Laser treatment of a workpiece by a laser beam, by lowering contours with laser beam, generating two crack columns on the surface of the workpiece, and forming the grain-oriented portions with a grain orientation

摘要

The method comprises lowering contours with a laser beam (3) that lies on a surface facing towards the laser beam by non-grain-oriented portions of a workpiece (1) with a feed of the laser beam at a speed of 300 m/min, where a crack gap (4) is produced along the contours, generating two crack columns on the surface of the workpiece to reduce magnetic losses by refining the magnetic domain structure in the structure of the workpiece or by forming grain-oriented portions on the surface of the workpiece, and forming the grain-oriented portions with a grain orientation. The method comprises lowering contours with a laser beam (3) that lies on a surface facing towards the laser beam by non-grain-oriented portions of a workpiece (1) with a feed of the laser beam at a speed of 300 m/min, where a crack gap (4) is produced along the contours, generating two crack columns on the surface of the workpiece to reduce magnetic losses by refining the magnetic domain structure in the structure of the workpiece or by forming grain-oriented portions on the surface of the workpiece, and forming the grain-oriented portions with a grain orientation parallel or perpendicular to the magnetic flux lines of a magnetic circuit of the workpiece. The laser beam consists of a non-grain-oriented electrical steel material. A laser beam power, a focus diameter and a feed of the laser beam are chosen such that the laser beam of a pressure expansion in a sphere of influence is carried out by evaporating electrical steel material for ejecting 60% of the electrical steel material melted by the laser beam from the crack columns and for forming a layer of electrical steel material having an amorphous structure of a thickness 1-20 mu m on a cleavage surface of the respective crack gap. A beam power of 2-30 watts, a focus diameter of 100-600 mu m and a feed rate of the laser beam of 300-15.000 m/min are adjusted. A ratio of the focus diameter/electrical steel material thickness of 1-100 and/or a material removal having a thickness is adjusted to less than 150 mu m. A finally annealed electrical steel material is used. The portions of the workpiece before and/or after the laser treatment are provided with a coating application. An independent claim is included for a workpiece.