Effect of Weld Pool Flow and Keyhole Formation on Weld Penetration in Laser-MIG Hybrid Welding within a Sensitive Laser Power Range

The weld penetration variation in laser-MIG hybrid welding under sensitive laser power range was investigated by welding experiments and CFD (computational fluid dynamics) simulation. During this investigation, joints of AH36 sheets were welded with varying laser powers by the laser-MIG hybrid welding process. In addition, the CFD model was established based on experimental parameters and measurement results. Moreover, surface tension, electromagnetic force, buoyancy, recoil pressure, evaporative condensation, evaporative heat exchange, melt drop transfer, and other factors were considered. The influence of various factors on molten pool depth and keyhole depth were studied, including temperature, velocity, and flow direction of liquid metal. The results show that the weld-forming effect is better at the laser power is 7.5 kW in the range of sensitive laser power. After the keyhole is formed, its depth gradually entered the stage of linear increase, oscillation increase, and oscillation balance. Increasing the laser power can effectively shorten the time of the two growth stages and allow the keyhole to enter the balance stage earlier. During the oscillation balance state of the keyhole, the molten metal under the keyhole flowed to the molten pool root in the reverse direction of welding; it can also promote weld penetration.

[1]  Sangwoo Han,et al.  Coupled simulation of thermal-metallurgical-mechanical behavior in laser keyhole welding of AH36 steel , 2021, Materials & Design.

[2]  Bo Chen,et al.  Influence of energy ratio on microstructure and mechanical properties in the transition zone of hybrid laser-MIG welded AH36/316L dissimilar joints , 2021, Journal of Materials Research and Technology.

[3]  Zhaodong Zhang,et al.  The effect of low-power laser on micro-forming of 316 stainless steel additive manufacturing part , 2021 .

[4]  Chang-Da Wen,et al.  Examination of molten pool with Marangoni flow and evaporation effect by simulation and experiment in selective laser melting , 2021 .

[5]  Y. Lo,et al.  Numerical simulation and experimental validation of melting and solidification process in selective laser melting of IN718 alloy , 2020 .

[6]  Liangliang Bao,et al.  Numerical and experimental investigation of the formation mechanism and the distribution of the welding residual stress induced by the hybrid laser arc welding of AH36 steel in a butt joint configuration , 2020 .

[7]  Xiong Zhang,et al.  Microstructure and performance of hybrid laser-arc welded high-strength low alloy steel and austenitic stainless steel dissimilar joint , 2020 .

[8]  Lijin Huang,et al.  Experimental research on formation mechanism of porosity in magnetic field assisted laser welding of steel , 2020 .

[9]  Y. Lo,et al.  Effects of sulfur concentration and Marangoni convection on melt-pool formation in transition mode of selective laser melting process , 2019, Materials & Design.

[10]  R. Kovacevic,et al.  Numerical prediction and experimental analysis of the residual stress fields and generated distortion in hybrid laser/arc welded thick plates of high-strength steels , 2018, The International Journal of Advanced Manufacturing Technology.

[11]  Bappa Acherjee,et al.  Hybrid laser arc welding: State-of-art review , 2018 .

[12]  Shaoxia Li,et al.  Effect of droplet impact on molten pool dynamics in hybrid laser-MIG welding of aluminum alloy , 2018 .

[13]  Gaoyang Mi,et al.  Effects of Welding Speed on Microstructure and Mechanical Property of Fiber Laser Welded Dissimilar Butt Joints between AISI316L and EH36 , 2017 .

[14]  Asish Bandyopadhyay,et al.  Comparative study of pulsed Nd:YAG laser welding of AISI 304 and AISI 316 stainless steels , 2017 .

[15]  M. Hermans,et al.  Control of welding distortion during gas metal arc welding of AH36 plates by stress engineering , 2017 .

[16]  Y. Abe,et al.  Development of narrow gap multi-layer welding process using oscillation laser beam , 2017 .

[17]  Xiaoxiang Zhang,et al.  The impacts of economic importance difference of a joint venture (JV) held by partners and partners' size difference on the extraction of rivalrous and non-rivalrous private benefits in a JV , 2016 .

[18]  S. Katayama,et al.  High-Speed X-Ray Transmission and Numerical Study of Melt Flows inside the Molten Pool during Laser Welding of Aluminum Alloy , 2016 .

[19]  S. H. Seyedein,et al.  Numerical modeling of heat transfer and fluid flow in hybrid laser–TIG welding of aluminum alloy AA6082 , 2014, The International Journal of Advanced Manufacturing Technology.

[20]  Shuangyue Liu,et al.  Experimental investigation on arc characteristic and droplet transfer in CO2 laser–metal arc gas (MAG) hybrid welding , 2013 .

[21]  R. Yılmaz,et al.  Microstructural studies and impact toughness of dissimilar weldments between AISI 316 L and AH36 steels by FCAW , 2013 .

[22]  Zhang Shenghai,et al.  The technology and welding joint properties of hybrid laser-tig welding on thick plate , 2013 .

[23]  Wiesława Piekarska,et al.  Three-dimensional model for numerical analysis of thermal phenomena in laser–arc hybrid welding process , 2011 .

[24]  Yixiong Wu,et al.  Analysis of weld pool dynamic during stationary laser–MIG hybrid welding , 2009 .

[25]  D. Petring,et al.  Joining of thick section steels using hybrid laser welding , 2008 .

[26]  X. Zhan,et al.  Influence of laser power on molten pool flow field of laser-MIG hybrid welded Invar alloy , 2021 .

[27]  Hui Chen,et al.  Heat propagation of circular thin-walled parts fabricated in additive manufacturing using gas metal arc welding , 2018 .

[28]  Jianmin Chen,et al.  Numerical simulation of keyhole behaviors and fluid dynamics in laser–gas metal arc hybrid welding of ferrite stainless steel plates , 2017 .

[29]  S. H. Seyedein,et al.  Effects of welding parameters on weld pool characteristics and shape in hybrid laser-TIG welding of AA6082 aluminum alloy: numerical and experimental studies , 2015, Welding in the World.