Keyhole depth instability in case of CW CO2 laser beam welding of mild steel

摘要: The study of keyhole (KH) instability in deep penetration laser beam welding (LBW) is essential to understand process and appearance weld seam defects. main cause collapse the KH dynamics during LBW process. This mainly due surface tension forces associated with stabilizing action vapour pressure. A high power CW CO2 was used generate mild steel (MS) two different conditions i.e. ambient atmospheric (AAW) under water (UWW). KH, formed case welding, deeper narrower than condition. number dimensions irregular humps increased condition larger rapid also studied. thermocapillary convection considered explain instability, which turn gives rise humps.