Effect of laser welding speed on pore formation in AA 6061 T6 alloy

2020 ◽  
Vol 62 (10) ◽  
pp. 979-984
Author(s):  
Emine Gündoğdu İş ◽  
Erhan Akman ◽  
Muharrem Yilmaz ◽  
Polat Topuz
Keyword(s):  
Laser Welding ◽  
Welding Speed ◽  
Welded Joints ◽  
Pore Formation ◽  
Weld Seam ◽  
Welding Process ◽  
Tensile Tests ◽  
Fiber Laser Welding ◽  
Thick Plates ◽  
Hardness Tests

Abstract In this study, 6 mm thick plates of Al 6061 T6 alloy are joined by laser welding at four welding speeds (40 mm × s-1, 35 mm × s-1, 25 mm × s-1, and 20 mm × s-1). The welded joints are made using a 4000 W fiber laser welding machine. The effect of laser welding speed on the pores formed in the weld seam was investigated. In this manner, it was found that with a change in laser welding speed the amount of pores formed in the structure also changed. In addition, after the welding process, macroscopic examinations, tensile tests and the hardness tests were made. As a result of the experiments performed, it was determined that, the laser welding speed was highly effective for pore formation.

Weld Seam Deviation Detection Base on Laser Welding Pool’s Centroid

2013 ◽  
Vol 690-693 ◽  
pp. 2594-2597
Author(s):  
Ren He Zhen
Keyword(s):  
Laser Welding ◽  
High Speed ◽  
Near Infrared ◽  
Weld Seam ◽  
Welding Process ◽  
Infrared Camera ◽  
Fiber Laser Welding ◽  
Welding Pool ◽  
Welding Equipment ◽  
Set Up

For detecting weld seams deviation during the industrial actual welding process, IPG YLR-10000 high power fiber laser welding equipment was used during laser welding experiments. A high-speed near-infrared camera was used to capture the dynamic welding pool image sequences. Through studying the change of the features of near-infrared images of the weld pool when the laser beam deviated the weld seam, the centroid of the welding pool could be used as the deviated parameter of the weld seam. The welding pool images coordinates were established, and the ways of rotating and shifting the coordinates were used to build a model to test the welding spots deviation. Finally, the model of the relationship of the actual weld seam deviation and the tested weld seam deviation had been set up by using the regression analysis method. Its validity and feasibility had been tested by analyzing the models correlation R parameters.

Fiber Laser Welding of Noncombustible Magnesium Alloy

2008 ◽  
Vol 580-582 ◽  
pp. 479-482 ◽  
Author(s):  
Yuji Sakai ◽  
Kazuhiro Nakata ◽  
Takuya Tsumura ◽  
Mitsuji Ueda ◽  
Tomoyuki Ueyama ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Magnesium Alloy ◽  
Laser Welding ◽  
Fiber Laser ◽  
Vickers Hardness ◽  
Laser Power ◽  
Welded Joint ◽  
Welding Process ◽  
Fiber Laser Welding ◽  
Laser Welding Process

Noncombustible magnesium alloy AMC602 (Mg-6mass%Al-2mass%Ca) extruded sheet of 2.0mm thickness was successfully welded using a fiber laser welding process at welding speed of 10m/min at 3kW laser power. Tensile strength of the welded joint was about 82 to 88% of that of the base metal. Vickers hardness, tensile strength and micro structural properties are also discussed.

scholarly journals A Study on Determining Weld Joint Hardening and a Quality Evaluation Algorithm for 9% Nickel Weld Joints Using the Dilution Ratio of the Base Material in Fiber Laser Welding

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1308
Author(s):  
Minho Park ◽  
Jisun Kim ◽  
Changmin Pyo ◽  
Jaewoong Kim ◽  
Kwangsan Chun
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
Weld Joint ◽  
Base Material ◽  
Welding Process ◽  
Fuel Oil ◽  
Welding Quality ◽  
Dilution Ratio ◽  
Fiber Laser Welding ◽  
Evaluation Algorithm

The demand for LNG-powered ships and related equipment is rapidly increasing among major domestic and foreign carriers due to the strengthened IMO regulations on the sulfur content of ship fuel oil. LNG operation in a cryogenic environment requires a storage tank and fuel supply system that uses steel with excellent brittleness and fatigue strength. A ship using LNG is very sensitive to explosion and fire. For this reason, 9% Ni is often used, because ships require high quality products with special materials and structural technologies that ensure operability at cryogenic temperatures. However, research to derive uniform welding quality is urgent because the deterioration of weld quality in the 9% Ni steel welding process is caused by high process difficulty and differences in welding quality depending on a welder’s skill set. This study proposes a method to guarantee a uniform quality of 9% Ni steel in a fiber laser welding process by categorizing weld joint hardness according to the dilution ratio of a base material and establishing a standard for quantitative evaluation.

