Title:
PROCESS FOR PRODUCING STEEL HAVING HIGH CLEANLINESS
Document Type and Number:
WIPO Patent Application WO/2021/256161
Kind Code:
A1
Abstract:
The present invention provides a production method for steel having high cleanliness and excellent rolling fatigue life, said production method more adequately suppressing the generation of MgO–Al2O3-based inclusions. A ladle refining step in this invention comprises: a first period in which the agitation force for molten steel is a first value; and a second period in which the agitation force for the molten steel is a second value that is smaller than the first value. The addition of Al to the molten steel occurs either at the start of or during the second period. The time t (mins) from the addition of Al in the second period until the end of the ladle refining step fulfills the relationship in (1). V indicates the volume (m3) of the molten steel, A indicates the molten steel/slag reaction interface area (m2), (2) indicates the agitation force (W/t) for the molten steel during the second period, aO indicates the oxygen activity (–) in the molten steel after Al has been added during the second period, and aMgO indicates the MgO activity (–) in the slag at the start of the second period.
Inventors:
HARADA AKIFUMI (JP)
MATSUI AKITOSHI (JP)
NAKAI YOSHIE (JP)
KONDO HIROKAZU (JP)
MATSUI AKITOSHI (JP)
NAKAI YOSHIE (JP)
KONDO HIROKAZU (JP)
Application Number:
PCT/JP2021/019248
Publication Date:
December 23, 2021
Filing Date:
May 20, 2021
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21C7/00; C21C7/06; C21C7/072; C21C7/10
Foreign References:
| JP2016222953A | 2016-12-28 | |||
| JPH10298631A | 1998-11-10 |
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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