| 摘要 |
PROBLEM TO BE SOLVED: To effect highly versatile laser cutting that is applicable to an existing thick steel plate as it is, without imparting a special property to it, by emitting a descaling laser beam to the cutting part of the thick steel plate, removing a scale layer on the plate surface, irradiating the scale-removed part with a cutting laser beam and cutting the thick steel plate. SOLUTION: First, a descaling laser beam 7 is converged on its converging part 13, vaporizing and removing scales 3; then, a cutting laser beam 5 is converged on its converging part 11, performing cutting on a thick steel plate 1. The width of the scale 3 removed by the descaling laser 7 is desirably about 3 times as wide as the cutting width. While an assist gas is supplied using and assist gas nozzle 9, it is desirable that the gas contains O2 gas as the main component. The assist gas is supplied so as to flow from the front to the rear in the machining direction. |