Effect of Welding Speed on Melt Flow Behavior in High Speed Laser Welding Process

2013 ◽  
Vol 40 (5) ◽  
pp. 0503001
Author(s):  
裴莹蕾 Pei Yinglei ◽  
单际国 Shan Jiguo ◽  
任家烈 Ren Jialie
Keyword(s):  
Laser Welding ◽  
Welding Speed ◽  
High Speed ◽  
Flow Behavior ◽  
Welding Process ◽  
Melt Flow ◽  
Laser Welding Process

High-power fiber laser welding of thick steel at low welding speed

2007 ◽  
Author(s):  
Xudong Zhang ◽  
Eiji Ashida ◽  
Seiji Katayama ◽  
Masami Mizutani ◽  
Yusuke Anma ◽  
...  
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
High Power ◽  
Welding Speed ◽  
Fiber Laser Welding ◽  
Thick Steel

Estimation of Residual Stresses in Steel Welded Joints Using Three Dimensional Finite Element Analysis

2018 ◽  
Author(s):  
Shivdayal Patel ◽  
B. P. Patel ◽  
Suhail Ahmad
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Residual Stresses ◽  
Boundary Conditions ◽  
Welding Speed ◽  
Welded Joints ◽  
Plate Thickness ◽  
Welding Process ◽  
Element Analysis

Welding is one of the most used joining methods in the ship industry. However, residual stresses are induced in the welded joints due to the rapid heating and cooling leading to inhomogenously distributed dimensional changes and non-uniform plastic and thermal strains. A number of factors, such as welding speed, boundary conditions, weld geometry, weld thickness, welding current/voltage, number of weld passes, pre-/post-heating etc, influence the residual stress distribution. The main aim of this work is to estimate the residual stresses in welded joints through finite element analysis and to investigate the effects of boundary conditions, welding speed and plate thickness on through the thickness/surface distributions of residual stresses. The welding process is simulated using 3D Finite element model in ABAQUS FE software in two steps: 1. Transient thermal analysis and 2. Quasi-static thermo-elasto-plastic analysis. The normal residual stresses along and across the weld in the weld tow region are found to be significant with nonlinear distribution. The residual stresses increase with the increase in the thickness of the plates being welded. The nature of the normal residual stress along the weld is found to be tensile-compressive-tensile and the nature of normal residual stress across the weld is found to be tensile along the thickness direction.

scholarly journals Assessment of the Effect of Laser Welding on the Properties and Structure of TMCP Steel Butt Joints

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1312 ◽  
Author(s):  
Jacek Górka
Keyword(s):  
Laser Beam ◽  
Welded Joints ◽  
Research Work ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Tensile Tests ◽  
Carbon Equivalent ◽  
Quality Level ◽  
Butt Joints ◽  
Plastic Properties

The research work and related tests aimed to identify the effect of filler metal-free laser beam welding on the structure and properties of butt joints made of steel 700MC subjected to the TMCP (thermo-mechanically controlled processed) process. The tests involved 10-mm thick welded joints and a welding linear energy of 4 kJ/mm and 5 kJ/mm. The inert gas shielded welding process was performed in the flat position (PA) and horizontal position (PC). Non-destructive testing enabled classification of the tested welded joints as representing the quality level B in accordance with the requirements set out in standard 13919-1. Destructive tests revealed that the tensile strength of the joints was 5% lower than S700MC steel. The results of tensile tests and changes in structure were referred to joints made using the MAG (Metal Active Gas) method. The tests of thin films performed using a high-resolution scanning transmission electron microscope revealed that, during laser beam welding, an increase in dilution was accompanied by an increase in the content of alloying microadditions titanium and niobium, particularly in the fusion area. A significant content of hardening phases in the welded joint during cooling led to significant precipitation hardening by fine-dispersive (Ti,Nb)(C,N) type precipitates being of several nanometres in size, which, in turn, resulted in the reduction of plastic properties. An increase in the concentration of elements responsible for steel hardening, i.e., Ti and Nb, also contributed to reducing the weld toughness below the acceptable value, which amounts to 25 J/cm2. In cases of S700MC, the analysis of the phase transformation of austenite exposed to welding thermal cycles and the value of carbon equivalent cannot be the only factors taken into consideration when assessing weldability.

Optimization for Laser Welding Fillet Joint Based on Response Surface Method

2011 ◽  
Vol 211-212 ◽  
pp. 1110-1114
Author(s):  
Xiao Yun Zhang ◽  
Yan Song Zhang
Keyword(s):  
Laser Welding ◽  
Response Surface ◽  
Weld Seam ◽  
Welding Process ◽  
Galvanized Steel ◽  
Plant Production ◽  
Welding Parameters ◽  
Technical Instructions ◽  
Fillet Joint ◽  
Laser Welding Process

The wide use of galvanized steel in automobile manufacturing brings much challenge to the roof to body-side laser welding process. Fillet joint is an effective way to solve this problem such as pore in laser welding process. However, there is little research on this type of complicated joint process. Focused on this problem, take metallographic size of weld seam as the weld quality criteria, response surface methodology (RSM) is used to study the influence of laser welding parameters on weld seam quality. Finally, the optimum welding parameters are concluded to give technical instructions for the plant production.

scholarly journals Determination of Strain and Stress Fields in Welded Joints of S960-QC Steel

2017 ◽  
Vol 62 (4) ◽  
pp. 2081-2087 ◽  
Author(s):  
T. Pała ◽  
I. Dzioba
Keyword(s):  
Welded Joints ◽  
Experimental Studies ◽  
Welding Process ◽  
Tensile Tests ◽  
Stress Fields ◽  
Uniaxial Tensile ◽  
Displacement Fields ◽  
The Individual ◽  
Computational Part

Abstract The paper presents the results of two butt welded joints by conventional method. The welding process was performed using a variety of linear welding energy. The studies included experimental and computational part. In experimental studies determined the distribution of hardness and mechanical properties of the individual analyzed sections of welded joints. The data obtained were intended to determine the extent of zones in the welded joints that have certain strength characteristics. Also conducted uniaxial tensile tests of welded joints with the registration of displacement fields on the surface of specimens by means of Aramis video-system what the final result are images of strain fields map on the surface of welded joints. The resulting strain values were compared with the results of numerical computations FEM.

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