Experimental Study and Modeling of GTA Welding Process

2003 ◽  
Vol 125 (4) ◽  
pp. 801-808 ◽  
Author(s):  
Min Jou
Keyword(s):  
Experimental Study ◽  
Weld Pool ◽  
Welding Speed ◽  
Welding Current ◽  
Distribution Parameter ◽  
Welding Parameters ◽  
Heat Distribution ◽  
Arc Length ◽  
Experimental Calibration ◽  
Current Voltage

It has been well recognized that the geometry of weld pool plays a fundamental role in determining the mechanical properties of weld joints. In this research, a series of experiment has been conducted to investigate the interaction and correlation of welding current, voltage, welding speed, and arc length affecting the formation of weld pool. The effect of arc length on arc efficiency and heat distribution parameter are also examined and addressed in this paper. In addition to the experimental study, a three-dimensional finite element model has been developed to analyze transient heat flow and to predict the formation of the weld pool. The correlation among the parameters including welding current, voltage, welding speed, arc length, open-loop response and the characteristic geometry of weld pool are established. The 3-D FEM can calculate not only the transient thermal histories but also the sizes of weld pool in single-pass arc welding. In order to obtain quality welds, this model will determine the effect of arc length on the formation of weld. Furthermore, the effects of welding parameters on the Gaussian heat source parameters (arc efficiency and heat distribution parameter) are also studied. The experimental calibration and verification are carried out to verify the numerical model. Experimental data are consistent and in quantitative agreement with values from FEM simulations.

Role of Welding Parameters in Determining the Geometrical Appearance of Weld Pool

1996 ◽  
Vol 118 (4) ◽  
pp. 589-596 ◽  
Author(s):  
R. Kovacevic ◽  
Z. N. Cao ◽  
Y. M. Zhang
Keyword(s):  
Fluid Flow ◽  
Weld Pool ◽  
Numerical Models ◽  
Three Dimensional ◽  
Welding Current ◽  
Gta Welding ◽  
Welding Parameters ◽  
Geometrical Shape ◽  
Arc Length ◽  
Weld Pools

A three-dimensional numerical model is developed to describe the fluid flow and heat transfer in weld pools. Both full penetration and free deformation of the top and bottom weld pool surfaces are considered. Temperature distribution and fluid flow field are obtained. In order to analyze the influence of welding parameters on the geometrical appearance of weld pools, a normalized model is developed to characterize the geometrical appearance of weld pools. It is found that welding current can significantly affect the geometrical shape. When welding current increases, the curvature of the pool boundary at the trailing end increases. The effect of the welding speed on the geometrical appearance is slight, although its influence on the pool size is great. In the interest range of arc length (from 1 mm to 4 mm), the arc length can affect both the size and the shape of the weld pool. However, compared with the welding current and speed, its influences are much weaker. GTA welding experiments are performed to verify the validity of the numerical models. The appearance of weld pools was obtained by using machine vision and a high-shutter speed camera. It is found that the calculated results have a good agreement with the experimental ones.

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

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Tianqi Li ◽  
Yingying Zhang ◽  
Lei Gao ◽  
Yunhao Zhang
Keyword(s):  
Mathematical Model ◽  
Process Parameters ◽  
Welding Speed ◽  
Design Method ◽  
Welding Current ◽  
Taguchi Design ◽  
Experimental Results ◽  
Ferrite Content ◽  
Welding Parameters ◽  
Torch Angle

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.

