Laser-MIG Hybrid Keyhole Welded 6mm Steel/Aluminum Butt Joints

2019 ◽  
Vol 944 ◽  
pp. 581-592
Author(s):  
Dong Qi Lu ◽  
Li Cui ◽  
Hong Xi Chen ◽  
Yao Qing Chang ◽  
Zhi Bo Peng ◽  
...  
Keyword(s):  
Laser Welding ◽  
Welding Process ◽  
Butt Joint ◽  
Feed Speed ◽  
Welded Steel ◽  
Single Beam ◽  
Beam Laser ◽  
Wire Feed Speed ◽  
Wire Feed ◽  
Laser Welding Process

At present, the connection of steel/aluminum joints has been widely used in industrial fields such as aerospace, marine and automotive.Although the joints with excellent performance can be obtained by the solid phase welding methods such as explosion welding and friction welding, the production process is complicated and the efficiency is low, and the practical application is limited.Laser welding has attracted a lot of attention from researchers because of its advantages of high energy density, small welding deformation and fast welding speed.However, in the single-beam laser welding process, there are problems such as high joint assembly precision, excessive energy density, and easy formation of depressions in the weld.The newly developed laser-MIG (Metal Inert Gas) hybrid welding not only retains the advantages of laser welding, but also fully exploits the advantages of MIG welding, improves weld formation, improves the stability of the welding process, and helps solve the single-beam laser welding problems.In this paper, the laser deep penetration welding process of 5.5 mm thick E36 steel and 6 mm thick 5083 aluminum alloy butt joint was studied by laser-MIG composite welding heat source. Compared with the single laser welding process, the influence of wire feed speed on the welded steel/aluminum joint, joint interface structure and joint mechanical properties was studied.The results show that the laser-MIG composite deep-melt welding can obtain good steel/aluminum butt joint performance. At a laser power of 3.25 kW, a wire feed speed of 1.5 m / min, a laser offset of 0.5 mm and a defocus of 0 mm, the tensile strength of the steel/aluminum butt joint is as high as 85.0 MPa.Laser-MIG hybrid welding can improve the dent defects of a single laser welded steel/aluminum butt joint. The amount of acicular Fe4Al13 phase in the intermetallic compound was significantly reduced, and the resistance of the steel/aluminum joint was increased from 8.6 kN to 12.7 kN.

Correlation between wire feed speed and external mechanical constraint for enhanced process stability in underwater wet flux-cored arc welding

2018 ◽  
Vol 233 (10) ◽  
pp. 2061-2073 ◽  
Author(s):  
Jianfeng Wang ◽  
Qingjie Sun ◽  
Jiangkun Ma ◽  
Peng Jin ◽  
Tianzhu Sun ◽  
...  
Keyword(s):  
Welding Process ◽  
Electrical Signal ◽  
Feed Speed ◽  
Process Stability ◽  
Underwater Wet Welding ◽  
Extinction Process ◽  
Flux Cored Arc Welding ◽  
Wire Feed Speed ◽  
Wire Feed ◽  
Mechanical Constraint

It is a great challenge to improve the process stability in conventional underwater wet welding due to the formation of unstable bubble. In this study, mechanical constraint method was employed to interfere the bubble generated by underwater wet welding, and the new method was named as mechanical constraint assisted underwater wet welding. The aim of the study was to quantify the combined effect of wire feed speed and condition of mechanical constraint on the process stability in mechanical constraint assisted underwater wet welding. Experimental results demonstrated that the introduction of mechanical constraint not only suppressed the bubble without floating but also stabilized the arc burning process. The degree of influence of mechanical constraint, which changed with wire feed speed, played an important role during the mechanical constraint assisted underwater wet welding process. For all wire feed speeds, the fluctuations of welding electrical signal were decreased through introduction of mechanical constraint. The difference in the proportion of arc extinction process between underwater wet welding and mechanical constraint assisted underwater wet welding became less with increasing wire feed speed. At wire feed speed lower than 7.5 m/min, the improvement of process stability was very significant by mechanical constraint. However, the further improvement produced limited effect when the wire feed speed was greater than 7.5 m/min. The observation results showed that a better weld appearance was afforded at a large wire feed speed, corresponding to a lower variation coefficient.

