Laser Scribing System

LASER SCRIBING SYSTEM FOR GRAIN ORIENTED ELECTRICAL STEEL APPLICATIONS

The Laser Scribing System have been developed with the aim to modify, opportunely, the state and size of the magnetic domains in grain oriented electrical steel (GOES) sheets through the use of laser sources, in order to increase the overall material efficiency by reducing its core losses.

This effect is obtained by irradiating a specific portion of the surface of the GOES sheet with a laser beam whose energy density and whose interaction time are carefully determined and controlled in order to:

  • ensure the reduction of the core losses due to hysteresis cycle, when the material is subject to the action of an oscillating magnetic field with sinusoidal 50 Hz and intensity of the order of Tesla

  • reduce the core losses due to eddy current

  • avoid any damage to the surface coating.

The result is a linear treatment across the width of the magnetic steel sheet and perpendicular to the orientation of the magnetic domains.

The spacing of adjacent parallel lines is also defined and controlled in order to obtain a good compromise between productivity and process result.


FIELDS OF APPLICATION

The Laser Scribing System is designed for special application on Grain Oriented Electrical Steel.

The Laser Scribing System can be integrated:

  • at the end of existing thermoflattering line (on-line system)

  • in a stand alone system with dedicated decoiling and coiling unit (off-line system – laser scribing complex)


LASER SCRIBING SYSTEM MAIN COMPONENTS

  • Supporting structures in welded steel beams for optical benches

  • Optical benches for beam treating, scanning and focussing.

  • Laser beam sources, complete of chillers

  • Magnetic working area for metal sheet during processing

  • CNC and Electro-instrumental components for the supervision of the system

  • Safety protection enclosure and control cabin

  • Fume aspiration and filtration units


LASER SCRIBING SYSTEM PARAMETERS

  • Deposition of the specific energy necessary to ensure the steel damage for domain refinement

  • Continuous and parallel lines, oriented perpendicularly to the GOES sheet transport direction, with width between 40 and 60 microns

  • Spot dimension along the scribing direction, automatically adjustable from 10 to 40 mm, according to optimal process parameters and current line speed. These features permit to avoid coating surface damage

  • Possibility of changing distance between consecutive lines from 4 to 10 mm automatically


LASER SCRIBING SYSTEM MAIN ADVANTAGES

  • Complete control of laser spot shape and size that ensure to work always with the correct value of Interaction Time and Energy Density to reach the optimum reduction of core losses

  • Absence of strip surface defect after laser treatment

  • Fast change of the optical system

  • Hot Redundancy on the laser source modules

  • The Laser Scribing System can be integrated with Coating Integrity Monitoring System for the inspection of the GOES strip surface after scribing treatment, with automatic regulation of scribing parameters.

  • In order to optimize in real time the performance of the laser scribing treatment, the laser scribing system can be integrated with on-line Core Loss Measurement System for the measurement of the GOES strip magnetic property before and after the scribing treatment with automatic regulation of scribing parameters


REMOTE TECHNICAL SERVICE

The Laser Scribing System CNC numerical control is appropriately configured and arranged for a remote technical assistance service.

This service enables assistance to be provided quickly and with the possibility of replacing damaged files, downloading customer files for carrying out analyses, sending updates, etc.

The Technical Service personnel is thus able to carry out an initial analysis of possible problems, also in the perspective of programming the type of intervention with the due precision.


LASER SCRIBING SYSTEM MAIN TECHNICAL SPECIFICATIONS

  • Strip width: up to 1200 mm

  • Strip thickness: starting from 0,10 mm

  • Scribing optical bench: no.2

  • Laser source: Fiber Laser

  • Laser Power: no. 2 x 5000 W (one for each optical bench)

  • Travel speed of GOES sheet: 100 m/min