US 12,173,377 B2
Grain-oriented electrical steel sheet and method for manufacturing same
Kazutoshi Takeda, Tokyo (JP); Ichiro Tanaka, Tokyo (JP); Tomoya Suenaga, Tokyo (JP); Takashi Kataoka, Tokyo (JP); and Yuki Kunita, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/421,845
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Jan. 16, 2020, PCT No. PCT/JP2020/001157
§ 371(c)(1), (2) Date Jul. 9, 2021,
PCT Pub. No. WO2020/149329, PCT Pub. Date Jul. 23, 2020.
Claims priority of application No. 2019-005239 (JP), filed on Jan. 16, 2019.
Prior Publication US 2022/0098692 A1, Mar. 31, 2022
Int. Cl. C21D 9/46 (2006.01); C21D 8/12 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/60 (2006.01); C23C 22/18 (2006.01); C23C 22/20 (2006.01); C23C 22/74 (2006.01); C23C 28/04 (2006.01); C23G 1/08 (2006.01)
CPC C21D 9/46 (2013.01) [C21D 8/1222 (2013.01); C21D 8/1233 (2013.01); C21D 8/1272 (2013.01); C21D 8/1283 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/60 (2013.01); C23C 22/18 (2013.01); C23C 22/20 (2013.01); C23C 22/74 (2013.01); C23C 28/04 (2013.01); C23G 1/081 (2013.01); C23G 1/083 (2013.01); C23G 1/085 (2013.01); C21D 2201/05 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component, comprising:
a base steel sheet;
a silicon-containing oxide layer provided on the base steel sheet;
an iron-based oxide layer provided on the silicon-containing oxide layer; and
a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components;
wherein the base steel sheet contains, as chemical components, in terms of mass %, 2.5 to 4.5% of Si, 0.05 to 1.00% of Mn, 0% or more and less than 0.05% of Al, 0% or more and less than 0.1% of C, 0% or more and less than 0.05% of N, 0% or more and less than 0.1% of S, 0% or more and less than 0.05% of Se and 0% or more and less than 0.01% of Bi, and the remainder: Fe and impurities,
wherein, when elemental analysis is performed from a surface of the tension-insulation coating in a sheet thickness direction by glow discharge optical emission spectrometry,
(a) in a profile of a Si light emission intensity, there are four or more inflection points;
(b) in the sheet thickness direction, the inflection point of the Si light emission intensity present closest to the base steel sheet side is present within a range of 0.3 to 1.5 μm toward the side of the surface of the tension-insulation coating from a saturation point at which an Fe light emission intensity is a maximum, and
(c) a peak of the Si light emission intensity present closest to the base steel sheet side has a light emission intensity that is 1.3 times or more and 2.0 times or less the Si light emission intensity in the base steel sheet.