scholarly journals Influence of Inclination of Welding Torch on Weld Bead during Pulsed-GMAW Process

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2652
Author(s):  
Ping Yao ◽  
Heqing Tang ◽  
Kang Zhou ◽  
Hongyan Lin ◽  
Zihui Xu ◽  
...  
Keyword(s):  
Curve Fitting ◽  
Mean Squared Error ◽  
Gas Metal Arc Welding ◽  
Weld Bead ◽  
Operation Condition ◽  
Bead Width ◽  
Metal Arc Welding ◽  
Welding Torch ◽  
Inclination Angles ◽  
Geometry Characteristic

This work is about the influence rule of inclination of welding torch on the formation and characteristics of weld bead during the pulsed-gas metal arc welding (GMAW) process based on the robotic operation. The inclination of welding torch was an important operation condition during the pulsed-GMAW process, because it can affect the formation and quality of weld bead, which was the output of the process. In this work, the different inclination modes and values were employed to conduct actual welding experiments, and some influence rules can be obtained according to examine the surface topography and cross section. Then, to obtain further rules, serious measurements for the geometry characteristic parameters were conducted and corresponding curve fitting equations between inclination angles and the bead width, penetration and bead height were obtained, and the largest error of these curve fitting equations was 0.117 mm, whose corresponding mean squared error (MSE) was 0.0103. Corresponding verification experiments validated the effectiveness of the curve fittings and showed the second order polynomials were proper, and the largest errors between measurements and curve fitting equations for inclination angle under backward mode were larger than those under forward mode, and were 0.10 mm and 0.15 mm, respectively, which corresponded to the penetration and were below 10%, therefore the equations can be used to predict the geometry of the weld bead. This work can benefit the process and operation optimization of the pulsed-GMAW process, both in the academic researches and actual industrial production.

Dynamic Modeling and Adaptive Control of the Gas Metal Arc Welding Process

1994 ◽  
Vol 116 (3) ◽  
pp. 405-413 ◽  
Author(s):  
Jae-Bok Song ◽  
David E. Hardt
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Adaptive Control System ◽  
Bead Width ◽  
Metal Arc Welding ◽  
Arc Welding Process

Control of the welding process is a very important step in welding automation. Since the welding process is complex and highly nonlinear, it is very difficult to accurately model the process for real-time control. In this research, a discrete-time transfer function matrix model for gas metal arc welding process is proposed. This empirical model takes the common dynamics for each output and inherent process and measurement delays into account. Although this linearized model is valid only around the operating point of interest, the adaptation mechanism employed in the control system render this model useful over a wide operating range. Since welding is inherently a nonlinear and multi-input, multi-output process, a multivariable adaptive control system is used for high performance. The process outputs considered are weld bead width and depth, and the process inputs are chosen as the travel speed of the torch and the heat input. A one-step-ahead (or deadbeat) adaptive control algorithm combined with a recursive least-squares methods for on-line parameter estimation is implemented in order to achieve the desired weld bead geometries. Control weighting factors are used to maintain the stability and reduce excessive control effort. Some guidelines for the control design are also suggested. Command following and disturbance rejection properties of the adaptive control system for both SISO and MIMO cases are investigated by simulation and experiment. Although a truly independent control of the outputs is difficult to implement because of a strong output coupling inherent in the process, a control system for simultaneous control of bead width and depth was successfully implemented.

Modeling of weld bead geometry for rapid manufacturing by robotic GMAW

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540033 ◽  
Author(s):  
Tao Yang ◽  
Jun Xiong ◽  
Hui Chen ◽  
Yong Chen
Keyword(s):  
Gas Metal Arc Welding ◽  
Dimensional Accuracy ◽  
Great Accuracy ◽  
Weld Bead ◽  
Bead Geometry ◽  
Weld Bead Geometry ◽  
Bead Width ◽  
Metal Arc Welding ◽  
Bead Height ◽  
Metallic Parts

Weld-based rapid prototyping (RP) has shown great promises for fabricating 3D complex parts. During the layered deposition of forming metallic parts with robotic gas metal arc welding, the geometry of a single weld bead has an important influence on surface finish quality, layer thickness and dimensional accuracy of the deposited layer. In order to obtain accurate, predictable and controllable bead geometry, it is essential to understand the relationships between the process variables with the bead geometry (bead width, bead height and ratio of bead width to bead height). This paper highlights an experimental study carried out to develop mathematical models to predict deposited bead geometry through the quadratic general rotary unitized design. The adequacy and significance of the models were verified via the analysis of variance. Complicated cause–effect relationships between the process parameters and the bead geometry were revealed. Results show that the developed models can be applied to predict the desired bead geometry with great accuracy in layered deposition with accordance to the slicing process of RP.

A Study of Software Approach for Predicting Weld Bead Geometry in Shielded Metal Arc Welding (SMAW) Process

2014 ◽  
Vol 554 ◽  
pp. 386-390
Author(s):  
C.W. Mohd Noor ◽  
Manuhutu Ferry ◽  
W.B. Wan Nik
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Bead Geometry ◽  
Shielded Metal Arc Welding ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
Bead Width ◽  
Real Process ◽  
Metal Arc Welding

The prediction of the optimal weld bead width is an important aspect in shielded metal arc welding (SMAW) process as it is related to the strength of the weld. This paper focuses on investigation of the development of the simple and accurate model for prediction of weld bead geometry. The experiment used welding current, arc length, welding speed, welding gap and electrode diameter as input parameters. While output parameters are bead width, depth of penetration and weld reinforcement. A number of 33 mild steel plate specimens had undergone the SMAW welding process. The experimental data was used to develop mathematical models using SPSS software. The actual and predicted values of the weld bead geometry are compared. The proposed models shows positive correlation to the real process.

