EP0126560A2 - Casting nozzle and method of casting using same - Google Patents
Casting nozzle and method of casting using same Download PDFInfo
- Publication number
- EP0126560A2 EP0126560A2 EP84302838A EP84302838A EP0126560A2 EP 0126560 A2 EP0126560 A2 EP 0126560A2 EP 84302838 A EP84302838 A EP 84302838A EP 84302838 A EP84302838 A EP 84302838A EP 0126560 A2 EP0126560 A2 EP 0126560A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- nozzle
- casting
- carbon
- composition
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/50—Pouring-nozzles
- B22D41/52—Manufacturing or repairing thereof
- B22D41/54—Manufacturing or repairing thereof characterised by the materials used therefor
Definitions
- the present invention relates to a nozzle for casting ultra low carbon steel.
- an ultra low carbon steel has been proposed which contains less than 15 ppm carbon.
- a need has arisen for a casting nozzle suitable for casting ultra low carbon steels by the continuous casting process.
- alumina-graphite nozzles which are used for casting conventional, carbon-containing steels, are used for casting ultra-low carbon steels. carbon pickup becomes apparent either as the nozzle is worn away by the molten steel or through decarburization of the nozzle itself.
- conventional alumina-graphite nozzles are not suitable for use with ultra low carbon steels.
- Fused silica nozzles do not contain carbon. However, these nozzles are susceptible to wear, especially by high manganese steel.
- a casting nozzle formed of a material comprising 70 to 98 weight % of a refractory material other than carbon or graphite, and 2 to 30 weight % of boron nitride.
- the refractory material is selected from sintered or electrically fused magnesium, non-stabilized or semi-stabilized zirconia, alpha-alumina, beta-alumina, mullite, sillimanite, clay materials, fused silica, Si 3 N 4 , B 4 C and SiC.
- an inorganic bonding agent is mixed with the composition, e.g in an amount of from 5 to 20 weight % of the composition.
- an inorganic bonding agent e.g. clay (e.g. bentonite), waterglass, aluminium phosphate etc.
- the nozzle of the present invention is made by moulding the present composition followed by sintering in a reducing atmosphere.
- boron nitride If more than 30% boron nitride is used, then the nozzle is easily oxidized to B 2 0 3 and wear of the nozzle is increased. If less than 2% boron nitride is used, the desirable characteristics of boron nitride, i.e. chemical inertness and high thermal conductivity are not shown and thermal shock spalling is increased.
- compositions and bonding agents mentioned above are added with an appropriate amount of water and kneaded in a kneader for 40 minutes.
- the mixtures are dried in a drying furnace at 80°C for 12 hours so that the residual water content goes down to 1% to 3%, and thereafter crushed by a crusher to particles smaller than lmm.
- Rubber molds are filled with the thus prepared materials and molded under a molding pressure of 1,000 kg/cm 2 in order to form immersion nozzles of predetermined shapes.
- the molding products are then sintered in a tunnel furnace whose ceiling temperature is 1250°C, and manufactured into predetermined shapes.
- An immersion nozzle according to Composition 1 was compared with the conventional nozzle of Composition A When using each nozzle four times with a 250 short ton (227 tonne) ladle for 240 minutes, the wear of the present nozzle was 0.021 mm/minute while the wear of the conventional nozzle A was 0.022 mm/minute. As for the pickup of carbon, the present nozzle showed no carbon pick up while the conventional nozzle showed a carbon pick up of 11 ppm by wt.
- An immersion nozzle according to Composition 2 was compared with the conventinal nozzle of composition B.
- the wear of the present nozzle was 0.015 mm/minute while the wear of the conventional nozzle be was 0.020 mm/minute.
- the pickup of carbon the present nozzle had a carbon pick up of only 1 ppm by wt while the conventional nozzle B had a carbon pickup of 10 ppm by wt.
- a long nozzle according to the Composition 3 was used between a ladle and a tundish six times with a 280 short ton (254 tonne) ladle for 300 minutes.
- the wear was 0.023 mm/minute and there was no carbon pickup.
- An immersion nozzle according to Composition 4 was compared with the conventional nozzle of compositon A.
- the wear of the nozzle of Composition 4 was 0.023 mm/minute and the wear of the conventional nozzle of Composition A was 0.022 mm.minute.
- the pickup of carbon the nozzle of Composition 4 showed no carbon pickup while the conventional nozzle of Composition A had a carbon pickup of 11 ppm by wt.
- An immersion nozzle according to Composition 5 was compared with the Comparative Example.
- the wear of the nozzle of the Comparative Example was so substantial that the nozzle broke off for the third time while the nozzle of Composition 5 was capable of casting five times for 250 minutes.
- the wear thereof was 0.020 mm/minute and the carbon pickup was 2 ppm by wt.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Ceramic Products (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Continuous Casting (AREA)
Abstract
Description
- The present invention relates to a nozzle for casting ultra low carbon steel. Amongst the various types of new steels which are of interest, an ultra low carbon steel has been proposed which contains less than 15 ppm carbon. As it is currently desirable to cast both killed-steel and oxygen-containing steel by the continuous casting process, a need has arisen for a casting nozzle suitable for casting ultra low carbon steels by the continuous casting process.
