Effects of Annealing on Magnetic Properties of Electrical Steel and Performances of SRM After Punching

Author

Chao-Chien Chiang ; Knight, Andrew M. ; Min-Fu Hsieh ; Mu-Gong Tsai ; Liu, Bernard Haochih ; In-Gann Chen ; Zwe-Lee Gaing ; Mi-Ching Tsai

Author_Institution

Electr. Motor Technol. Res. Center, Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

50

Issue

11

fYear

2014

fDate

Nov. 2014

Firstpage

1

Lastpage

4

Abstract

This paper compares the microstructure and magnetic properties of punched electrical steel before and after annealing. The effects of this manufacturing process on performance of a switched reluctance motor (SRM) are also investigated. The punching of laminations distorts the grains near the cut edges, and therefore an anneal process is used to recover the damage caused by punching. In this paper, samples are annealed at 750°C for an hour under a N₂ atmosphere. The damaged regions and corresponding recovery after annealing are observed under microscope as the measured core losses are improved up to 37%. The SRM performance is measured and it is found that the torque density can be enhanced when using the annealed electrical steel.

Keywords

annealing; laminations; punching; recovery; reluctance motors; steel; torque; N₂ atmosphere; SRM performances; annealing effects; core losses; cut edges; damaged regions; laminations; magnetic properties; manufacturing process; microstructure; punched electrical steel; switched reluctance motor; temperature 750 degC; time 1 h; torque density; Annealing; Grain size; Magnetic properties; Punching; Reluctance motors; Steel; Torque; Annealing; electric machine; electrical steel; punching; switched reluctance motor (SRM);

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2014.2329708

Filename

6971339