JPWO2022250159A5

JPWO2022250159A5 -

Info

Publication number: JPWO2022250159A5
Application number: JP2022573141A
Authority: JP
Filing date: 2022-05-27
Publication date: 2023-05-02
Anticipated expiration: 2042-05-27

Claims

in % by mass,
C: 0.01% or more and 0.10% or less,
Si: 2.0% or more and 4.0% or less,
Mn: 0.01% or more and 0.30% or less,
Ti: 0.010% or less,
Contains Al: 0.010% or less and N: 0.0050% or less, further contains one or two of S and Se in a total of 0.005% or more and 0.10% or less, and the balance is A steel slab having a chemical composition consisting of Fe and unavoidable impurities is slab-heated to 1300 ° C. or higher and hot-rolled to form a hot-rolled sheet,
Then, the hot-rolled sheet is cold-rolled one or more times with or without hot-rolled sheet annealing, optionally with intermediate annealing, to obtain a cold-rolled sheet;
Then, the cold-rolled sheet is subjected to decarburization annealing to obtain a decarburization-annealed sheet,
Next, in the method for producing a grain-oriented electrical steel sheet, an annealing separator is applied to the surface of the decarburized annealed sheet, and then finish annealing is performed to obtain a grain-oriented electrical steel sheet,
The total rolling reduction of the finish rolling in the hot rolling is 83% or more, and the total rolling reduction of the first cold rolling is 50% or more,
A method for producing a grain-oriented electrical steel sheet, wherein a compound containing Si is attached to the surface of the cold-rolled steel sheet before the decarburization annealing in an amount of 0.1 mg/m ² or more and 7.0 mg/m ^{2 or} less per side in terms of Si weight.

The decarburization annealing is divided into pre-stage annealing and post-stage annealing,
In the pre-annealing, the atmosphere oxidation P(H ₂ O)/P(H ₂ ) is 0.3 or more and 0.7 or less,
2. The method for producing a grain-oriented electrical steel sheet according to claim 1, wherein said post-annealing is performed in an annealing atmosphere in which the ratio of atmospheric oxidation P( _H2O )/P( _H2 ) is 0.005 or more and 0.2 or less.

In the hot rolling, after the slab is heated, the steel slab is subjected to one pass or more of rough rolling at 1100° C. or more and 1300° C. or less, followed by two passes or more of finish rolling at 800° C. or more and 1100° C. or less. The taking temperature is 400° C. or higher and 750° C. or lower,
In the hot-rolled sheet annealing, after holding the hot-rolled sheet at 800° C. or more and 1250° C. or less for 5 seconds or more,
Cooling with an average cooling rate of 5 ° C./s or more and 100 ° C./s or less from 800 ° C. to 350 ° C.,
The total rolling reduction of the cold rolling is 50% or more and 92% or less, and the total rolling reduction of the cold rolling each time is 50% or more and 92% or less,
In the intermediate annealing, after holding in a temperature range of 800° C. or higher and 1250° C. or lower for 5 seconds or longer, cooling is performed at an average cooling rate of 5° C./s or higher and 100° C./s or lower from 800° C. to 350° C.,
In the decarburization annealing, the cold-rolled sheet is held at 750° C. or more and 950° C. or less for 10 seconds or more in an atmosphere containing H ₂ and N ₂ ,
Before the finish annealing, the annealing separator containing MgO is applied to the surface of the decarburized annealed sheet in an amount of 2.5 g/m ² or more per side,
2. The decarburization-annealed sheet is held at 1050° C. or higher and 1300° C. or lower for 3 hours or more under conditions in which the atmosphere in at least part of the temperature range of 800° C. or higher contains _H2 in the final annealing, or 3. The method for producing a grain-oriented electrical steel sheet according to 2.

3. The method for producing a grain-oriented electrical steel sheet according to claim 1, wherein the component composition further contains at least one component selected from Groups A to C below.
Group A: % by mass or ppm by mass,
Ni: 0% or more and 1.50% or less,
Cr: 0% or more and 0.50% or less,
Cu: 0% or more and 0.50% or less,
P: 0% or more and 0.50% or less,
Sb: 0% or more and 0.50% or less,
Sn: 0% or more and 0.50% or less,
Bi: 0% or more and 0.50% or less,
Mo: 0% or more and 0.50% or less,
B: 0 ppm or more and 25 ppm or less,
Nb: 0% or more and 0.020% or less,
V: 0% or more and 0.010% or less and Zr: 1 or 2 or more selected from the group consisting of 0% or more and 0.10% or less .
Group B: % by mass,
Co: 0% or more and 0.050% or less and
Pb: 1 or 2 selected from the group consisting of 0% or more and 0.0100% or less.
Group C: % by mass,
As: 0% or more and 0.0200% or less,
Zn: 0% or more and 0.020% or less,
W: 0% or more and 0.0100% or less
Ge: 0% or more and 0.0050% or less and
Ga: One or more selected from the group consisting of 0% or more and 0.0050% or less.

4. The method for producing a grain-oriented electrical steel sheet according to claim 3, wherein the component composition further contains at least one component selected from Groups A to C below.
Group A: % by mass or ppm by mass,
Ni: 0% or more and 1.50% or less,
Cr: 0% or more and 0.50% or less,
Cu: 0% or more and 0.50% or less,
P: 0% or more and 0.50% or less,
Sb: 0% or more and 0.50% or less,
Sn: 0% or more and 0.50% or less,
Bi: 0% or more and 0.50% or less,
Mo: 0% or more and 0.50% or less,
B: 0 ppm or more and 25 ppm or less,
Nb: 0% or more and 0.020% or less,
V: 0% or more and 0.010% or less and
Zr: One or more selected from the group consisting of 0% or more and 0.10% or less.
Group B: % by mass,
Co: 0% or more and 0.050% or less and
Pb: 1 or 2 selected from the group consisting of 0% or more and 0.0100% or less.
Group C: % by mass,
As: 0% or more and 0.0200% or less,
Zn: 0% or more and 0.020% or less,
W: 0% or more and 0.0100% or less
Ge: 0% or more and 0.0050% or less and
Ga: One or more selected from the group consisting of 0% or more and 0.0050% or less.