Laser Cutting Steels

Abstract

The laser cutting industry is dominated by the profiling of steel sheet of both mild and stainless grades. The cutting process is achieved by a combination of laser heating and the chemical reaction of iron with oxygen. This oxidation reaction is exothermic (heat generating) and acts as a secondary energy source which helps to accelerate the cutting process. Basically, the steel is locally heated by the focused laser beam to a temperature at which the iron will ignite in the oxygen jet acting coaxially with the beam. Stainless steel is cut slightly less effectively than mild steel because the presence of chromium oxide in the cut zone tends to seal off the melt from the incident oxygen jet. For this reason the mechanics of cutting are different for mild and stainless steels and it is convenient to discuss them separately.