Experimental and numerical investigation of an electromagnetic weld pool support system for high power laser beam welding of austenitic stainless steel
Experimental and numerical investigation of an electromagnetic weld pool support system for high power laser beam welding of austenitic stainless steel
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DOI：
10.1016/j.jmatprotec.2013.11.013
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发表时间：
2014-03-01
影响因子：
6.3
通讯作者：
Rethmeier, Michael
中科院分区：
文献类型：
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作者：
Bachmann, Marcel;Avilov, Vjaceslav;Rethmeier, Michael
采用三维湍流稳态数值模型，研究了交流磁场对20 mm厚不锈钢AISI 304理想非铁磁材料激光小孔焊接过程的影响。利用COMSOL多物理4.2有限元程序对三维传热和流体力学以及电磁场方程进行了求解，考虑了过程中最重要的物理效应。该模型考虑了熔池边界处的热毛细(Marangoni)对流、熔体体积重力和密度差异引起的自然对流以及相界处固-液相变潜热的影响。结果表明，在焊接试件下方1 kHz~10 kHz范围内施加80 mT~135 mT的交流磁场，可以防止由于静水压力引起的厚板焊接过程中的重力下降。实验发现，对于厚度为20 mm的奥氏体不锈钢AISI 304和铁素体结构钢S235JRC在约2.6 kHz的振荡频率下进行单道激光焊接，磁感应强度约为230mT是必要的，才能实现无下垂或熔体脱落的单道激光焊接。(C)2013爱思唯尔B.V.保留所有权利。
A three-dimensional turbulent steady state numerical model was used to investigate the influence of an alternating current (AC) magnetic field during high power laser beam keyhole welding of 20 mm thick stainless steel AISI 304 being modeled as an ideal non-ferromagnetic material. Three-dimensional heat transfer and fluid dynamics as well as the electromagnetic field equations were solved with the finite element package COMSOL Multiphysics 4.2 taking into account the most important physical effects of the process. Namely, the thermo-capillary (Marangoni) convection at the weld pool boundaries, natural convection due to gravity and density differences in the melt volume as well as latent heat of solid-liquid phase transitions at the phase boundaries were included in the model.It is shown that the gravity drop-out associated with the welding of thick plates due to the hydrostatic pressure can be prevented by the application of AC magnetic field between 80 mT and 135 mT for corresponding oscillation frequencies between 1 kHz and 10 kHz below the weld specimen. Experimentally, a value of the magnetic flux density of around 230 mT was found to be necessary to allow for single-pass laser beam welding without sagging or drop-out of melt for a 20 mm thick combination of austenitic stainless steel AISI 304 and ferritic construction steel S235JRC at an oscillation frequency of around 2.6 kHz. (C) 2013 Elsevier B.V. All rights reserved.