US 2022/0090246 A1Published application

Method for producing grain oriented electrical steel sheet

AssigneeNippon Steel Corporation

InventorsShinsuke TAKATANI, Yoshiyuki USHIGAMI

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Abstract

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PH2O/PH2 is controlled, an annealing separator applying process where a mass ratio of MgO and MCl in an annealing separator is controlled, a final annealing process where an oxidation degree is controlled when atmosphere includes hydrogen or a dew point is controlled when atmosphere consists of inert gas without hydrogen, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.

Claims7

Dependent claims

A method for producing a grain oriented electrical steel sheet,

the method comprising:
a hot rolling process of hot-rolling a steel piece to obtain a hot rolled steel sheet, the steel piece including, as a chemical composition, by mass %,
0.030 to 0.100% of C,
0.80 to 7.00% of Si,
0.01 to 1.00% of Mn,
0 to 0.060% in total of S and Se,
0.010 to 0.065% of acid soluble Al,
0.004 to 0.012% of N,
0 to 0.30% of Cr,
0 to 0.40% of Cu,
0 to 0.50% of P,
0 to 0.30% of Sn,
0 to 0.30% of Sb,
0 to 1.00% of Ni,
0 to 0.008% of B,
0 to 0.15% of V,
0 to 0.20% of Nb,
0 to 0.10% of Mo,
0 to 0.015% of Ti,
0 to 0.010% of Bi, and
a balance consisting of Fe and impurities;
a cold rolling process of cold-rolling the hot rolled steel sheet to obtain a cold rolled steel sheet;
a decarburization annealing process of decarburization-annealing the cold rolled steel sheet to obtain a decarburization annealed sheet;
an annealing separator applying process of applying and drying an annealing separator including MgO to the decarburization annealed sheet;
a final annealing process of final-annealing the decarburization annealed sheet after applying the annealing separator to obtain a final annealed sheet;
an annealing separator removing process of removing a redundant annealing separator from a surface of the final annealed sheet;
and
an insulation coating forming process of forming an insulation coating on the surface of the final annealed sheet,
wherein, in the decarburization annealing process,
PH2O/PH2 which is an oxidation degree of an atmosphere is 0.18 to 0.80, an annealing temperature is 750 to 900° C., and a holding is 10 to 600 seconds,
wherein, in the annealing separator applying process,
the annealing separator further includes MCl which is at least one selected from chlorides of an alkali metal, an alkaline earth metal, and Bi, and MCl/MgO which is a mass ratio of MgO and MCl is 2 to 40%,
wherein, in the final annealing process,
an oxidation degree is 0.00010 to 0.2 when an atmosphere includes a hydrogen, or a dew point is 0° C. or less when an atmosphere consists of an inert gas without a hydrogen, and
wherein, in the insulation coating forming process,
the insulation coating is formed by applying an insulation coating forming solution which mainly includes a phosphate or a colloidal silica, by baking at 350 to 600° C., and then by heat-treating at 800 to 1000° C.

