Method for producing non-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-2018355454-A1
Application number	US-201615781920-A
Country	US
Kind code	A1
Filing date	Oct 11, 2016
Priority date	Dec 9, 2015
Publication date	Dec 13, 2018
Grant date	—

Abstract

A method for producing a non-oriented electrical steel sheet by hot rolling a steel slab containing C: not more than 0.0050%, Si: not more than 5.0%, Mn: not more than 3.0%, P: not more than 0.2%, S: not more than 0.005%, Al: not more than 3.0%, N: not more than 0.005%, Ni: not more than 3.0%, Cr: not more than 5.0%, Ti: not more than 0.005%, and subjecting the sheet to a cold rolling and a finish annealing, wherein the heating in the finish annealing is conducted in two stages of performing an induction heating and subsequently a radiation heating and the induction heating is conducted up to not lower than 720° C. at an average heating rate of not less than 50° C./sec between 600° C. and 700° C. and a time from the end of the induction heating to the start of the radiation heating is not more than 8 seconds.

First claim

1 . A method for producing a non-oriented electrical steel sheet by hot rolling a steel slab having a chemical composition comprising C: not more than 0.0050 mass %, Si: not more than 5.0 mass %, Mn: not more than 3.0 mass %, P: not more than 0.2 mass %, S: not more than 0.005 mass %, Al: not more than 3.0 mass %, N: not more than 0.005 mass %, Ni: not more than 3.0 mass %, Cr: not more than 5.0 mass %, Ti: not more than 0.005 mass %, Nb: not more than 0.005 mass %, B: not more than 0.005 mass %, O: not more than 0.005 mass % and the remainder being Fe and inevitable impurities and subjecting the sheet to a cold rolling after a hot band annealing or without a hot band annealing and further to a finish annealing, characterized in that the heating in the finish annealing is conducted in two stages of performing an induction heating and subsequently a radiation heating, and the induction heating is conducted up to not lower than 720° C. at an average heating rate of not less than 50° C./sec between 600° C. and 700° C. and a time from the end of the induction heating to the start of the radiation heating is set to not more than 8 seconds.

2 . The method for producing a non-oriented electrical steel sheet according to claim 1 , wherein the steel slab contains one or two selected from Sn: 0.005-0.20 mass % and Sb: 0.005-0.20 mass % in addition to the above chemical composition.

3 . The method for producing a non-oriented electrical steel sheet according to claim 1 , wherein the steel slab contains one or two or more selected from Ca: 0.0001-0.010 mass %, Mg: 0.0001-0.010 mass % and REM: 0.0001-0.010 mass % in addition to the above chemical composition.

4 . The method for producing a non-oriented electrical steel sheet according to claim 2 , wherein the steel slab contains one or two or more selected from Ca: 0.0001-0.010 mass %, Mg: 0.0001-0.010 mass % and REM: 0.0001-0.010 mass % in addition to the above chemical composition.

5 . The method for producing a non-oriented electrical steel sheet according to claim 1 , wherein a ferrite grain size of a steel sheet structure before a final cold rolling in the cold rolling is set to not more than 70 μm.

6 . The method for producing a non-oriented electrical steel sheet according to claim 2 , wherein a ferrite grain size of a steel sheet structure before a final cold rolling in the cold rolling is set to not more than 70 μm.

7 . The method for producing a non-oriented electrical steel sheet according to claim 3 , wherein a ferrite grain size of a steel sheet structure before a final cold rolling in the cold rolling is set to not more than 70 μm.

8 . The method for producing a non-oriented electrical steel sheet according to claim 4 , wherein a ferrite grain size of a steel sheet structure before a final cold rolling in the cold rolling is set to not more than 70 μm.

Assignees

• Jfe Steel Corp

Inventors

• Okubo Tomoyuki
• Zaizen Yoshiaki
• Oda Yoshihiko

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C22C38/06

  containing aluminium · CPC title

• C21D6/005

  containing Mn · CPC title

• C21D9/46 Primary

  for sheet metals · CPC title

• C22C38/005

  containing rare earths, i.e. Sc, Y, Lanthanides · CPC title