Patent ID: 7976644

Claim:
A method of production of grain-oriented electrical steel sheet comprising the steps of: heating a silicon steel slab containing, by mass %, Si: 0.8 to 7%, C: 0.085% or less, acid soluble Al: 0.01 to 0.065%, and N: 0.012% or less at a temperature of 1280° C. or less, then hot rolling the heated slab into a hot rolled steel strip, annealing the hot rolled steel strip, then cold rolling the annealed steel strip once or several times with intermediate annealing to a final steel strip thickness, decarburization annealing the cold rolled steel strip, then coating an annealing separator, and applying final annealing, wherein the decarburization annealed steel strip is treated to increase nitrogen in the decarburization annealed steel strip from the decarburization annealing to the start of secondary recrystallization in the final annealing, characterized by: performing the annealing of the hot rolled steel strip by heating to a predetermined temperature of 1000° to 1150° C. to cause recrystallization, then annealing the recrystallized steel strip at a temperature of 850° to 1100° C. to provide a grain structure having a lamellar spacing of 20 μm or more in the annealed recrystallized steel strip, and heating the cold-rolled steel strip during decarburization annealing in a heating process consisting of only induction heating at a heating rate of 40° C./s or more in a steel strip temperature range of 550° C. to 720° C.