METHOD FOR UNDERWATER LASER CUTTING OF METAL STRUCTURES Russian patent published in 2021 - IPC B23K26/122 B23K26/38 

FIELD: working of metal.

SUBSTANCE: invention relates to a method for underwater laser cutting of metal structures and can be used for underwater building works, repair of underwater pipelines, disassembly of metal buildings and structures, cutting sunken objects apart for lifting thereof, as well as in the nuclear industry for cutting nuclear reactor vessels. The method includes heating a section of the cut metal surface in a water medium to the melting point or a higher temperature by means of laser emission transmitted via a fibre-optic channel and an optical system focusing the laser emission from the end of the fibre-optic channel onto the cut surface. A gas bubble is formed over the cutting site. Two gas bubbles are formed for cutting by two gas flows - the main one and the additional one. The main gas bubble is formed coaxially with laser emission. The gases are fed in front of or behind the focused laser spot. An auxiliary gas bubble is formed by means of an additional nozzle installed at an angle to the cutting surface. The gases are fed to the main and additional gas flows in a certain sequence while maintaining the constant mass or volume flow thereof.

EFFECT: method ensures an increase in productivity of the process of cutting metal structures underwater, an increase in the thickness of the cut metal, and an increase in the safety level during the operations of underwater cutting of metal structures.

1 cl, 3 dwg