Laser cutting method

A method for laser fusion cutting a workpiece, which comprises the steps of:

• directing a laser beam and a cutting gas at a cutting gas pressure at a workpiece surface by means of a convergent cutting nozzle, the convergent cutting nozzle having a nozzle end face on a workpiece side;
• setting a laser power to be at least 6 KW;
• setting a distance between the nozzle end face and the workpiece surface during the laser fusion cutting to be 2 to 8 mm;
• setting a diameter of a nozzle channel of the convergent cutting nozzle at the nozzle end face on the workpiece side to be 1.5 to 4 mm;
• setting the cutting gas pressure before emergence from the convergent cutting nozzle to be 15 to 30 bar;
• advancing the convergent cutting nozzle towards at least one puncture point on the workpiece surface at an advancement speed;
• at a predetermined displacement distance upstream of the puncture point, reducing the advancement speed to a puncture speed lower than the advancement speed, such that the convergent cutting nozzle reaches the at least one puncture point at the puncture speed;
• puncturing the workpiece surface with the laser beam at the at least one puncture point.