Loading patent…
AssigneeJfe Steel Corporation
InventorsHideto KAMBARA, Ken SAKAI, Shinichi KITAMURA, Toru NAKASHIMA
Estimating the term…
An annealing facility in which a steel sheet after cold rolling is sequentially threaded through an annealing furnace having at least a first region, a second region, and a third region to continuously undergo finish annealing. Each of the regions of the annealing furnace is independently controllable in terms of the gas composition and the dew point of the atmosphere. The second region is composed of a heating zone, a soaking zone, and a cooling zone all having atmospheric temperatures of 900° C. or higher, with an atmospheric gas controlled to have a nitrogen content of 30 vol % or less and a dew point of −40° C. or lower. Further, an electrical steel sheet, preferably a non-oriented electrical steel sheet with low iron loss is produced by performing finish annealing using this annealing facility.
A finish annealing facility for producing an electrical steel sheet in which a steel sheet after cold rolling is sequentially threaded through an annealing furnace having at least a first region, a second region, and a third region so as to continuously undergo finish annealing,
A non-oriented electrical steel sheet, wherein, when a content of nitrogen present as AlN in a layer of 1/20 of a sheet thickness of the steel sheet from one side surface is Ns (mass %), a content of nitrogen present as AlN across the entire sheet thickness is Nt (mass %), and the sheet thickness of the steel sheet is t (mm), Ns, Nt, and t satisfy the following Formula (1):
Dependencies are inferred from the claim text.