Pore formation and its mitigation during hybrid laser/arc welding of advanced high strength steel

Autor: Wei Liu, M. Mazar Atabaki, Radovan Kovacevic, Junjie Ma
Rok vydání: 2015
Předmět:
Zdroj: Materials & Design. 67:509-521
ISSN: 0261-3069
DOI: 10.1016/j.matdes.2014.10.072
Popis: The possible mechanisms of the pores formation and their mitigation during the hybrid laser/arc welding (HLAW) of Advanced High Strength Steel (AHSS) were investigated. Influence of three variables (stand-off distance between the laser and the arc of gas metal arc welding (GMAW), heat input and side shielding gas) in the HLAW for reducing the presence of pores in the weld area was studied. The optimum condition of the welds prepared by the HLAW was compared with the welds made by the laser welding assisted with hot wire. The vision monitoring of the welding processes was performed by a charged coupled device (CCD) camera and mechanical properties of the welds were evaluated by a high energy impact test and microhardness measurement. The joints were characterized by the scanning electron microscopy (SEM) analysis and energy dispersive X-ray spectroscopy (EDS) analysis. The results showed that the optimum stand-off distance between the laser and the tip of wire in the HLAW and laser welding assisted with a hot wire were the most effective approaches for avoiding the pore formation. The fracture surface of the welds was mostly dominated by a brittle fracture with the presence of two types of pores, indicating that there were two mechanisms for the generation of pores in the weld area.
Databáze: OpenAIRE
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