US 11,866,812 B2
Grain oriented electrical steel sheet, forming method for insulation coating of grain oriented electrical steel sheet, and producing method for grain oriented electrical steel sheet
Ichiro Tanaka, Tokyo (JP); Takashi Kataoka, Tokyo (JP); Kazutoshi Takeda, Tokyo (JP); Masamitsu Kubota, Tokyo (JP); and Hirotoshi Tada, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/427,535
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Feb. 7, 2020, PCT No. PCT/JP2020/004865
§ 371(c)(1), (2) Date Jul. 30, 2021,
PCT Pub. No. WO2020/162608, PCT Pub. Date Aug. 13, 2020.
Claims priority of application No. 2019-021284 (JP), filed on Feb. 8, 2019.
Prior Publication US 2022/0090242 A1, Mar. 24, 2022
Int. Cl. C22C 38/20 (2006.01); C22C 38/34 (2006.01); C22C 38/00 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C21D 9/46 (2006.01); C21D 8/02 (2006.01); C21D 3/04 (2006.01); C23G 1/08 (2006.01); C22C 38/60 (2006.01)
CPC C22C 38/20 (2013.01) [C21D 3/04 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/008 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/34 (2013.01); C22C 38/60 (2013.01); C23G 1/081 (2013.01); C21D 2201/05 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A grain oriented electrical steel sheet without a forsterite film characterized in that
the grain oriented electrical steel sheet comprises:
a base steel sheet;
an oxide layer arranged in contact with the base steel sheet; and
a tension-insulation coating arranged in contact with the oxide layer,
wherein the base steel sheet includes, as a chemical composition, by mass %,
2.5 to 4.0% of Si,
0.05 to 1.00% of Mn,
0.02 to 0.50% of Cr,
0 to 0.01% of C,
0 to 0.005% of St-Se,
0 to 0.01% of sol.Al,
0 to 0,005% of N,
0 to 0.03% of Bi,
0 to 0.03% of Te,
0 to 0.03% of Pb,
0 to 0.50% of Sb,
0 to 0.50% of Sn,
0 to 1.0% of Cu, and
a balance consisting of Fe and impurities,
the tension-insulation coating is a phosphate-silica mixed tension-insulation coating with an average thickness of 1 to 3 μm,
when a glow discharge spectroscopy is conducted in a region from a surface of the tension-insulation coating to an inside of the base steel sheet; when a sputtering time at which a Fe emission intensity becomes 0.5 times as compared with a saturation value thereof on a depth profile is referred to as Fe0.5 in unit of seconds, and when a sputtering time at which a Fe emission intensity becomes 0.05 times as compared with the saturation value on the depth profile is referred to as Fe0.05 in unit of seconds, the Fe0.5 and the Fe0.05 satisfy (Fe0.5−Fe0.05)/Fe0.5≥0.35,
when a sputtering time at which a Fe emission intensity becomes the saturation value on the depth profile is referred to as Fesat in unit of seconds, and when a sputtering time at which a Cr emission intensity becomes a maximal value on the depth profile is referred to as Crmax in unit of seconds, a maximal point of a Cr emission intensity at which a Cr emission intensity at the Crmax becomes 0.08 to 0.25 times as compared with a Fe emission intensity at the Cram is included between the Fe0.05 and the Fesat on the depth profile, and
a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.