Title:
METHOD FOR SMELTING HIGH NITROGEN STEEL
Document Type and Number:
Japanese Patent JP2015042777
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To efficiently smelt high nitrogen steel having a nitrogen content of 0.0100 mass% or more and having excellent cleanliness using combination of a converter and a vacuum degassing system.SOLUTION: In a method for smelting high nitrogen steel having a nitrogen content of 0.0100 mass% or more by refluxing molten steel, smelted in a converter and discharged from the converter into a ladle, between the ladle and a vacuum tank of an RH vacuum degasifier by blowing refluxing gas from a dip tube to refine the molten steel, the molten steel is refined after the degree of vacuum in the vacuum tank is lowered to 10 torr (1.333 kPa) or less using argon gas as the refluxing gas, and then the molten steel is refined while the degree of vacuum in the vacuum tank is maintained at a value exceeding 10 torr (1.333 kPa) and nitrogen gas is blown into the vacuum tank.
Inventors:
INOUE NOBORU
MURAI TAKESHI
AGAWA SHINGO
MITSUZONO MASAYUKI
MURAI TAKESHI
AGAWA SHINGO
MITSUZONO MASAYUKI
Application Number:
JP2014144684A
Publication Date:
March 05, 2015
Filing Date:
July 15, 2014
Export Citation:
Assignee:
JFE STEEL CORP
International Classes:
C21C7/00; C21C7/10
Domestic Patent References:
| JPH02225615A | 1990-09-07 | |||
| JPS6428319A | 1989-01-30 | |||
| JPH02225615A | 1990-09-07 |
Attorney, Agent or Firm:
Shigeru Inoue
Woods Kazuhiro
Woods Kazuhiro
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