Title:
DECARBURIZATION END-POINT DETERMINATION METHOD, DECARBURIZATION END-POINT DETERMINATION DEVICE, SECONDARY REFINING OPERATION METHOD FOR STEEL MAKING, AND METHOD FOR PRODUCING MOLTEN STEEL
Document Type and Number:
WIPO Patent Application WO/2021/157541
Kind Code:
A1
Abstract:
A decarburization end-point determination method according to the present invention comprises: an estimation step for estimating the carbon concentration and the oxygen concentration in a molten steel during a vacuum decarburization treatment and the carbon dioxide gas concentration in a discharged gas in a vacuum tank by using measurement values of the carbon concentration and the oxygen concentration in the molten steel before the start of the vacuum decarburization treatment, a measurement value of the internal pressure in the vacuum tank and a model formula for the vacuum decarburization treatment; and a determination step for correcting a parameter included in the model formula in such a manner that at least one difference selected from the difference between an estimate value and a measurement value of the oxygen concentration in the molten steel at the timing of the measurement of the oxygen concentration in the molten steel during the vacuum decarburization treatment and the difference between an estimate value and a measurement value of the carbon dioxide gas in the discharged gas at the timing of the measurement of the carbon dioxide gas in the discharged gas during the vacuum decarburization treatment can be reduced, then estimating the carbon concentration in the molten steel using the model formula in which the parameter has been corrected, and then determining a timing at which the estimate value reaches a target value as the end-point of the vacuum decarburization treatment.
Inventors:
KUYAMA SHUJI (JP)
OGASAHARA TOMOYOSHI (JP)
NAKAI YOSHIE (JP)
MIZOBATA KEISUKE (JP)
ISHIDA TOMOHARU (JP)
KIKUCHI MASAMICHI (JP)
OGASAHARA TOMOYOSHI (JP)
NAKAI YOSHIE (JP)
MIZOBATA KEISUKE (JP)
ISHIDA TOMOHARU (JP)
KIKUCHI MASAMICHI (JP)
Application Number:
PCT/JP2021/003616
Publication Date:
August 12, 2021
Filing Date:
February 02, 2021
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21C7/00; C21C7/10
Domestic Patent References:
| WO2003004707A1 | 2003-01-16 |
Foreign References:
| JPH09202913A | 1997-08-05 | |||
| JP2015101742A | 2015-06-04 | |||
| JP2016141875A | 2016-08-08 | |||
| JP2008266751A | 2008-11-06 | |||
| JP2007169717A | 2007-07-05 | |||
| JP2015101742A | 2015-06-04 | |||
| JP2007169717A | 2007-07-05 | |||
| JP2006104521A | 2006-04-20 |
Other References:
See also references of EP 4101937A4
Attorney, Agent or Firm:
SAKAI INTERNATIONAL PATENT OFFICE (JP)
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