Research on the Technology for DC CMT Welding of AZ31B Magnesium Alloy

2013 ◽  
Vol 483 ◽  
pp. 18-22
Author(s):  
Rui Ying Zhang ◽  
Yun Yan Hu ◽  
Jun Wang
Keyword(s):  
Magnesium Alloy ◽  
Welding Speed ◽  
Orthogonal Experiment ◽  
Testing Machine ◽  
Weld Zone ◽  
Welding Current ◽  
Alloy Sheet ◽  
Arc Length ◽  
Az31b Magnesium Alloy ◽  
Cmt Welding

Orthogonal experiment method was used on DC CMT welding of AZ31B magnesium alloy sheet. The tensile test was carried out on the CMT5305 microcomputer control universal testing machine .The effect regular of welding current, arc length correction and welding speed on tensile strength and elongation was analyzed and acquired the optimal combination of process parameters. That is, welding current is 62A, arc length correction is +30% and welding speed is 50cm/min. The microhardness test on joints was carried out. Its found that the curve of microhardness is "W" shaped and the micro-hardness of HAZ is minimum and that of weld zone is maximum.

Influence of Gas Tungsten Arc Welding Parameters on the High-Temperature Erosion-Corrosion Resistance of Incoloy 800 Cladded by Stellite 12 for the Application as Thermowell

2011 ◽  
Vol 696 ◽  
pp. 248-253
Author(s):  
P. Promdirek ◽  
Somrerk Chandra-ambhorn ◽  
R. Prasong ◽  
S. Rittirat ◽  
N. Pornpaisansakul
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Flow Rate ◽  
Welding Speed ◽  
Erosion Rate ◽  
Welding Current ◽  
Welding Parameters ◽  
Gas Tungsten Arc ◽  
Erosion Corrosion ◽  
Incoloy 800

Due to high wear resistance and chemical stability at high temperature, cobalt base alloys have presently been used as materials for hardfacing in several applications, for example, coating a head of thermowell, a protecting part for thermocouple, in petrochemical production. One of various techniques used for hardfacing is often weld cladding by using a gas tungsten arc welding (GTAW) method. However, welding parameters should be exactly controlled in order to obtain desired materials due to their structure. The objective of this experiment is to study the influence of the GTAW parameters on the high-temperature erosion-corrosion resistance of Incoloy 800 thermowell cladded by the cobalt-base alloy filler, Stellite12 (Co-29.5Cr-8.5W-1.4C) at 900°C. The studied parameters were welding speed in the range of 0.1-0.9 mm s-1, welding current in the range of 60-75 A, and flow rate of pure Ar used as shield gas in the range 3-20 liter min-1. The results showed that when erosion rates had a tendency to increase with increasing current for all welding speed except 0.8 mm s-1. The erosion rate decreased with the increasing current for the welding speed of 0.8 mm s-1. Using flow rate of 5 liter min-1induced the lowest erosion rate. The optimum GTAW parameters giving the lowest erosion rate were the welding current of 75 A, flow rate of 5 litter min-1, and welding speed of 0.8 mm s-1. However, it was found that hardness results did not correspond to the erosion rate. It was found that high hardness led to heavy mass loss due to the fracture on the surface. From metallographic observation, the oxidation could be observed on the sample surface before the erosion testing. However, the spallation of oxide scale might be involved due to the high erosion rate. It was also observed that the solid solution phases influenced more significantly on the erosion - corrosion resistance than the carbide did.

scholarly journals Effect of Electron Beam Welding Parameters on Temperature and Stress Field of AISI P20 Tool Steel in Vacuum Roll-cladding Process

2021 ◽  
Author(s):  
lanyu mao ◽  
Zongan Luo ◽  
Yingying Feng ◽  
Xiaoming Zhang
Keyword(s):  
Electron Beam ◽  
Stress Field ◽  
Tool Steel ◽  
Welding Speed ◽  
Electron Beam Welding ◽  
Welding Process ◽  
Welding Current ◽  
Temperature Fields ◽  
Welding Parameters ◽  
Aisi P20