- As a consequence of the stringent quality requirements of modern steels, it has become necessary to use nozzles made of refractory materials which can ensure the continuous quality requirements described.
- We have found that if alumina-graphite nozzles, which are used for casting conventional, carbon-containing steels, are used for casting ultra-low carbon steels. carbon pickup becomes apparent either as the nozzle is worn away by the molten steel or through decarburization of the nozzle itself. Thus, we have found that conventional alumina-graphite nozzles are not suitable for use with ultra low carbon steels. Fused silica nozzles do not contain carbon. However, these nozzles are susceptible to wear, especially by high manganese steel.
- It is one object of the present invention to obviate or mitigate the problems of carbon pickup and excessive wear and provide a nozzle suitable for the continuous casting of ultra low carbon steels.
- In accordance with the present invention, there is provided a casting nozzle formed of a material comprising 70 to 98 weight % of a refractory material other than carbon or graphite, and 2 to 30 weight % of boron nitride.
- Preferably, the refractory material is selected from sintered or electrically fused magnesium, non-stabilized or semi-stabilized zirconia, alpha-alumina, beta-alumina, mullite, sillimanite, clay materials, fused silica, Si3N4, B4C and SiC.
- It is also preferable to add Si, Al or the like to the above composition to promote sintering and prevent oxidation of the nozzle material.
- Conveniently, an inorganic bonding agent is mixed with the composition, e.g in an amount of from 5 to 20 weight % of the composition. For example, there may be used as an inorganic bonding agent, clay (e.g. bentonite), waterglass, aluminium phosphate etc.
- Typically the nozzle of the present invention is made by moulding the present composition followed by sintering in a reducing atmosphere.
- If more than 30% boron nitride is used, then the nozzle is easily oxidized to B203 and wear of the nozzle is increased. If less than 2% boron nitride is used, the desirable characteristics of boron nitride, i.e. chemical inertness and high thermal conductivity are not shown and thermal shock spalling is increased.
- The present invention will be illustrated by the following examples (all percentages are by weight in the composition excluding the-inorganic bonding agent unless otherwise specified).
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- The respective compositions and bonding agents mentioned above are added with an appropriate amount of water and kneaded in a kneader for 40 minutes. The mixtures are dried in a drying furnace at 80°C for 12 hours so that the residual water content goes down to 1% to 3%, and thereafter crushed by a crusher to particles smaller than lmm.
- Rubber molds are filled with the thus prepared materials and molded under a molding pressure of 1,000 kg/cm2 in order to form immersion nozzles of predetermined shapes. The molding products are then sintered in a tunnel furnace whose ceiling temperature is 1250°C, and manufactured into predetermined shapes.
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- An immersion nozzle according to Composition 1 was compared with the conventional nozzle of Composition A When using each nozzle four times with a 250 short ton (227 tonne) ladle for 240 minutes, the wear of the present nozzle was 0.021 mm/minute while the wear of the conventional nozzle A was 0.022 mm/minute. As for the pickup of carbon, the present nozzle showed no carbon pick up while the conventional nozzle showed a carbon pick up of 11 ppm by wt.
- An immersion nozzle according to Composition 2 was compared with the conventinal nozzle of composition B. When using each nozzle five times with a 300 short ton (272 tonne) ladle for 250 minutes, the wear of the present nozzle was 0.015 mm/minute while the wear of the conventional nozzle be was 0.020 mm/minute. As for the pickup of carbon, the present nozzle had a carbon pick up of only 1 ppm by wt while the conventional nozzle B had a carbon pickup of 10 ppm by wt.
- A long nozzle according to the Composition 3 was used between a ladle and a tundish six times with a 280 short ton (254 tonne) ladle for 300 minutes. The wear was 0.023 mm/minute and there was no carbon pickup.
- An immersion nozzle according to Composition 4 was compared with the conventional nozzle of compositon A. When using each nozzle four times with a 250 short ton (227 tonne) ladle for 240 minutes, the wear of the nozzle of Composition 4 was 0.023 mm/minute and the wear of the conventional nozzle of Composition A was 0.022 mm.minute. As for the pickup of carbon, the nozzle of Composition 4 showed no carbon pickup while the conventional nozzle of Composition A had a carbon pickup of 11 ppm by wt.
- An immersion nozzle according to Composition 5 was compared with the Comparative Example. When using each nozzle five times with a 300 short ton (272 tonne) ladle, the wear of the nozzle of the Comparative Example was so substantial that the nozzle broke off for the third time while the nozzle of Composition 5 was capable of casting five times for 250 minutes. The wear thereof was 0.020 mm/minute and the carbon pickup was 2 ppm by wt.