Investigation of Fluid Flow and Heat Transfer in 3D Dual-Beam Laser Keyhole Welding

2010 ◽  
Author(s):  
Jun Zhou ◽  
Hai-Lung Tsai
Keyword(s):  
Heat Transfer ◽  
Laser Welding ◽  
Welding Process ◽  
Solidification Process ◽  
Melt Flow ◽  
Single Beam ◽  
Keyhole Welding ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Keyhole Welding

Dual-beam laser welding has become an emerging joining technique. Studies have demonstrated that it can provide benefits over conventional single-beam laser welding, such as increasing keyhole stability, slowing down cooling rate and delaying the humping onset to a higher welding speed. It is also reported to be able to improve weld quality significantly. However, due to its complexity the development of this promising technique has been limited to the trial-and-error procedure. In this study, mathematical models are developed to investigate the heat transfer, melt flow, and solidification process in three-dimensional dual-beam laser keyhole welding. Effects of key parameters, such as laser-beam configuration on melt flow, weld shape, and keyhole dynamics are studied. Some experimentally observed phenomena, such as the changes of the weld pool shape from oval to circle and from circle to oval during the welding process are analyzed in current study.

Application of MIG Welding Process of Mild Steel Wire in Additive Manufacturing

2021 ◽  
Vol 877 ◽  
pp. 73-79
Author(s):  
Pattarawadee Poolperm ◽  
Wasawat Nakkiew ◽  
Nirut Naksuk
Keyword(s):  
Additive Manufacturing ◽  
Steel Wire ◽  
Welding Process ◽  
Feed Speed ◽  
Mig Welding ◽  
Microhardness Testing ◽  
Wire Feed Speed ◽  
Forming Characteristics ◽  
Arc Current ◽  
Wire Feed

The purpose of this study is to investigate the forming characteristics of single-pass Metal Inert Gas (MIG) welding wire for multi-layer additive manufacturing parts. Influences of arc current, arc voltage, arc distances, welding speed, wire feed speed, temperatures and heat input on layer formation were analyzed. The deposition of material by MIG process is controlled by a robot (ABB) controller for constructing walls of rectangular box shape. The samples were measured with a microhardness testing and tensile testing onto the welded bead created by the additive manufacturing technique. It was found that the mechanical properties of microhardness values are between 151.70 to 155.80 HV and the tensile strength values are between 472.71 to 491.12 MPa according to transverse and longitudinal sections of the specimens.

scholarly journals Research on Parameters of Wire-Filling Laser Welding and Quenching Process for Joints Microstructure and Mechanical Property of BR1500HS Steel

2021 ◽  
Author(s):  
Lianpu Zhou ◽  
Chundong Zhu ◽  
Rongfei Ma ◽  
Zihao Wei
Keyword(s):  
Laser Welding ◽  
Heat Input ◽  
Boron Steel ◽  
Feed Speed ◽  
Curve Shape ◽  
Quenching Process ◽  
Hyperbolic Curve ◽  
Wire Feed Speed ◽  
Wire Feed ◽  
Grain Diameter

With the aim to investigate the effect of parameter and quenching process on the joint of hot stamping steel by laser welding, the BR1500HS boron steel was welded by filling-wire laser welding with ER70-G welding wire under different parameters. The welded specimens were heated to 900℃ and held for 5min before water quenching. The universal material test machine, Optical micro-scope, Vickers hardness tester, scanning electron microscope and electron backscatter diffraction (EBSD) were used to characterize. The results showed that the macroscopic morphology of fusion zone (FZ) becomes from funnelform to hyperbolic curve shape when heat input increases and from hyperbolic curve shape to funnelform when wire-feed speed increases. The strength after quenching is more than 1557Mpa at heat input of 1040J/cm, wire feeding speed of 1.6m/min~1.8m/min and welding speed of 1.5m/min. EBSD test showed that the FZ and fine grain zone (FGZ) have more retained austenite (RA) than coarse grain zone (CGZ) before quenching and RA in FZ and heat affect zone (HAZ) decreased and distributed uniformed after quenching. The grain diameter in FZ distribute unevenly, with the maximum grain diameter larger than 40μm before quenching. After quenching, the grain diameter of FZ, HAZ and BM is more even and coarse grains in the FZ was refined. Before quenching, the microhardness of FZ and HAZ is of 450HV~500HV at different heat input and wire-feed speed and all region of joint keeps at 450HV~550HV after quenching. Most dimple and little river pattern in the joint fracture mor-phology before quenching indicates a well plasticity and most cleavage facet is observed after quenching due to the joint combine with martensite.

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