keyhole mode plasma arc welding

例句：

1. 1.The keyhole mode plasma arc welding is widely used in the construction industry.
   激光焊是一种广泛应用于建筑业的焊接技术。
2. 2.In this method, the keyhole mode plasma arc welding is used to weld steel plates together.
   在此方法中，使用激光焊将钢板焊接在一起。
3. 3. The keyhole mode plasma arc welding has many advantages over traditional welding methods.
   与传统焊接方法相比，激光焊具有许多优点。