Mechanical characteristics of high-quality laser cutting of steel by fiber and $\mathrm{CO}_2$ lasers

The quality of cutting of low-carbon and stainless steel by beams of fiber and $\mathrm{CO}_2$ lasers with oxygen or nitrogen being used as a process gas is compared. The cut surface roughness for sheets from $3$ to $10$ mm thick is determined. Domains of optimal (in terms of the minimum roughness criterion) application of lasers of various types in the space of dimensionless parameters (Peclet number and dimensionless power) are found. It is demonstrated that the $\mathrm{CO}_2$ laser is more effective for laser-oxygen cutting, while the fiber laser is more beneficial for cutting with the use of a neutral gas.