Method for producing grain-oriented electrical steel sheet

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

• subjecting a steel material to hot rolling to obtain a hot-rolled steel sheet, the steel material having a chemical composition containing by mass %,
• C:
• 0.01% or more and 0.10% or less,
• Si:
• 2.0% or more and 5.0% or less,
• Mn:
• 0.01% or more and 0.50% or less,
• (i) one or both groups of:
• group α:
• Al:
• 0.01% or more and 0.04% or less and N:
• 0.003% or more and 0.010% or less, and group β:
• one or both of S and Se:
• 0.005% or more and 0.100% or less in total, or (ii) Al:
• 0.010% or less, N:
• 0.0060% or less, and one or both of S and Se:
• 0.010% or less in total,
• optionally at least one selected from the group consisting of Ni:
• more than 0% and 1.50% or less, Cr:
• more than 0% and 0.50% or less, Cu:
• more than 0% and 0.50% or less, P:
• more than 0% and 0.50% or less, Sb:
• more than 0% and 0.50% or less, Sn:
• more than 0% and 0.50% or less, Bi:
• more than 0% and 0.50% or less, Mo:
• more than 0% and 0.50% or less, B:
• more than 0 ppm and 25 ppm or less, Nb:
• more than 0% and 0.020% or less, V:
• more than 0% and 0.010% or less, Zr:
• more than 0% and 0.10% or less, Co:
• more than 0% and 0.050% or less, Pb:
• more than 0% and 0.0100% or less, As:
• more than 0% and 0.0200% or less, Zn:
• more than 0% and 0.020% or less, W:
• more than 0% and 0.0100% or less, Ge:
• more than 0% and 0.0050% or less, and Ga:
• more than 0% and 0.0050% or less,
• with the balance being Fe and inevitable impurities;
• subjecting the hot-rolled steel sheet to cold rolling once, or twice or more with intermediate annealing in between, to obtain a cold-rolled steel sheet having a final sheet thickness;
• then subjecting the cold-rolled steel sheet to decarburization annealing;
• then applying an annealing separator to a surface of the steel sheet;
• and
• then subjecting the steel sheet to final annealing, wherein
• the following conditions are satisfied:
• T
• ≤
• -
• 4000
• ×
• A
• +
• 440
• ,
• and
• T
• ≤
• 360
• ,
• wherein A denotes an average C content in mass % in a region ranging from 1/10 to ½ of a sheet thickness below the surface of the steel sheet after subjection to annealing preceding final cold rolling and before subjection to the final cold rolling, and T denotes a time in hours from just after the completion of the annealing preceding the final cold rolling to just before the start of the final cold rolling, and
• after the final cold rolling and before the decarburization annealing, pickling treatment is performed with a treatment solution having an acid with a concentration of 1 mass % or more and 20 mass % or less and an Fe ion content of 2 mass % or more and 15 mass % or less, wherein the acid is selected from the group consisting of phosphoric acid, hydrochloric acid, sulfuric acid, and nitric acid.