33 more elements

A method for producing a grain oriented electrical steel sheet,

the method comprising:
a hot rolling process of hot-rolling a steel piece to obtain a hot rolled steel sheet, the steel piece including, as a chemical composition, by mass %,
0.030 to 0.100% of C,
0.80 to 7.00% of Si,
0.01 to 1.00% of Mn,
0 to 0.060% in total of S and Se,
0.010 to 0.065% of acid soluble Al,
0.004 to 0.012% of N,
0 to 0.30% of Cr,
0 to 0.40% of Cu,
0 to 0.50% of P,
0 to 0.30% of Sn,
0 to 0.30% of Sb,
0 to 1.00% of Ni,
0 to 0.008% of B,
0 to 0.15% of V,
0 to 0.20% of Nb,
0 to 0.10% of Mo,
0 to 0.015% of Ti,
0 to 0.010% of Bi, and
a balance comprising Fe and impurities;
a cold rolling process of cold-rolling the hot rolled steel sheet to obtain a cold rolled steel sheet;
a decarburization annealing process of decarburization-annealing the cold rolled steel sheet to obtain a decarburization annealed sheet;
an annealing separator applying process of applying and drying an annealing separator including MgO to the decarburization annealed sheet;
a final annealing process of final-annealing the decarburization annealed sheet after applying the annealing separator to obtain a final annealed sheet;
an annealing separator removing process of removing a redundant annealing separator from a surface of the final annealed sheet;
and
an insulation coating forming process of forming an insulation coating on the surface of the final annealed sheet,
wherein, in the decarburization annealing process,
PH2O/PH2 which is an oxidation degree of an atmosphere is 0.18 to 0.80, an annealing temperature is 750 to 900° C., and a holding is 10 to 600 seconds,
wherein, in the annealing separator applying process,
the annealing separator further includes MCl which is at least one selected from chlorides of an alkali metal, an alkaline earth metal, and Bi, and MCl/MgO which is a mass ratio of MgO and MCl is 2 to 40%,
wherein, in the final annealing process,
an oxidation degree is 0.00010 to 0.2 when an atmosphere includes a hydrogen, or a dew point is 0° C. or less when an atmosphere comprises an inert gas without a hydrogen, and
wherein, in the insulation coating forming process,
the insulation coating is formed by applying an insulation coating forming solution which mainly includes a phosphate or a colloidal silica, by baking at 350 to 600° C., and then by heat-treating at 800 to 1000° C.

33 more elements

Dependencies are inferred from the claim text.

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Abstract

A method for producing a grain oriented electrical steel sheet,

the method comprising:
a hot rolling process of hot-rolling a steel piece to obtain a hot rolled steel sheet, the steel piece including, as a chemical composition, by mass %,
0.030 to 0.100% of C,
0.80 to 7.00% of Si,
0.01 to 1.00% of Mn,
0 to 0.060% in total of S and Se,
0.010 to 0.065% of acid soluble Al,
0.004 to 0.012% of N,
0 to 0.30% of Cr,
0 to 0.40% of Cu,
0 to 0.50% of P,
0 to 0.30% of Sn,
0 to 0.30% of Sb,
0 to 1.00% of Ni,
0 to 0.008% of B,
0 to 0.15% of V,
0 to 0.20% of Nb,
0 to 0.10% of Mo,
0 to 0.015% of Ti,
0 to 0.010% of Bi, and
a balance consisting of Fe and impurities;
a cold rolling process of cold-rolling the hot rolled steel sheet to obtain a cold rolled steel sheet;
a decarburization annealing process of decarburization-annealing the cold rolled steel sheet to obtain a decarburization annealed sheet;
an annealing separator applying process of applying and drying an annealing separator including MgO to the decarburization annealed sheet;
a final annealing process of final-annealing the decarburization annealed sheet after applying the annealing separator to obtain a final annealed sheet;
an annealing separator removing process of removing a redundant annealing separator from a surface of the final annealed sheet;
and
an insulation coating forming process of forming an insulation coating on the surface of the final annealed sheet,
wherein, in the decarburization annealing process,
PH2O/PH2 which is an oxidation degree of an atmosphere is 0.18 to 0.80, an annealing temperature is 750 to 900° C., and a holding is 10 to 600 seconds,
wherein, in the annealing separator applying process,
the annealing separator further includes MCl which is at least one selected from chlorides of an alkali metal, an alkaline earth metal, and Bi, and MCl/MgO which is a mass ratio of MgO and MCl is 2 to 40%,
wherein, in the final annealing process,
an oxidation degree is 0.00010 to 0.2 when an atmosphere includes a hydrogen, or a dew point is 0° C. or less when an atmosphere consists of an inert gas without a hydrogen, and
wherein, in the insulation coating forming process,
the insulation coating is formed by applying an insulation coating forming solution which mainly includes a phosphate or a colloidal silica, by baking at 350 to 600° C., and then by heat-treating at 800 to 1000° C.

33 more elements