Abstract Vacuum roll-cladding (VRC) is an effective method to produce high quality ultra-heavy AISI P20 plate steel. In the process of VRC, reasonable welding process of electron beam welding (EBW) can significantly avoid welding cracks and reduce the cost. In this paper, the electron beam welding process of AISI P20 tool steel was simulated by using a combined heat source model based on finite element method, and the temperature field and stress field under different welding parameters were studied respectively . The results showed that welding parameters have a greater effect on weld penetration than that of weld width, which making the aspect ratio increases with the increase of welding current, and decrease with the increase of welding speed. The weld morphologies were consistent with those of the modeling and the measured thermal heat curves were good agreement with those of simulated, which was verified the feasibility and effectiveness of temperature fields. The results of stress fields under different welding parameters indicat ed that lower welding speed and higher welding current resulting in lower residual stress at welded joint, which means lower risk of cracking after EBW. The results of this study have been successfully applied to industrial production.

scholarly journals Peningkatan Kedalaman Penetrasi Las Stainless Steel 304 dengan Medan Magnet Eksternal pada Pengelasan Autogenous Tungsten Inert Gas Welding

2021 ◽  
Vol 12 (1) ◽  
pp. 87
Author(s):  
Haikal Haikal ◽  
Moch. Chamim ◽  
Deni Andriyansyah ◽  
Apri Wiyono ◽  
Ario Sunar Baskoro ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Welding Speed ◽  
Weld Line ◽  
Welding Process ◽  
Welding Current ◽  
Field Method ◽  
Inert Gas ◽  
Welding Parameters ◽  
Bead Width

<p class="Abstract">In this study, research on the use of the External Magnetic Field method – Tungsten Inert Gas was done to determine the effect of welding arc compression on the quality of <em>AISI 304 </em>thin plate weld. The welding process was performed using autogenous welds. In this study, an external magnetic field was generated by placing a magnetic solenoid around the <em>TIG</em> welding torch. Enabling this electromagnetic field is done dynamically using a microcontroller. Welding parameters used are welding current <em>100; 105; 110 A</em> and welding speed <em>1.6; 1.8; 2.05 mm/s</em>. The results of this study showed that <em>EMF-TIG</em> welding can produce a more uniform bead width along the weld line with a standard deviation of 0.08 compared with conventional <em>TIG </em>welding of <em>0.12</em>. Increased welding speed of  <em>2.05 mm/s</em> causes no effect on the addition of an external magnetic field to the width of the weld bead. The current parameters are <em>105 A </em>with a speed of <em>1.6; 1.8; 2.05 mm/s</em> resulted in compression of the top bead width by <em>0.87; 0.61; 0.1 mm</em>. The welding parameters with a current of 105 A and welding speed of <em>1.6 mm/s</em> have a larger upper bead compression effect of <em>0.84 mm</em> compared to <em>110 A</em> currents of <em>0.38 mm</em>. Moreover, the <em>D/W</em> ratio obtained under an external magnetic field was higher than without magnetic.</p>

The Behaviour of Nitrogen on the Welding Parameters of the Dissimilar Weld Joints between AISI 304 and AISI 316L Austenitic Stainless Steels Produced by Gas Tungsten Arc Welding

2012 ◽  
Vol 248 ◽  
pp. 395-401 ◽  
Author(s):  
Wichan Chuaiphan ◽  
Loeshpahn Srijaroenpramong
Keyword(s):  
Weld Metal ◽  
Nitrogen Content ◽  
Welding Current ◽  
Welding Parameters ◽  
Aisi 316L ◽  
Arc Length ◽  
Aisi 304 ◽  
Dissimilar Weld ◽  
Weld Metals ◽  
Welding Arc

The behavior of nitrogen into the dissimilar joining metal between AISI 304 and AISI 316L Austenitic stainless steel during gas tungsten are welding process was investigated. Studied by using an arc nitrogen atmosphere – controlling in chamber. The relations between nitrogen content of the dissimilar weld metal and the welding parameters, such as the welding current, welding speed, welding arc length and penetration area of weld metals were also evaluated. The results show that the nitrogen content of the weld metals decreased with an increasing welding current, and increasing penetration areas of weld metal, but scarcely depends on the welding arc length. The nitrogen content of the weld metals increased with the welding speed, but decreased penetration areas of weld metals. The role of nitrogen content on the dissimilar weld metals stainless steel is further confirmed by the experimental microstructure, mechanical and corrosion behaviour of the weld metal.

