Parameterization of hybrid laser-assisted oxygen cutting of thick steel plates

Specific features of hybrid laser-assisted oxygen cutting of mild steel sheets are studied theoretically and experimentally. The shape and geometrical size of a supersonic confuser-diffuser nozzle are demonstrated to play an important role in the formation of oxygen cutting jet. The numerical solution of three-dimensional Navier–Stokes equations reveals a pseudoshock phenomenon in the gas flow in a narrow channel, which is the reason for elevated roughness in the lower part of the cut under certain conditions. A method of the analytical calculation of effective cutting parameters, which depend on the material thickness, nozzle geometry, and range of oxygen pressure, is proposed. Engineering recommendations are formulated, which are used to perform full-scale experiments on an automated laser technological complex in cutting steel sheets upto 30–50 mm thick.

► Gas jet propagation in laser-assisted oxygen cutting is examined numerically.
► Pseudo-shock effect disturbing cutting process is found.
► The method of the analytical prediction of the effective cutting parameters is proposed.
► Conventional laser and hybrid laser-assisted oxygen cutting methods are supplementary.