Claims (6)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58089880A JPS59232959A (en) | 1983-05-19 | 1983-05-19 | Casting nozzle for super low carbon steel |
JP89880/83 | 1983-05-19 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0126560A2 true EP0126560A2 (en) | 1984-11-28 |
EP0126560A3 EP0126560A3 (en) | 1986-03-05 |
Family
ID=13983078
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84302838A Withdrawn EP0126560A3 (en) | 1983-05-19 | 1984-04-27 | Casting nozzle and method of casting using same |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0126560A3 (en) |
JP (1) | JPS59232959A (en) |
KR (1) | KR840009231A (en) |
AU (1) | AU2787584A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0256217A2 (en) * | 1986-08-12 | 1988-02-24 | Didier-Werke Ag | Submerged casting pipe and its manufacturing process |
EP0588218A1 (en) * | 1992-09-18 | 1994-03-23 | Akechi Ceramics Co. Ltd. | Molten steel pouring nozzle |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3915900A (en) * | 1972-08-18 | 1975-10-28 | Kempten Elektroschmelz Gmbh | Evaporator made from sintered refractory material |
US4007049A (en) * | 1968-08-06 | 1977-02-08 | The United States Of America As Represented By The Secretary Of The Air Force | Thermal shock resistant ceramic composite |
SU833868A1 (en) * | 1979-09-26 | 1981-05-30 | Ордена Трудового Красного Знамениинститут Проблем Материаловедения Ah Усср | Charge for producing refragtory material |
SU920049A1 (en) * | 1980-06-16 | 1982-04-15 | Ордена Трудового Красного Знамени Институт Проблем Материаловедения Ан Усср | Charge for making refractory material |
SU979301A1 (en) * | 1981-07-06 | 1982-12-07 | Ордена Трудового Красного Знамени Институт Проблем Материаловедения Ан Усср | Batch for making refractory material |
-
1983
- 1983-05-19 JP JP58089880A patent/JPS59232959A/en active Pending
-
1984
- 1984-03-28 KR KR1019840001617A patent/KR840009231A/en not_active IP Right Cessation
- 1984-04-27 EP EP84302838A patent/EP0126560A3/en not_active Withdrawn
- 1984-05-10 AU AU27875/84A patent/AU2787584A/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4007049A (en) * | 1968-08-06 | 1977-02-08 | The United States Of America As Represented By The Secretary Of The Air Force | Thermal shock resistant ceramic composite |
US3915900A (en) * | 1972-08-18 | 1975-10-28 | Kempten Elektroschmelz Gmbh | Evaporator made from sintered refractory material |
SU833868A1 (en) * | 1979-09-26 | 1981-05-30 | Ордена Трудового Красного Знамениинститут Проблем Материаловедения Ah Усср | Charge for producing refragtory material |
SU920049A1 (en) * | 1980-06-16 | 1982-04-15 | Ордена Трудового Красного Знамени Институт Проблем Материаловедения Ан Усср | Charge for making refractory material |
SU979301A1 (en) * | 1981-07-06 | 1982-12-07 | Ордена Трудового Красного Знамени Институт Проблем Материаловедения Ан Усср | Batch for making refractory material |
Non-Patent Citations (3)
Title |
---|
SOVIET INVENTIONS ILLUSTRATED, Section Chemical, Week E 13, 12th May 1982, abstract no. 25707 L/02, Derwent Publications Ltd., London, GB; & SU-A-833 868 (AS UKR MAT) 30-05-1981 * |
SOVIET INVENTIONS ILLUSTRATED, Section Chemical, Week K 07, 30th March 1983, abstract no. 17092 L/02, Derwent Publications Ltd., London, GB; & SU-A-920 049 (AS UKR MAT) 15-04-1982 * |
SOVIET INVENTIONS ILLUSTRATED, Section Chemical, Week K 40, 16th November 1983, abstract no. 83-781 647 L/02, Derwent Publications Ltd., London, GB; & SU-A-979 301 (AS UKR MAT) 07-12-1982 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0256217A2 (en) * | 1986-08-12 | 1988-02-24 | Didier-Werke Ag | Submerged casting pipe and its manufacturing process |
EP0256217A3 (en) * | 1986-08-12 | 1988-11-30 | Didier-Werke Ag | Submerged casting pipe and its manufacturing process |
EP0588218A1 (en) * | 1992-09-18 | 1994-03-23 | Akechi Ceramics Co. Ltd. | Molten steel pouring nozzle |
US5348203A (en) * | 1992-09-18 | 1994-09-20 | Akechi Ceramics Co., Ltd. | Molten steel pouring nozzle |
Also Published As
Publication number | Publication date |
---|---|
JPS59232959A (en) | 1984-12-27 |
AU2787584A (en) | 1984-11-22 |
EP0126560A3 (en) | 1986-03-05 |
KR840009231A (en) | 1984-12-26 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
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AK | Designated contracting states |
Designated state(s): DE FR GB |
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PUAL | Search report despatched |
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17P | Request for examination filed |
Effective date: 19860828 |
|
17Q | First examination report despatched |
Effective date: 19861216 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN |
|
18W | Application withdrawn |
Withdrawal date: 19870224 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: KONDO, MASANAO Inventor name: SUZUKI, HIRONOBU |