scholarly journals Effect of Parameters Change on the Weld Appearance in Stainless Steel Underwater Wet Welding with Flux-Cored Wire

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 951 ◽  
Author(s):  
Ning Guo ◽  
Xin Zhang ◽  
Changsheng Xu ◽  
Hao Chen ◽  
Yunlong Fu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Welding Speed ◽  
Rapid Development ◽  
Welding Current ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Cored Wire ◽  
Arc Voltage ◽  
Underwater Wet Welding ◽  
Weld Appearance

The underwater wet welding (UWW) technology is rapidly developing as a crucial method in the maintenance work of marine equipment and offshore platform. The rapid development of UWW technology has also exposed the problems to be solved urgently. Therefore, the influence of welding parameters on the weld appearance and welding spatters was investigated in this paper. The main welding parameters used in the study are welding current, arc voltage, welding speed and the contact tip-to-work distance (CTWD). Through the orthogonal test, it is found that, as each welding parameter increases within a certain range, the amounts of welding spatter decreases first and then increases, and the weld forming effect first becomes better and then deteriorates. The amount of wet welding spatter is mainly affected by the welding speed. When the welding speed is low, the splash is more, and the change of the welding current and the arc voltage has a little effect on the number of spatters. When the welding speed is large, the spatter is most with a small welding current and a large arc voltage. After evaluating the weld morphology obtained by welding under various parameters, a set of optimal parameters was obtained. The best parameters for the underwater wet welding of stainless steel with self-shielded flux-cored wire are determined to be 200 A-29 V-2.0 mm/s-15 mm (CTWD).

Parameter optimization of flux-aided backing-submerged arc welding by using Taguchi method

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744046 ◽  
Author(s):  
Juan Pu ◽  
Shengfu Yu ◽  
Yuanyuan Li
Keyword(s):  
Taguchi Method ◽  
Welding Speed ◽  
Arc Welding ◽  
Welding Current ◽  
Submerged Arc Welding ◽  
Weld Bead ◽  
Welding Parameters ◽  
Welding Quality ◽  
Submerged Arc

Flux-aided backing-submerged arc welding has been conducted on D36 steel with thickness of 20 mm. The effects of processing parameters such as welding current, voltage, welding speed and groove angle on welding quality were investigated by Taguchi method. The optimal welding parameters were predicted and the individual importance of each parameter on welding quality was evaluated by examining the signal-to-noise ratio and analysis of variance (ANOVA) results. The importance order of the welding parameters for the welding quality of weld bead was: welding current [Formula: see text] welding speed [Formula: see text] groove angle [Formula: see text] welding voltage. The welding quality of weld bead increased gradually with increasing welding current and welding speed and decreasing groove angle. The optimum values of the welding current, welding speed, groove angle and welding voltage were found to be 1050 A, 27 cm/min, 40[Formula: see text] and 34 V, respectively.

Welding Parameter Optimization of Surface Quality by Taguchi Method

2014 ◽  
Vol 660 ◽  
pp. 109-113
Author(s):  
Chuan Huat Ng ◽  
Mohd Khairulamzari Hamjah
Keyword(s):  
Taguchi Method ◽  
Surface Quality ◽  
Weld Pool ◽  
Welding Current ◽  
Droplet Formation ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Weld Parameters ◽  
Selection Of

An experimental study of GTAW was conducted to determine the optimization of weld parameters on the droplet formation in the surface quality of weld pools. These optimization investigations consisted of welding current, welding speed and feed rate. The strength and surface quality of weld pool were measured for each specimen after the welding parameter optimizations and the effect of these parameters on droplet formation were researched. To consider these quality characteristics together in the selection of welding parameters, the Orthogonal Array of Taguchi method is adopted to analyze the effect of each welding parameter on the weld pool quality, and then to determine the welding parameters with the optimal weld pool quality.

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