Method for forming linear groove and method for manufacturing grain-oriented electrical steel sheet

Abstract

Provided is a method for forming a linear groove, which forms a linear groove in the surface of a steel sheet such as a grain-oriented electrical steel sheet, and which is excellent in terms of iron loss reduction effect and magnetic flux density. The linear groove forming method comprises: a corrosion-resistant protective film forming step of forming a corrosion-resistant protective film on the surface of a steel sheet; a laser irradiation step in which laser scanning is periodically performed in the rolling direction of the steel sheet, the laser scanning being performed in a direction intersecting the rolling direction of the steel sheet while irradiating the steel sheet with laser light to remove the resist film in the portion irradiated with the laser light; and an etching step in which the resist protective film is continuously removed in the plate width direction using two or more beams of laser light irradiated from each of two or more laser light irradiation devices arranged side by side in the plate width direction of the steel plate, and when the spot diameter of the laser light is set to be [phi], the spot diameter of the laser light is set to be [phi], and the spot diameter of the laser light is set to be [phi]. The laser centers of two laser beams respectively irradiated from two laser irradiation devices adjacent to each other in the plate width direction are offset in a range of 0.05 [phi] or more and 0.95 [phi] or less in a direction orthogonal to the scanning direction of the laser beams.

Description

technical field [0001] The present invention relates to a method for forming linear grooves and a method for manufacturing a grain-oriented electrical steel sheet. Background technique [0002] Grain-oriented electrical steel sheets are used as materials for transformer cores. The iron loss of the grain-oriented electrical steel sheet has a great influence on the energy loss of the transformer. In recent years, reduction of energy loss in transformers has been strongly demanded from the viewpoint of energy saving and environmental regulation. Since the iron loss of a transformer is affected by the iron loss of a grain-oriented electrical steel sheet as a raw material, it is very important to develop a grain-oriented electrical steel sheet with a low iron loss. [0003] The iron loss of the grain-oriented electrical steel sheet is separated into hysteresis loss and eddy current loss. As a method of improving hysteresis loss, a method of orienting (110)[001] orientation cal...

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Problems solved by technology

For example, it is known that when a resist pattern is formed by gravure offset printing as in Patent Document 2, due to variations in the viscosity of the resist ink or the shape of the gravure unit, the spread pattern of the resist ink changes, resulting in white spots. , Defects such as slot interruption, magnetic properties deteriorate

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