Back Bead Characteristics during Butt Welding of a Thick Plate for Various Backing Conditions

2010 ◽  
Vol 654-656 ◽  
pp. 350-353 ◽  
Author(s):  
Cheol Hee Kim
Keyword(s):  
Fatigue Strength ◽  
Arc Welding ◽  
Thick Plate ◽  
Gas Metal Arc Welding ◽  
Butt Joint ◽  
Butt Welding ◽  
Weld Defects ◽  
Metal Arc Welding ◽  
Welded Structure ◽  
Job Site

In a welded structure, thick plates are joined by multi-pass welding in the butt joint. During the first pass of multi-pass welding, burn-through, lack of fusion, and incomplete penetration were readily found as weld defects. Accordingly, the backing condition should be carefully selected in welding of a thick plate, because improper backing conditions lead to weld defects. In the job site, a steel backing strip is usually adopted, although it reduces the fatigue strength. No backing conditions or removable backing is recommended to increase the fatigue strength, but selection of the proper backing and welding conditions is complicated. In this study, several backing methods, such as ceramic backing, water-cooled copper backing, and even the use of no backing, were investigated during GMA (Gas Metal Arc) welding of a thick steel plate. The gas metal arc welding conditions were established for each backing method, and the bead shape and mechanical properties were examined after welding.

scholarly journals Effects of High Frequency Mechanical Impact on Fatigue Life of Semi-Automated Gas Metal Arc Welding (GTAW) of HSLA Butt Weld

2019 ◽  
Vol 269 ◽  
pp. 06002
Author(s):  
Salina Saidin ◽  
Dahia Andud ◽  
Yupiter H. P. Manurung ◽  
Muhd. Faiz Mat ◽  
Noridzwan Nordin ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Steel Structure ◽  
Welding Parameters ◽  
Butt Weld ◽  
Metal Arc Welding ◽  
Life Enhancement ◽  
Fatigue Life Enhancement

This paper deals with a comprehensive investigation of fatigue life enhancement on semiautomated Gas Metal Arc Welding (GTAW) butt weld joint which is found almost everywhere in Malaysia welding structure steel sectors. The selected material in this study was high strength low alloy steel S460G2+M commonly used extremely in steel structure due to its outstanding mechanical properties. In this investigation, the method for joining the butt weld was conducted by unprofessional welder using semi-automated GMAW. At first, suitable welding parameters were identified and formulated into welding procedure specification (WPS) qualification conforming to AWS D1.1 standard. The test specimens were prepared and tested to ensure the welding quality. Further, the HFMI using Pneumatic Impact Treatment (PIT) technique were applied at the weld toe of the butt weld as tool for fatigue life enhancement. To investigate the influence of HFMI/PIT on the fatigue strength, the specimens were undergone fatigue test using universal fatigue machine using a constant amplitude loading. Finally, the comparison of the fatigue strength of as welded and treated specimens to indicate the beneficial influence of the treatment. Yes, the conduction by unprofessional welder using semi-automatic GMAW, the findings showed the improvement of fatigue strength and slope of S-N curves. In addition, the fracture location of test specimen shows physically affected by shifting from critical weld transition to base metal. The tensile test and hardness value also showed a slight difference as compared to untreated specimens.

Tandem laser-gas metal arc welding joining of 20 mm thick super duplex stainless steel: An experimental and numerical study

2020 ◽  
Vol 234 (5) ◽  
pp. 697-710
Author(s):  
A Mathieu ◽  
I Tkachenko ◽  
JM Jouvard ◽  
I Tomashchuk
Keyword(s):  
Numerical Simulation ◽  
Heat Source ◽  
Laser Beam ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Image Correlation ◽  
Angular Distortion ◽  
Metal Arc Welding ◽  
Welded Structure ◽  
Welding Processes

The present work covers the topic of strains and stresses prediction in case of welded steel structures. Steel sheets of 20 mm thickness made in UR™2507Cu are welded using a laser and gas metal arc welding processes combination. The focused laser beam leads the arc in a Y-shape chamfer geometry. Both sources are 20 mm apart from each other in order to avoid any synergic effect with each other. In order to predict residual strain, a 3D unsteady numerical simulation has been developed in COMSOL finite element software. A volume heat source has been identified based on the temperature measurements made by 10 K-type thermocouples, implanted inside the workpiece. The 50 mm deep holes are drilled in the workpiece using dye-sinking Electrical Discharge Machining (EDM) machine. Before the implantation in the hole, each thermocouple is surrounded by Inconel sheathing. Hot junctions of the thermocouples are positioned in a way to feel two advancing molten pools. The equivalent heat source is composed of three sources. First one is a Goldak source that represents the molten pool induced by gas metal arc welding. The second one is a cylinder with an elliptic cross-section that represents the focused laser beam penetrating into the workpiece. The third one is a surface Gaussian source that represents energy radiated by arc and blocked by workpiece surface. Concerning mechanical simulation, an elasto-plastic behavior with isotropic hardening is implemented. A weak coupling is established between equations governing heat transfer and mechanics thanks to the temperature dependent coefficient of linear expansion. This numerical simulation made with some simplifying assumptions predicts an angular distortion and a longitudinal shrinkage of the welded structure. The numerical results are consistent with the displacements measured by digital image correlation method.

