Linear groove formation method and linear groove formation device

Patent metadata

Field	Value
Publication number	US-2018147663-A1
Application number	US-201615575920-A
Country	US
Kind code	A1
Filing date	Jul 6, 2016
Priority date	Jul 28, 2015
Publication date	May 31, 2018
Grant date	—

Abstract

A linear groove formation method of forming linear grooves in a steel sheet surface using etching can form linear grooves of a uniform shape while suppressing a decrease in magnetic property of a grain-oriented electrical steel sheet caused by laser irradiation for resist removal. A linear groove formation method includes: coating a surface of a grain-oriented electrical steel sheet with a resist; performing a laser scan cyclically in a rolling direction of the grain-oriented electrical steel sheet, the laser scan being applying a laser while scanning the laser in a direction crossing the rolling direction to remove the resist in a portion irradiated with the laser; and etching the grain-oriented electrical steel sheet in each portion in which the resist is removed, to form a linear groove. A coating thickness of the resist is 0.5 μm to 10 μm, and a power of the laser is 1500 W or more.

First claim

1 . A linear groove formation method comprising:
coating a surface of a grain-oriented electrical steel sheet with a resist; performing a laser scan cyclically in a rolling direction of the grain-oriented electrical steel sheet, the laser scan being applying a laser while scanning the laser in a direction crossing the rolling direction of the grain-oriented electrical steel sheet to remove the resist in a portion irradiated with the laser; and etching the grain-oriented electrical steel sheet in each portion in which the resist is removed, to form a linear groove, wherein a coating thickness of the resist is 0.5 μm to 10 μm, and a power of the laser is 1500 W or more.

2 . The linear groove formation method according to claim 1 ,
wherein the laser scan is performed using one to five laser irradiation devices, a scanning time t per one laser scan is 2.5 msec or more, and a ratio Y of a steel sheet scanning time t′ during which the applied laser is actually scanned on the surface of the grain-oriented electrical steel sheet in one laser scan to the scanning time t per one laser scan is 0.8 or less, where Y=t′/t.

3 . The linear groove formation method according to claim 2 ,
wherein the laser scan is performed using one to three laser irradiation devices, a beam diameter of the laser in a direction orthogonal to a scanning direction of the laser is more than 0.1 mm and 0.4 mm or less, and a ratio of a major axis length to a minor axis length of the laser is 1.25 or less.

4 . The linear groove formation method according to claim 2 ,
wherein the laser scan is performed using four or five laser irradiation devices, a beam diameter of the laser in a direction orthogonal to a scanning direction of the laser is 0.03 mm or more and 0.1 mm or less, and a ratio of a major axis length to a minor axis length of the laser is 1.1 or less.

5 . A linear groove formation device comprising:
a deliverer that delivers a coiled grain-oriented electrical steel sheet; a welder that joints coils to each other; a resist coater that coats a surface of the grain-oriented electrical steel sheet with a resist; a dryer that dries the resist applied on the surface of the grain-oriented electrical steel sheet; a laser irradiator that irradiates, with a laser, the surface of the grain-oriented electrical steel sheet coated with the resist, to remove the resist partially; an etcher that etches the grain-oriented electrical steel sheet in each portion in which the resist is removed; a resist remover that removes the resist from the surface of the grain-oriented electrical steel sheet; a cutter that cuts the grain-oriented electrical steel sheet; and a coiler that coils the grain-oriented electrical steel sheet, arranged in the stated order, and the linear groove formation device further comprising a looper that keeps a sheet passing rate in the laser irradiator constant.

Assignees

• Jfe Steel Corp

Inventors

• Takajo Shigehiro
• Uesaka Masanori

Classifications

• B23K26/073

  Shaping the laser spot · CPC title

• H01F1/16

  in the form of sheets (H01F1/147 takes precedence) · CPC title

• C25F3/06

  of iron or steel · CPC title

• C21D10/005

  by laser shock processing · CPC title

• C23F1/28

  for etching iron group metals · CPC title