Manufacturing method of non-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-9579701-B2
Application number	US-201113813862-A
Country	US
Kind code	B2
Filing date	Jul 29, 2011
Priority date	Aug 4, 2010
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A steel having a predetermined composition is hot-rolled so as to form a steel strip, the steel strip is subjected to first cold-rolling, the steel strip is subjected to intermediate annealing, the steel strip is subjected to second cold-rolling, and the steel strip is subjected to finish annealing. A finish temperature in the hot-rolling is 900° C. or less, annealing is not performed between the hot-rolling and the first cold-rolling, and a rolling reduction in the second cold-rolling is not less than 40% nor more than 85%.

First claim

The invention claimed is:

1. A manufacturing method of a non-oriented electrical steel sheet, comprising:
performing hot-rolling of a steel material so as to form a steel strip, the steel material containing, in mass %:
Si: not less than 0.1% nor more than 4.0%;
Al: not less than 0.1% nor more than 3.0%; and
Mn: not less than 0.1% nor more than 2.0%;
a C content being 0.003% or less, and
a balance being composed of Fe and inevitable impurity elements;

next, performing first cold-rolling of the steel strip, wherein a rolling reduction in the first cold-rolling is not less than 31.4% nor more than approximately 40%;
next, performing intermediate annealing of the steel strip;
next, performing second cold-rolling of the steel strip; and
next, performing finish annealing of the steel strip at a temperature of not less than 950° C. nor more than 970° C. so as to cause recrystallization in which crystal grains in { 110 }<001> orientation grow, wherein
a finish temperature in the hot-rolling is 900° C. or less,
the first cold-rolling is started without performing annealing after the hot-rolling; and
a rolling reduction in the second cold-rolling is not less than 40% nor more than 85%.

2. The manufacturing method of a non-oriented electrical steel sheet according to claim 1 , wherein the steel material contains, in mass %, one or two selected from a group consisting of Sn: not less than 0.02% nor more than 0.40% and Cu: not less than 0.1% nor more than 1.0%.

3. The manufacturing method of a non-oriented electrical steel sheet according to claim 1 , wherein the steel material contains, in mass %, P: 0.15% or less.

4. The manufacturing method of a non-oriented electrical steel sheet according to claim 2 , wherein the steel material contains, in mass %, P: 0.15% or less.

5. The manufacturing method of a non-oriented electrical steel sheet according to claim 1 , wherein the steel material contains, in mass %, Cr: not less than 0.2% nor more than 10.0%.

6. The manufacturing method of a non-oriented electrical steel sheet according to claim 2 , wherein the steel material contains, in mass %, Cr: not less than 0.2% nor more than 10.0%.

7. The manufacturing method of a non-oriented electrical steel sheet according to claim 3 , wherein the steel material contains, in mass %, Cr: not less than 0.2% nor more than 10.0%.

8. The manufacturing method of a non-oriented electrical steel sheet according to claim 4 , wherein the steel material contains, in mass %, Cr: not less than 0.2% nor more than 10.0%.

9. The manufacturing method of a non-oriented electrical steel sheet according to claim 1 , wherein a rolling reduction in the first cold-rolling is not less than 31.4% nor more than 38.9%.

Assignees

• Kubota Takeshi
• Fujikura Masahiro
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Kubota Takeshi
• Fujikura Masahiro

Classifications

• C22C38/008

  containing tin · CPC title

• C21D8/1266

  between cold rolling steps · CPC title

• C21D9/46

  for sheet metals · CPC title

• C22C38/18

  containing chromium · CPC title

• C21D2201/05

  Grain orientation · CPC title