Method for producing non-oriented electrical steel sheet

A method for producing a non-oriented electrical steel sheet comprising:

• hot rolling a steel slab having a chemical composition comprising C:
• not more than 0.0050 mass %, Si:
• 1.0 to 6.5 mass %, Mn:
• 0.05 to 2.0 mass %, S:
• not more than 0.0050 mass %, Al:
• not more than 0.01 mass %, N:
• 0.0031 to 0.0050 mass %, Ti:
• not more than 0.0030 mass %, Nb:
• not more than 0.0030 mass %, 0:
• not more than 0.0050 mass % and the remainder being Fe and inevitable impurities,
• subjecting the hot-rolled sheet to a single cold rolling or two or more cold rollings having an intermediate annealing interposed therebetween to have a final sheet thickness, and to a finish annealing,
• wherein a soaking temperature T (° C.) in the finish annealing satisfies the following equation (1):
• (
• 8
• ⁢
• 0
• ⁢
• 0
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• 0
• +
• 400
• ×
• Si
• ⁡
• (
• mass
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• ⁢
• %
• )
• )
• {
• (
• -
• log
• ⁡
• (
• Al
• ⁡
• (
• mass
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• ⁢
• %
• )
• ×
• N
• ⁡
• (
• mass
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• ⁢
• %
• )
• )
• +
• 1.7
• +
• 0.2
• ×
• Si
• ⁡
• (
• mass
• ⁢
• ⁢
• %
• )
• }
• -
• 2
• ⁢
• 7
• ⁢
• 3
• .
• 1
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• 5
• ≤
• T
• ≤
• 1200
• ,
• (
• 1
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• an atmosphere in the finish annealing is a mixed gas containing one or more selected from N2, H2 and a noble gas and having a N2 content of not more than 50 vol % and a dew point of the atmosphere of not higher than −45° C., and
• wherein an amount of N in the steel sheet after the finish annealing is lower than the amount of N in the steel slab by at least 0.0006 mass %.