INVESTIGATION ON CORROSION RATE OF BUTT-JOINT IN GAS METAL ARC WELDING, FLUX CORE ARC WELDING AND SUBMERSIBLE ARC WELDING

2015 ◽  
Vol 76 (6) ◽  
Author(s):  
Bulan Abdullah ◽  
Syuhada Ismail ◽  
Muhammad Hafizuddin Jumadin
Keyword(s):  
Corrosion Rate ◽  
Arc Welding ◽  
Sea Water ◽  
Gas Metal Arc Welding ◽  
Butt Joint ◽  
Corrosion Process ◽  
Welding Flux ◽  
Metal Arc Welding ◽  
Current Voltage ◽  
Different Types

Corrosion can be defined as the destructive attack of a metal through interaction with its environment. Different type of welding can be factors that contribute to the corrosion and erosion problems since this type of welding will lead the material to expose with the corrosion and erosion agents like salt, air , water and material composition, dissolved oxygen content in the fluid, pH and fluid’s velocity characteristics. Research was carried out in order to investigate the corrosion rate on mild steel at 3 different types of welding which are Gas Metal Arc Welding (GMAW), Flux Core Arc Welding (FCAW) and Submersible Arc after exposed in 3 types of solution; sea water, sodium chloride and reverse osmosis (RO). In each of the types of welding, the parameters were fixed that includes of current, voltage and speed of travel. Immersion and polarisation test using Gamry instruments test were conducted to distinguish the corrosion rate. Results showed SAW had a least corrosion rate than FCAW and GMAW and morphology transformation differences occur during the corrosion process.

scholarly journals Characteristic of Weld Bead By Using Flat Wire Electrode In GMAW Inline During The Process: An Experimental And Numerical Analysis

2021 ◽  
Author(s):  
K Sripri ◽  
M Ramu ◽  
P R Thyla ◽  
K Anantharuban ◽  
M Karthigha
Keyword(s):  
Steady State ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Butt Joint ◽  
Weld Bead ◽  
Wire Electrode ◽  
Molten Droplet ◽  
Metal Arc Welding ◽  
Steady State Temperature

Abstract This paper focusses on effect of flat wire electrode on gas metal arc welding (FW-GMAW) inline during the process to improve quality of weld bead. Since the flat wire electrode perimeter has enlarged, the turbulence of the molten droplet characteristics is altered due to the effect of electromagnetic force. To bring out, butt joint welding are proven with use of the flat wire electrode. The experimental results indicated that, the flat wire electrode and their orientations are significantly factors to improve the weld bead dimensions, due to the increased in steady state temperature and heat density. The end result also evident that the depth-to-width (D/W) ratio was improved on an average by 7.7 % than regular wire electrode used in GMAW. To validate, a comprehensive numerical model was developed, the result confirmed that the initial arc and steady state temperature are high for FW-GMAW. In addition, improvements in metallurgical and mechanical properties are discussed in this paper.

Modeling and Simulation of Mecano-Welding Process for Cylinders

2012 ◽  
Author(s):  
Zhengkun Feng ◽  
Henri Champliaud
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Arc Welding ◽  
Thick Plate ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
The Third ◽  
Metal Arc Welding ◽  
Roll Bending ◽  
Arc Welding Process

Pyramidal three-roll bending is widely used in manufacture due to its simple configuration and advantage for thick plate roll bending. However, there remain two planar zones near the front and rear ends of the bent shape. A mecano-welding process which provides improved circularity of the bent shape is proposed in this paper. This process includes three sub-processes: the first sub-process is the roll bending from a plate with cylindrical rolls; the second sub-process is the gas metal arc-welding process used to join the gap of the bent tubular section; the third sub-process is the rerun roll bending of the welded shape. Results of the numerical simulation of the first two sub-processes under the well-known ANSYS and ANSYS/LS-DYNA environment are reported. The bent shape after the first roll bending, the distributions of the temperature and residual stress after the welding are illustrated and discussed.

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