公开(公告)号：EP0815268B1

公开(公告)日：2000-11-22

申请号：EP96927908.2

申请日：1996-08-26

申请人： NIPPON STEEL CORPORATION

发明人： SAKURAI, Koichi ,  SHIBUYA, Tatsuru ,  WAKABAYASHI, Hisamoto ,  WAKI, Kouichi ,  SUGIYAMA, Seiji ,  NAGAI, Kazunori

IPC分类号： C21D9/573 ,  C21D1/613

CPC分类号： C21D9/573 ,  C21D1/613 ,  C21D9/561

公开(公告)号：EP0815268A1

公开(公告)日：1998-01-07

申请号：EP96927908.0

申请日：1996-08-26

申请人： NIPPON STEEL CORPORATION

发明人： SAKURAI, Koichi ,  SHIBUYA, Tatsuru ,  WAKABAYASHI, Hisamoto ,  WAKI, Kouichi ,  SUGIYAMA, Seiji ,  NAGAI, Kazunori

IPC分类号： C21D1 ,  C21D9

CPC分类号： C21D9/573 ,  C21D1/613 ,  C21D9/561

摘要： In a method of continuously annealing steel strip comprising a heating step (A), a soaking step (B), a primary cooling step (C) including a rapid cooling step at least in a second half thereof, an overaging step (D), and a final cooling step (E), inert atmosphere gas containing H2 gas in the concentration of 30 - 60 % is employed as cooling gas for use in the rapid cooling step, the blowoff temperature of the cooling gas is 30 - 150 °C, and the blowoff speed of the cooling gas is 100 - 150 m/sec. The primary cooling method in continuously annealing steel strip provides the primary cooling step (C) including the rapid cooling step which can be carried out with a high efficiency and a low cost.