METHOD FOR PRODUCING HOT-DIP GALVANIZED STEEL SHEET AND CONTINUOUS HOT-DIP GALVANIZING APPARATUS

WIPO Patent Application WO/2019/123953

A1

The present invention provides a method for producing a hot-dip galvanized steel sheet which can ensure high plating adhesion and satisfactory plating appearance when hot-dip galvanizing is performed on a steel sheet having a Si content of 0.2% by mass or more. A steel plate P is conveyed inside an annealing furnace through a heating zone, a soaking zone and a cooling zone in this order to anneal the steel plate, and then the steel plate discharged from the cooling zone is subjected to hot-dip galvanization. In the path where the steel plate moves upward when supplying humidified gas into the soaking zone 12, the humidified gas is supplied from first humidified gas supply ports 40A to 40E provided at positions overlapping with the steel plate in the path, as viewed from the side of the soaking zone, these positions being 1.0 m to 5.0 m higher than the center of a lower hearth roll 54. In the path where the steel plate moves downward, the humidified gas is supplied from second humidified gas supply ports 42A to 42E provided at positions overlapping with the steel plate in the path, as viewed from the side of the soaking zone, these positions being 1.0 m to 5.0 m lower than the center of an upper hearth roll 52.

TAKEDA GENTARO (JP)
TAKAHASHI HIDEYUKI (JP)
IWATA TETSUYA (JP)
SAWAMURA KOJI (JP)

PCT/JP2018/042900

June 27, 2019

November 20, 2018

Click for automatic bibliography generation  

JFE STEEL CORP (JP)

C23C2/02; C21D9/56; C23C2/06; C23C2/28; C23C2/40; C22C38/00; C22C38/04

WO2015068369A1	2015-05-14
WO2007043273A1	2007-04-19

JP2016125131A	2016-07-11
JP2010202959A	2010-09-16
JP2016017193A	2016-02-01
JP2010185101A	2010-08-26

See also references of EP 3730662A4

SUGIMURA Kenji (JP)

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