The stability of the keyhole decreases for deep penetrated high-power laser beam welding. The keyhole tends to collapse with increasing laser power and e.g. keyhole induced porosity can occur. This study deals with the observation of the keyhole during high-power laser beam welding in partial penetration mode by means of a high-speed camera. A butt configuration of 25 mm thick structural steel and transparent quartz glass was used for the experiments. An oscillating magnetic field was applied perpendicular to the welding direction on the root side of the steel plate. The keyhole was highlighted with a coaxial diode laser. It was ascertained that the stability of the keyhole and the weld penetration depth were increased by applying an oscillating magnetic field with an oscillating frequency of 1.2 kHz and a magnetic flux density of 50 mT.

对于深穿透大功率激光束焊接，锁孔的稳定性降低。随着激光功率的增加，钥匙孔趋于塌陷，例如，可能发生钥匙孔引起的孔隙率。这项研究的目的是通过高速相机在部分穿透模式下进行大功率激光束焊接期间的锁眼观察。实验使用25 mm厚的结构钢和透明石英玻璃的对接配置。垂直于焊接方向在钢板的根部侧施加振荡磁场。锁眼用同轴二极管激光器突出显示。已确定，通过施加振荡频率为1.2 kHz且磁通密度为50 mT的振荡磁场，可以提高锁孔的稳定性和焊缝熔深。