding parameters on mild steel was studied using a neural network approach. To obtain a response equation that governs the input-output relationships, conventional regression analysis was also performed. The experimental data was constructed based on Taguchi design and the training data required for neural networks were randomly generated, by varying the input variables within their respective ranges. The responses were calculated for each combination of input variables by using the response equations obtained through the conventional regression analysis. The performances in Levenberg-Marquardt back propagation neural network and radial basis neural network (RBNN) were compared on various randomly generated test cases, which are different from the training cases. From the results, it is interesting to note that for the above said test cases RBNN analysis gave improved training results compared to that of feed forward back propagation neural network analysis. Also, RBNN analysis proved a pattern of increasing performance as the data points moved away from the initial input values.

Study and Fabrication of Virtual TIG Welding Equipment

The green technology is applied in training welders by using simulation equipment. The virtual tungsten inert gas welding (TIG welding) equipment permits of reducing the cost of welding practice training by saving on materials, electricity. It does not cause the environmental pollution. It is not harmful to welding learners. This paper studies on the permissible range of technological and technical parameters of TIG welding process. This is basis to develop the software in order to evaluate learners on virtual TIG welding equipment. These are foundations to manufacture the virtual TIG welding equipment. This equipment allows welding learners to practice the basic operations and skills as on real TIG welding machine, including the techniques of striking the arc, restarting the arc, maintenance of arc length, controlling of torch angle, filler rod angle, the operations of torch move, filler rod move,... with different welds and different positions

Relationship between penetration and porosity in horizontal fillet welding by a new process “hybrid tandem MAG welding process”

In the shipbuilding and bridge construction industries, shop primer paint is coated to the surface of steel plates in order to protect them from rusting during a long fabrication period. However, when arc welding is applied to the primer-coated plates, the arc heat may decompose and vaporize the coating. Then, the generated gas will be enclosed in the weld metal during the solidification process, causing the porosity defects, such as blowholes and the pits. In this study, the effects of penetration depth and non-penetrated joint root length on the generation of blowholes were clarified with various welding parameters. A new horizontal fillet welding process called ‘hybrid tandem MAG (HTM)’ was developed, a combination of a solid wire for the leading electrode and a flux-cored wire for the trailing electrode. The process features deep penetration and excellent porosity resistance. In order to reduce porosity in the fillet welding of primer-coated steel plate, it was found that the following measures are effective: (a) increasing the penetration depth and (b) decreasing the non-penetrated joint root length. The reduction of porosity by increasing the penetration depth is achieved by the formation of consistent ejection passage for vaporized gas. The phenomena mentioned above were verified by observing the interior of the weld pool directly by using an X-ray video camera. It is effective to reduce the leading electrode torch angle and to use a combination of high current and low voltage to create a buried arc to realize these measures. The MAG (HTM) procedure reduced the porosity formation to one tenth of that produced with the conventional tandem MAG process even at travel speeds up to 1600 mm/min.

Influência dos Níveis das Correntes, Ângulo de Inclinação da Tocha e Distância entre a Tocha e a Peça sobre a Geometria do Cordão de Solda Usando “Plasma-MIG” com Arcos Concêntricos

Resumo Um adequado controle da poça fundida é de fundamental importância para obtenção de soldas em conformidade geométrica com as especificações de projeto. O processo “Plasma-MIG” com Arcos Concêntricos tem sido apresentado como uma alternativa inovadora neste sentido. Desta forma, este trabalho objetivou ampliar os estudos relacionados ao balanço das correntes entre o eletrodo consumível e o arco externo, ao ângulo de inclinação da tocha e à distância entre a tocha e a peça sobre a performance do processo. Soldagens de simples deposição sobre chapa foram executadas na posição plana, visando identificar individualmente o efeito de cada das variáveis sobre a geometria do cordão. A corrente no arco externo foi avaliada em quatro níveis e os efeitos dos demais parâmetros foram avaliados em três níveis. Foi observado que incrementos na corrente do arco externo favorece o aumento da largura, penetração e área fundida e redução do reforço. O aumento da distância da tocha até a peça fez o reforço aumentar e as larguras, penetração e área fundida diminuíram. Quanto ao ângulo de ataque da tocha, a largura e área fundida aumentaram e o reforço e penetração diminuíram quando se muda do modo puxando para empurrando.

Optimization of GMAW Parameters to Improve the Mechanical Properties

In this paper, multi objective optimization of Gas Metal Arc Welding GMAW) parameters are carried out to yield good mechanical strength in welded joints. Most of the failures are occurred on the welded elements due to the setting of improper welding parameters. The strength of welded joints in GMAW depends on several input process parameters such as welding current, welding voltage, gas flow rate, torch angle, welding speed, wire size and electrode feed rate. Wrong selection of these process parameters will lead to bad quality welds. So there is a need to control the process parameters to obtain good quality welded joints. For getting the better values of these parameters, it needs to conduct experiments by varying the input process parameters that are affecting the strength of the welded joints. In this work nine experimental runs based on an L9 orthogonal array of Taguchi method are performed to optimize the strength of the welded joint. To achieve this Grey Relational Analysis (GRA) is used. In this work Aluminum6063 material is used as base material.

Effect of torch position and angle on welding quality and welding process stability in Pulse on Pulse MIG welding–brazing of aluminum alloy to stainless steel

In this paper, Pulse on Pulse metal inert gas (MIG) welding–brazing of 6061 aluminum alloy to 304 stainless steel in a lap configuration was developed to investigate the effect of torch position and angle on the welding quality and welding process stability. Images of arc, electrical signals of welding current, and welding voltage were acquired in synchronous modes by a high-speed camera and electrical signal acquisition system, respectively. The obtained results demonstrate that arc shape, macrostructure, microstructure, and mechanical properties are sensitive to torch aiming position when torch travel angle is 20° and work angle is 0°. However, when travel angle is 20° and work angle is 20°, the effect of torch aiming position is insignificant. It is easier to strike arc and maintain it on the surface of aluminum alloy compared to stainless steel. High-strength joints, whose fracture occurred at heat-affected zones of Al alloys at 89 MPa up to 72 % of the tensile strength of Al alloys, have been obtained. Moreover, a comprehensive evaluation method for the welding process stability based on statistical techniques has been proposed. This method can be easily and quickly integrated in real-time control of the welding process, which provides a quantitative guidance in MIG welding–brazing of aluminum alloy to stainless steel.