Non-oriented electrical steel sheet and hot rolled steel sheet thereof

Patent metadata

Field	Value
Publication number	US-10006109-B2
Application number	US-201414909940-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Aug 20, 2013
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss at not only a commercial frequency but also a high frequency zone, which has a chemical composition including C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: not more than 0.0050 mass, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass % and Ca: 0.001-0.01 mass % and the remainder being Fe and inevitable impurities and a compositional ratio of CaO in oxide-based inclusions existing in a steel sheet of not less than 0.4 and/or a compositional ratio of Al 2 O 3 of not less than 0.3, and a hot rolled steel sheet used as a raw steel material thereof.

First claim

The invention claimed is:

1. A non-oriented electrical steel sheet having a chemical composition consisting of C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: 0.0001 mass % to not more than 0.0050 mass %, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass %, Ca: 0.001-0.01 mass %, optionally Sn: 0.01 mass % to not more than 0.1 mass %, optionally Sb: 0.01 mass % to not more than 0.1 mass %, and the remainder being Fe and inevitable impurities,
wherein, in oxide based inclusions in a finished form of the steel sheet, a mass % ratio as defined by equation (1) is not less than 0.4, and/or a mass % ratio as defined by equation (2) is not less than 0.3,
CaO/(SiO 2 +Al 2 O 3 +CaO)  (1),

Al 2 O 3 /(SiO 2 +Al 2 O 3 +CaO)  (2).

2. A hot rolled steel sheet used as a raw material for the non-oriented electrical steel sheet of claim 1 , the hot rolled steel sheet having a chemical composition consisting of C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: 0.0001 mass % to not more than 0.0050 mass %, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass %, Ca: 0.001-0.01 mass %, optionally Sn: 0.01 mass % to not more than 0.1 mass %, optionally Sb: 0.01 mass % to not more than 0.1 mass %, and the remainder being Fe and inevitable impurities,
wherein, in oxide based inclusions in the hot rolled steel sheet, a mass % ratio as defined by equation (1) is not less than 0.4, and/or a mass % ratio as defined by equation (2) is not less than 0.3,
CaO/(SiO 2 +Al 2 O 3 +CaO)  (1),

Al 2 O 3 /(SiO 2 +Al 2 O 3 +CaO)  (2).

3. The non-oriented electrical steel sheet according to claim 1 , wherein the steel sheet has a magnetic flux density (B 50 ) that is not less than 1.69 T.

4. The non-oriented electrical steel sheet according to claim 1 , wherein the steel sheet has a magnetic flux density (B 50 ) that is not less than 1.70 T.

Assignees

• Jfe Steel Corp

Inventors

• Nakanishi Tadashi
• Koseki Shinji
• Oda Yoshihiko
• Toda Hiroaki

Classifications

• H01F1/342

  Oxides (H01F1/36 and H01F1/38 take precedence) · CPC title

• C22C38/004

  Very low carbon steels, i.e. having a carbon content of less than 0,01% · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• C21D8/1233

  Cold rolling · CPC title

• B21B3/02

  Rolling special iron alloys {, e.g. stainless steel} · CPC title