Title:
METHOD FOR PRODUCING GRAIN-ORIENTED ELECTROMAGNETIC STEEL SHEET, AND MgO FOR ANNEALING SEPARATING AGENT
Document Type and Number:
Japanese Patent JP2014156619
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing grain-oriented electromagnetic steel sheet that can effectively remove nitrogen and produce a grain-oriented electromagnetic steel sheet having a good magnetic property in an industrially stable manner, even though it is a method for producing grain-oriented electromagnetic steel sheet in which nitrogen is added to the steel sheet before secondary recrystallization for the purpose of forming silicon nitride.SOLUTION: In a method for producing grain-oriented electromagnetic steel sheet comprising a series of processes including: subjecting a steel slab whose N is controlled within a range of [acid soluble Al (sol. Al) mass ppm/26.98]×14.00≤N≤80 mass ppm and the remainder is controlled within a predetermined composition, to hot rolling, without re-heating or after re-heating, to yield a hot rolled sheet; followed by annealing and rolling to yield a cold rolled sheet having a final sheet thickness; subjecting the same to nitriding treatment such that the increased nitrogen amount became 50 to 1000 mass ppm until before secondary recrystallization annealing; followed by coating the same with an annealing separating agent; and controlling the residence time during the interval between 300°C and 800°C in the temperature rising process of secondary recrystallization annealing within 5 hours or more and 150 hours or less, an annealing separating agent that contains MgO by 50 mass% or more and that satisfies the condition that the citric acid activity of the MgO is 60 seconds≤CAA30≤90 seconds as well as 150 seconds≤CAA70≤250 seconds, is used as the annealing separating agent.
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Inventors:
TERAJIMA TAKASHI
ARAGAKI YUKIHIRO
ARAGAKI YUKIHIRO
Application Number:
JP2013027035A
Publication Date:
August 28, 2014
Filing Date:
February 14, 2013
Export Citation:
Assignee:
JFE STEEL CORP
International Classes:
C21D8/12; C22C38/00; C22C38/60; C23C22/00; H01F1/16
Domestic Patent References:
| JP2001107147A | 2001-04-17 | |||
| JPS5745472B2 | 1982-09-28 | |||
| JP3456415B2 | 2003-10-14 | |||
| JP2002220623A | 2002-08-09 | |||
| JP2000273550A | 2000-10-03 | |||
| JPH11158558A | 1999-06-15 |
Attorney, Agent or Firm:
Kenji Sugimura
Kengo Yoshida
Kengo Yoshida
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