Title:
METHOD OF SMELTING HIGHLY CLEAN STEEL WITH EXTREMELY LOW SULFUR CONTENT
Document Type and Number:
WIPO Patent Application WO/2007/116939
Kind Code:
A1
Abstract:
A method of smelting a highly clean steel with extremely low sulfur content, involving
treating of molten steel through the following steps (1) to (4). Step (1): a CaO-based
flux is added to the molten steel within a ladle under atmospheric pressure. Step
(2): an agitation gas is blown into the molten steel within the ladle after the
step (1) to carry out agitation, and simultaneously an oxidizing gas is fed into
the molten steel, and any formed oxides are mixed with the CaO-based flux. Step
(3): the feeding of the oxidizing gas is terminated, and the agitation gas is blown
into the molten steel within the ladle to thereby carry out desulfurization and
foreign matter elimination. Step (4): in the treating of the molten steel after
the step (3) by means of RH vacuum degasifier, an oxidizing gas is fed into the vessel
of the RH vacuum degasifier to thereby raise the temperature of the molten steel.
In this smelting method, optionally, Al addition is effected in either the step
(1) or step (2) and the step (4) is omitted. In this smelting method, as temperature-raising
heating for the molten steel and controlling of slag component formulation and
further agitating operation of the molten steel and slag can be appropriately
performed, desulfurization and cleanliness enhancement can be simultaneously
promoted to thereby realize efficient stable smelting of highly clean steel
with extremely low sulfur content.
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Inventors:
TAKEUCHI, Shingo (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
武内 慎吾 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
武内 慎吾 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
Application Number:
JP2007/057665
Publication Date:
October 18, 2007
Filing Date:
April 05, 2007
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES, LTD. (5-33, Kitahama 4-chome Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
住友金属工業株式会社 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 Osaka, 5410041, JP)
TAKEUCHI, Shingo (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
住友金属工業株式会社 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 Osaka, 5410041, JP)
TAKEUCHI, Shingo (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
International Classes:
C21C7/064; C21C7/04; C21C7/06; C21C7/072; C21C7/076; C21C7/10; C21C7/064; C21C7/04; C21C7/06; C21C7/072; C21C7/10
Attorney, Agent or Firm:
MORI, Michio (M. MORI PATENT OFFICE, Amagasaki Building17-23, Higashinaniwa-cho 5-chom, Amagasaki-shi Hyogo, 660-0892, JP)
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