Title:
METHOD FOR PRODUCING GALVANNEALED STEEL SHEET, AND CONTINUOUS HOT DIP GALVANIZING APPARATUS
Document Type and Number:
WIPO Patent Application WO/2018/198493
Kind Code:
A1
Abstract:
The present invention provides a method for producing a galvannealed steel sheet, by which high plating adhesion and a good plating appearance can be attained in a case where a steel sheet having a Si content of 0.2 mass% or more is hot dip galvanized, and which can suppress the occurrence of pick-up defects by rapidly switching the dew point in a soaking zone atmosphere, even in cases where a steel sheet having a Si content of less than 0.2 mass% is subsequently continuously hot dip galvanized. In the present invention, in cases where a steel sheet that passes through a soaking zone is a type of steel containing 0.2 mass% or more of Si, both a dry gas and a moist gas are supplied to the soaking zone, the latter part of the soaking zone is determined on the basis of the sheet passing speed V and the target temperature T on the outlet side of the soaking zone, and the moist gas is supplied only from a moist gas supply port, from among a plurality of moist gas supply ports, that is positioned in the latter part of the soaking zone.
Inventors:
TAKEDA GENTARO (JP)
MAKIMIZU YOICHI (JP)
SUZUKI YOSHIKAZU (JP)
HIMEI YOSHIMASA (JP)
TAKAHASHI HIDEYUKI (JP)
MAKIMIZU YOICHI (JP)
SUZUKI YOSHIKAZU (JP)
HIMEI YOSHIMASA (JP)
TAKAHASHI HIDEYUKI (JP)
Application Number:
PCT/JP2018/005809
Publication Date:
November 01, 2018
Filing Date:
February 19, 2018
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C23C2/02; C21D9/56; C23C2/06; C23C2/28; C23C2/40
Foreign References:
| JP2016180136A | 2016-10-13 | |||
| JP2013245362A | 2013-12-09 | |||
| JP2016017192A | 2016-02-01 |
Other References:
See also references of EP 3617339A4
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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