Method for producing grain-oriented electrical steel sheet

A method for producing grain-oriented electrical steel sheet comprising

• a process of heating and hot rolling a slab containing, by mass %, C:
• 0.01% or more and 0.10% or less, Si:
• 2.5% or more and 4.5% or less, Mn:
• 0.01% or more and 0.50% or less, a total of one or more of S, Se, and Te:
• 0.001% or more and 0.050% or less, acid soluble Al:
• more than 0% and 0.05% or less, and N:
• more than 0% and 0.015% or less and having a balance of Fe and impurities to obtain a hot rolled steel sheet or annealing the hot rolled steel sheet to obtain a hot rolled annealed sheet,
• wherein the slab optionally contains, in place of part of the Fe, one or more of Cu:
• 1.0% or less, Sn:
• 1.0% or less, Ni:
• 1.0% or less, Cr:
• 1.0% or less, Sb:
• 1.0% or less, and Bi:
• 1.0% or less,
• wherein the grain-oriented electrical steel sheet includes one or more of MnS, MnSe, and MnTe,
• a process of cold rolling the hot rolled steel sheet or the hot rolled annealed sheet to obtain a cold rolled steel sheet,
• a process of annealing the cold rolled steel sheet for primary recrystallization to obtain a primary recrystallized annealed sheet,
• a process of coating a surface of the primary recrystallized annealed sheet with an annealing separator including MgO, then finish annealing it to obtain a finish annealed sheet, and
• a process of coating the finish annealed sheet with an insulation coating, then annealing it for flattening,
• at least one steel sheet among the hot rolled steel sheet, the hot rolled annealed sheet, the cold rolled steel sheet, and the primary recrystallized annealed sheet being treated by leveling and treated by contact with a solution, wherein the solution penetrates to a depth of 10 to 500 μm from the surface of the steel sheet,
• in the leveling treatment, the number of bending operations of the steel sheet being two or more, a bending angle being 10 degrees or more and 90 degrees or less, and a bending radius being 10 mm or more and 200 mm or less,
• the solution containing one or more of Cu, Hg, Ag, Pb, Cd, Co, Zn, and Ni, having a total concentration of 0.00001% or more and 1.0000% or less, having a pH of −1.5 or more and less than 7, and having a solution temperature of 15° C. or more and 100° C. or less, the time during which the steel sheet is dipped in the solution being 5 seconds or more and 200 seconds or less,
• wherein at least a portion of Mn in the MnS, MnSe, and MnTe in the grain-oriented electrical steel sheet is substituted for one or more of Cu, Hg, Ag, Pb, Cd, Co, Zn, and Ni, through contact with the solution at a depth of 10 to 500 μm from the surface of the steel sheet.