公开(公告)号：US20250157708A1

公开(公告)日：2025-05-15

申请号：US18838920

申请日：2023-04-04

Applicant: NIPPON STEEL CORPORATION

Inventor： Masato YASUDA ,  Hideyuki HAMAMURA ,  Nobusato MORISHIGE ,  Shinji YAMAMOTO ,  Kimihiko SUGIYAMA

IPC: H01F1/18 ,  B23K26/364 ,  C21D6/00 ,  C21D8/12 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06

Abstract: The present invention has as its object to provide grain-oriented electrical steel sheet better improved in core loss in control of magnetic domains for forming laser grooves in cold rolled steel sheet. The present invention provides grain-oriented electrical steel sheet meeting the following requirements for achieving the object:
That is, it provides grain-oriented electrical steel sheet comprising a base material steel sheet having a plurality of grooves on the surface of the steel sheet and a glass coating on the surface of the base material steel sheet, in which grain-oriented electrical steel sheet, an absolute value of an angle θ formed by a direction perpendicular to a rolling direction and a sheet thickness direction of the base material steel sheet and a longitudinal direction of the grooves is 0 to 40°, a width W of the grooves is 20 μm to 300 μm, a depth D of the grooves is 10 μm to 40 μm, and a pitch P of the grooves in the rolling direction is 1.0 mm to 30 mm, and, when a thickness of the glass coating at flat parts of the surface of the base material steel sheet is t1, a glass coating thickness of deepest parts of the grooves in the recessed parts of the grooves is t2, and a glass coating thickness of side parts of the grooves is t3, the relationship of formula (1) is satisfied: (t2+t3)/2≥t1  formula (1)

公开(公告)号：US20250154631A1

公开(公告)日：2025-05-15

申请号：US18838639

申请日：2023-04-04

Applicant: NIPPON STEEL CORPORATION

Inventor： Masato YASUDA ,  Hideyuki HAMAMURA ,  Nobusato MORISHIGE ,  Masaru TAKAHASHI ,  Kimihiko SUGIYAMA

IPC: C22C38/02 ,  C21D6/00 ,  C21D8/12 ,  C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06

Abstract: The present invention has as its object to provide grain-oriented electrical steel sheet better improved in core loss in control of magnetic domains for forming laser grooves in cold rolled steel sheet. The present invention provides grain-oriented electrical steel sheet meeting the following requirements for achieving the object:
That is, it provides grain-oriented electrical steel sheet comprising a base material steel sheet having a plurality of grooves on its surface and a glass coating on the surface of the base material steel sheet, in which grain-oriented electrical steel sheet, an absolute value of an angle θ formed by a direction perpendicular to a rolling direction and a sheet thickness direction of the base material steel sheet and a longitudinal direction of the grooves is 0 to 40°, a width W of the grooves is 20 μm to 300 μm, a depth D of the grooves is 10 μm to 40 μm, and a pitch P of the grooves in the rolling direction is 1.0 mm to 30.0 mm, and, at an inside of the glass coating directly under surfaces of the recessed parts of the grooves, one or more fine grains of a long axis of 1 μm or more and 20 μm or less are present in a cross-section perpendicular to the longitudinal direction of the grooves.

公开(公告)号：US20210074456A1

公开(公告)日：2021-03-11

申请号：US16961286

申请日：2019-02-08

Applicant: NIPPON STEEL CORPORATION

Inventor： Satoshi ARAI ,  Hideyuki HAMAMURA ,  Shunsuke OKUMURA ,  Kimihiko SUGIYAMA

IPC: H01F1/147 ,  C22C38/60 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B23K26/364

Abstract: A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves. An average protrusion height of the surface protrusion extending along a longitudinal direction of the groove is more than 5 μm and not more than 10 μm. When the surface protrusion is viewed in a cross section including the longitudinal direction of the groove and a normal direction of the steel sheet surface, the surface protrusion includes specific portions each having a height of 50% or more with respect to a height of each peak point appearing on a profile line of the surface protrusion. In the longitudinal direction of the groove, the total length of the specific portions is a length of 30% or more with respect to an overall length of the surface protrusion.