Title:
鋼帯の連続焼鈍方法、溶融亜鉛めっき方法
Document Type and Number:
Japanese Patent JP5071551
Kind Code:
B2
Abstract:
Formation of oxides of elements susceptible to oxidation such as Si and Mn contained in the steel of steel strips due to concentration of the elements susceptible to oxidation in the surfaces of the steel strips during annealing is suppressed. A vertical annealing furnace including a heating zone, a soaking zone, and a cooling zone is used in which a portion of gas in the furnace is introduced into a refiner that is disposed outside of the furnace to decrease the dew point of the gas and the gas whose dew point has been decreased is returned into the furnace. A connection part between the soaking zone and the cooling zone is disposed in an upper portion of the furnace. Suction ports through which the gas in the furnace is sucked so as to be introduced into the refiner are disposed in a portion of the cooling zone near the connection part between the soaking zone and the cooling zone and in an upper portion of the soaking zone. Feed ports through which the gas from the refiner is returned to the furnace are disposed in the connection part between the soaking zone and the cooling zone and in a lower portion of the soaking zone. A gas suction rate Qo1 in the portion of the cooling zone near the connection part between the soaking zone and the cooling zone, a gas suction rate Qo2 in the upper portion of the soaking zone, a gas feed rate Qi1 in the connection part between the soaking zone and the cooling zone, a gas feed rate Qi2 in the lower portion of the soaking zone, a supply rate Qf1 of the atmosphere gas into the cooling zone and a zone subsequent to the cooling zone, a supply rate Qf2 of the atmosphere gas into the soaking zone, an internal volume Vs of the soaking zone, and an average furnace temperature Ts of the soaking zone satisfy relationships including 0.3 x Qf1 < Qo1.
Inventors:
Hideyuki Takahashi
Nobuyuki Sato
Kazuki Nakazato
Masato Iri
Nobuyuki Sato
Kazuki Nakazato
Masato Iri
Application Number:
JP2010281406A
Publication Date:
November 14, 2012
Filing Date:
December 17, 2010
Export Citation:
Assignee:
jfe Steel Corporation
International Classes:
C21D9/56; C21D1/74; C21D1/76; C23C2/06; C23C2/28; C23C2/40; F27D7/06
Domestic Patent References:
| JP7138652A | ||||
| JP8109417A | ||||
| JP2005171294A | ||||
| JP10046237A |
Attorney, Agent or Firm:
Shigeru Inoue
Kazuhiro Mori
Kazuhiro Mori