Non-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-9637812-B2
Application number	US-201314051688-A
Country	US
Kind code	B2
Filing date	Oct 11, 2013
Priority date	Sep 3, 2009
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A non-oriented electrical steel sheet contains 2.8 mass % or more and 4.0 mass % or less of Si, 0.2 mass % or more and 3.0 mass % or less of Al, and 0.02 mass % or more and 0.2 mass % or less of P. The non-oriented electrical steel sheet contains further contains 0.5 mass % or more in total of at least one kinds selected from a group consisting of 4.0 mass % or less of Ni and 2.0 mass % or less of Mn. A C content is 0.05 mass % or less, a N content is 0.01 mass % or less, an average grain diameter is 15 μm or less, and a <111> axial density is 6 or larger.

First claim

The invention claimed is:

1. A method for manufacturing a non-oriented electrical steel sheet comprising:
hot-rolling a slab to obtain a hot-rolled steel sheet, wherein a finish rolling temperature in the hot-rolling is 850° C. or below;
after the hot-rolling, cold-rolling the hot-rolled steel sheet to obtain a cold-rolled steel sheet; and
after the cold-rolling, finish-annealing the cold-rolled steel sheet for 25 seconds or shorter at 750° C. or below,
wherein
the slab comprises:
Si: 2.8 mass % or more and 4.0 mass % or less;
Al: 0.2 mass % or more and 3.0 mass % or less;
P: 0.02 mass % or more and 0.2 mass % or less; and
0.5 mass % or more in total of at least one element selected from the group consisting of 4.0 mass % or less of Ni and 2.0 mass % or less of Mn,
a C content in the slab is 0.05 mass % or less,
a N content in the slab is 0.01 mass % or less,
a balance of the slab is composed of Fe and inevitable impurity.

2. The method according to claim 1 , wherein the hot-rolled steel sheet is not annealed prior to the cold-rolling, and intermediate annealing is not performed during the cold-rolling.

3. The method according to claim 2 , wherein the hot-rolled steel sheet is coiled at 650° C. or below after the hot-rolling.

4. The method according to claim 1 , wherein the hot-rolled steel sheet is coiled at 650° C. or below after the hot-rolling.

5. A method for manufacturing a non-oriented electrical steel sheet comprising:
hot-rolling a slab to obtain a hot-rolled steel sheet, wherein a finish rolling temperature in the hot-rolling is 850° C. or below;
after the hot-rolling, cold-rolling the hot-rolled steel sheet to obtain a cold-rolled steel sheet; and
after the cold-rolling, finish-annealing the cold-rolled steel sheet for 30 seconds or shorter at 740° C. or below,
wherein
the slab comprises:
Si: 2.8 mass % or more and 4.0 mass % or less;
Al: 0.2 mass % or more and 3.0 mass % or less;
P: 0.02 mass % or more and 0.2 mass % or less; and
0.5 mass % or more in total of at least one element selected from the group consisting of 4.0 mass % or less of Ni and 2.0 mass % or less of Mn,
a C content in the slab is 0.05 mass % or less,
a N content in the slab is 0.01 mass % or less,
a balance of the slab is composed of Fe and inevitable impurity.

6. The method according to claim 5 , wherein a time period of the finish-annealing is 25 seconds or shorter.

7. The method according to claim 6 , wherein the hot-rolled steel sheet is not annealed prior to the cold-rolling, and intermediate annealing is not performed during the cold-rolling.

8. The method according to claim 7 , wherein the hot-rolled steel sheet is coiled at 650° C. or below after the hot-rolling.

9. The method according to claim 6 , wherein the hot-rolled steel sheet is coiled at 650° C. or below after the hot-rolling.

10. The method according to claim 5 , wherein the hot-rolled steel sheet is not annealed prior to the cold-rolling, and intermediate annealing is not performed during the cold-rolling.

11. The method according to claim 10 , wherein the hot-rolled steel sheet is coiled at 650° C. or below after the hot-rolling.

12. The method according to claim 5 , wherein the hot-rolled steel sheet is coiled at 650° C. or below after the hot-rolling.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Kubota Takeshi

Classifications

• C22C38/08

  containing nickel {(C22C38/105 takes precedence)} · CPC title

• C22C38/004

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

• C22C38/12 Primary

  containing tungsten, tantalum, molybdenum, vanadium, or niobium · CPC title

• C21D8/1233 Primary

  Cold rolling · CPC title

• C22C38/04

  containing manganese · CPC title