Surface Flow Behavior of Laser-arc Hybrid Welding Pool of High Nitrogen Steel

doi:10.3901/JME.2018.22.055

Abstract

Abstract: The results of the study reveal the effect of welding process parameters on theflow state of the molten pool surface. The flow behavior of the molten pool is one of the critical factors which affect the weld forming and the quality of the joints, while its characteristics are difficult to obtain directly. The ZrO₂ particles are used as tracers, and high-speed camera is used to observe the trajectories of tracer particles. Several experiments with laser-arc hybrid welding are carried out to investigate the flow behavior of the molten pool of high nitrogen steel. The results show that the flow of the molten pool is mainly affected by the change of the size of the keyhole during laser welding. However, the flow of the molten pool during the process of arc welding is mainly influenced by the arc pressure and the impact force generated when the droplet enters the bath. In the process of laser-arc hybrid welding, the molten pool flow is not only affected by the arc pressure and the impact force generated when the droplet enters the molten pool, but the presence of the keyhole will also affect the flow of the molten pool. During laser-arc hybrid welding, the moving line distance of tracer particles increases with the increase of welding current and arc voltage, while the change of laser power does not affect significantly. The results of this study reveal the effect of different weldingprocesses and their parameters on the flow behavior of the molten pool surfaceof high nitrogen steels,which provides a theoretical basis for the selection of high nitrogen steel welding process.

Key words: flow behavior of molten pool, high nitrogen steel, laser-arc hybrid welding, tracer particles

CLC Number:

TG456

LIU Jia, BAI Chenming, SHI Yan, LI Zhong, ZHANG Hong. Surface Flow Behavior of Laser-arc Hybrid Welding Pool of High Nitrogen Steel[J]. Journal of Mechanical Engineering, 2018, 54(22): 55-62.

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