公开(公告)号：EP0130695A3

公开(公告)日：1987-04-15

申请号：EP84303651

申请日：1984-05-31

申请人： MITSUI HIGH-TEC, INC. ,  NIPPON STEEL CORPORATION

发明人： Koshiishi, Hiromichi ,  Eguchi, Shigeki Nippon Steel Corp. Yawata Works ,  Sakamoto, Hisahumi Nippon Steel Corp. Yawata Works ,  Kuramasu, Hisayoshi Nippon Steel Corp.

IPC分类号： C21D08/12 ,  C21D01/30 ,  C21D01/42 ,  H01F01/16

CPC分类号： C21D9/0018 ,  C21D1/42 ,  C21D9/46 ,  H01F1/16 ,  Y02P10/253

摘要： The present invention relates to a method for annealing a core blank (1) of a transformer or the like so as to relieve the stress generated in the electrical steel sheet sections due to blanking. The present invention is an improvement over the conventional resistance or gas-heating method in the light of heating efficiency and time and is characterized by induction-heating (21, 22) a core blank (1) at a power input range of from 0.5 to 3 kW/kg of the core blank (1). This range attains a small variation in the shape of a core blank (1) due to induction-heating (21, 22).