Patent ID: 11962184
Assignee: JFE STEEL CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  H  B  Y | IPC B  C  H

Claim 14:
15. A method for producing a motor core comprising
taking out a rotor core material and a stator core material at the same time from a non-oriented electrical steel sheet produced by the method according to claim 1,
laminating the rotor core material to form a rotor core, and
laminating the stator core material followed by a stress-relief annealing to form a stator core, characterized in that
the steel sheet constituting the stator core is subjected to the stress-relief annealing so that N1, N2 and t satisfy the following equation (2):

(t×N2)/{(t/10)×N1}≥5.0  (2)

and that an iron loss W10/400 (W/kg) satisfies the following equation (3) in relation to the sheet thickness t (mm):

W10/400≤8+20×t  (3),, where N1 (mass %) is a content of nitrogen present as AlN (N as AlN) in a layer from a one-side surface to 1/20 of a sheet thickness and N2 (mass %) is a content of nitrogen present as AlN in a full sheet thickness (N as AlN) and t (mm) is a sheet thickness of the steel sheet.