Grain-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-2018043474-A1
Application number	US-201615549784-A
Country	US
Kind code	A1
Filing date	Apr 19, 2016
Priority date	Apr 20, 2015
Publication date	Feb 15, 2018
Grant date	—

Abstract

Provided is a grain-oriented electrical steel sheet including a steel sheet having a steel sheet surface in which a groove, which extends in a direction intersecting a rolling direction and of which a groove depth direction matches a sheet thickness direction, is formed. When an average value of a groove depth in a sheet thickness direction at a central portion of the groove in a longitudinal groove direction is set as an average groove depth D, a straight line, which connects a first point at which a groove depth in the sheet thickness direction becomes 0.05×D and a second point at which the groove depth becomes 0.50×D, at an inclined portion of the groove is set as a groove end straight line, an angle made by the steel sheet surface and the groove end straight line is set as a first angle θ, and an average value of a groove-width-direction length, which is a length of a line segment connecting two points at which a groove depth in the sheet thickness direction in a contour of the groove on the groove-width-direction cross-section becomes 0.05×D, is set as an average groove width W, an aspect ratio A obtained by dividing the average groove depth D by the average groove width W, and the first angle θ satisfy the following Expression (1).
θ<−21× A +77  (1)

First claim

1 . A grain-oriented electrical steel sheet, comprising:
a steel sheet having a steel sheet surface in which a groove, which extends in a direction intersecting a rolling direction and of which a groove depth direction matches a sheet thickness direction, is formed, wherein the groove includes an inclined portion that is inclined from the steel sheet surface to a bottom portion of the groove at a groove end in a longitudinal groove direction that is a direction in which the groove extends, when an average value of a depth of the groove in the sheet thickness direction from a height of the steel sheet surface at a central portion in the longitudinal groove direction is set as an average groove depth D in a unit of μm, a straight line, which connects a first point at which the depth of the groove in the sheet thickness direction from the height of the steel sheet surface becomes 0.05×D, and a second point at which the depth of the groove in the sheet thickness direction from the height of the steel sheet surface becomes 0.50×D, at the inclined portion is set as a groove end straight line, an angle made by the steel sheet surface and the groove end straight line is set as a first angle θ in a unit of °, and in a case where the groove is seen on a groove-width-direction cross-section perpendicular to the longitudinal groove direction at the central portion of the groove, an average value of a groove-width-direction length, which is a length of a line segment connecting two points at which a depth of the groove in the sheet thickness direction from the height of the steel sheet surface in a contour of the groove on the groove-width-direction cross-section becomes 0.05×D, is set as an average groove width W of the groove in a unit of μm, an aspect ratio A obtained by dividing the average groove depth D by the average groove width W, and the first angle θ satisfy the following Expression (1),
θ<−21× A+ 77  (1).

2 . The grain-oriented electrical steel sheet according to claim 1 , wherein the aspect ratio A and the first angle θ satisfy the following Expression (2),
θ<32× A 2 −55× A+ 73  (2).

3 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein when the average groove depth D is 15 μm to 30 μm, the first angle θ, the average groove depth D, and the average groove width W satisfy the following Expression (3),
θ≦0.12× W− 0.45× D+ 57.39  (3).

4 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein when the average groove width W is 30 m to 100 μm, the first angle θ, the average groove depth D, and the average groove width W satisfy the following Expression (4),
θ≦−0.37× D+ 0.12× W+ 55.39  (4).

5 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein in the steel sheet, a grain size of a crystal grain that is in contact with the groove is 5 μm or greater.

6 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein the average groove depth D is 10 μm to 50 μm.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Hamamura Hideyuki
• Sakai Tatsuhiko
• Takahashi Fumiaki
• Mogi Hisashi
• Okumura Shunsuke
• Imai Hirofumi

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title

• C22C38/04

  containing manganese · CPC title

• C22C38/02

  containing silicon · CPC title

• C21D6/005

  containing Mn · CPC title