Study the Shielding Gas Effect on the Metal Transfer and Weld Pool Dynamics in GMAW

2009 ◽  
Author(s):  
Z. H. Rao ◽  
J. Hu ◽  
S. M. Liao ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Gas Metal Arc Welding ◽  
Droplet Formation ◽  
Shielding Gas ◽  
Bead Width ◽  
Droplet Shape ◽  
Helium Content ◽  
Mixing Ratios ◽  
Metal Arc Welding ◽  
Dependent Processes

This paper studied the influences of shielding gas compositions on the transport phenomena in the metal domain during gas metal arc welding (GMAW). A comprehensive model was developed to simulate the time-dependent processes of the electrode melting; the droplet formation, detachment, transfer and impingement onto the workpiece; the weld pool dynamics and bead formation and their transient coupling with the arc plasma. The transient melt-flow velocity and temperature distributions in the metal shielded by pure argon and argon-helium mixtures with various mixing ratios are presented. It is predicted that the increase of helium content and the resulting arc contraction induce an upward electromagnetic force at the bottom of the droplet to sustain the droplet at the electrode tip. As a result, the more oblate droplet and the longer droplet formation time are produced. The behaviors of the predicted droplet shape and detachment frequency are in agreement with the published results. It is also found that, under the identical energy input, the weld bead has a shallower penetration depth and broader bead width when helium content increases.

scholarly journals Development of a Multidirectional Wire Arc Additive Manufacturing (WAAM) Process with Pure Object Manipulation: Process Introduction and First Prototypes

2021 ◽  
Vol 5 (4) ◽  
pp. 134
Author(s):  
Khushal Parmar ◽  
Lukas Oster ◽  
Samuel Mann ◽  
Rahul Sharma ◽  
Uwe Reisgen ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Gas Metal Arc Welding ◽  
Operating Conditions ◽  
Metal Arc Welding ◽  
Welding Torch ◽  
Building Process ◽  
Single Bead ◽  
Software Interfaces ◽  
Substrate Plate ◽  
Wire Arc Additive Manufacturing

Wire Arc Additive Manufacturing (WAAM) with eccentric wire feed requires defined operating conditions due to the possibility of varying shapes of the deposited and solidified material depending on the welding torch orientation. In consequence, the produced component can contain significant errors because single bead geometrical errors are cumulatively added to the next layer during a building process. In order to minimise such inaccuracies caused by torch manipulation, this article illustrates the concept and testing of object-manipulated WAAM by incorporating robotic and welding technologies. As the first step towards this target, robotic hardware and software interfaces were developed to control the robot. Alongside, a fixture for holding the substrate plate was designed and fabricated. After establishing the robotic setup, in order to complete the whole WAAM process setup, a Gas Metal Arc Welding (GMAW) process was built and integrated into the system. Later, an experimental plan was prepared to perform single and multilayer welding experiments as well as for different trajectories. According to this plan, several welding experiments were performed to decide the parametric working range for the further WAAM experiments. In the end, the results of the first multilayer depositions over intricate trajectories are shown. Further performance and quality optimization strategies are also discussed at the end of this article.

The Effect of Shielding Gas and Arc Voltage on the Bead Shape and Pore Generation of Galvanized Steel Pipe Welds with Gas Metal Arc Welding

2013 ◽  
Vol 746 ◽  
pp. 240-244
Author(s):  
Young Min Lim ◽  
Bok Su Jang ◽  
Jin Hyun Koh
Keyword(s):  
Surface Tension ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
High Surface ◽  
Welding Process ◽  
Galvanized Steel ◽  
Steel Pipe ◽  
Bead Width ◽  
Arc Voltage ◽  
Metal Arc Welding

The present study was carried out to investigate the effect of shielding gases (Ar, CO2, Ar+5%CO2, Ar+10%CO2, Ar+20%CO2, Ar+2%O2, Ar+5%O2 and Ar+10%O2) and arc voltage (16-24V) on the bead shape and porosity formation of galvanized steel pipe welds made by a gas metal arc welding process. It was confirmed that the bead height was lowered and bead width was wider with increasing voltages. Bead shapes made by Ar was narrow and convex due to a high surface tension while those made by mixture gas compositions such as Ar+CO2 and Ar+O2t became wider and smoother due to a lower surface tension. The pores were generated the least at low arc voltages of 16-20V and they were more formed over 22V. It was confirmed that Ar produced the most porosity while active and mixture gases such as CO2 and Ar+10%CO2 , Ar+5%O2 and Ar+10%O2 produced little pores by forming ZnO in the weld pool.

A Study on the Weld Bead Characteristics in Pulsed Gas Metal Arc Welding With Rotating Arc

2004 ◽  
Author(s):  
P. Srinivasa Rao ◽  
O. P. Gupta ◽  
S. S. N. Murty
Keyword(s):  
Arc Welding ◽  
Gma Welding ◽  
Gas Metal Arc Welding ◽  
Bead Geometry ◽  
High Productivity ◽  
Metal Arc Welding ◽  
Welding Torch ◽  
Welding Steel ◽  
Rotating Arc ◽  
Selection Of

Pulsed Gas Metal Arc Welding is widely used in industries because of its high productivity. The bead geometry obtained in welding steel is far from ideal and needs to be improved. It is experimentally observed that the beads are either convex or the penetration is deep and narrow. Both these conditions are undesirable. Proper selection of pulse parameters can improve the wetting, but the penetration remains finger type penetration. An arc rotation mechanism is developed which can be adapted to any conventional GMA welding torch. The beads deposited with rotating arc are flat and the penetration is semi-circular. It is observed that the penetration is maximum only at a particular rotating arc speed.

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