Modeling of laser-induced combustion of iron in oxygen during gas-laser cutting

Abstract

A physical and mathematical model is proposed for cyclic combustion of iron in an oxygen stream during oxygen gas-laser cutting of sheet metal. The combustion front is driven by focused laser radiation and heterogeneous iron oxidation in oxygen. The burning rate is limited by the rate of oxygen supply from the gas phase to the metal surface, and the motion of the interface is determined by the local temperature mode. Three-dimensional numerical modeling revealed striated structures on the metal surface whose linear dimensions depended on velocity of the laser beam and oxygen flow parameters. The modeling results explain the mechanism of striation formation during oxygen gas-laser cutting of low-carbon steel and agree qualitatively with experimental data.