CA1168019A - Immersion nozzle for continuous casting of molten steel - Google Patents
Immersion nozzle for continuous casting of molten steelInfo
- Publication number
- CA1168019A CA1168019A CA000382324A CA382324A CA1168019A CA 1168019 A CA1168019 A CA 1168019A CA 000382324 A CA000382324 A CA 000382324A CA 382324 A CA382324 A CA 382324A CA 1168019 A CA1168019 A CA 1168019A
- Authority
- CA
- Canada
- Prior art keywords
- molten steel
- nozzle body
- refractory
- molten
- immersion nozzle
- 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.)
- Expired
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/6303—Inorganic additives
-
- 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
- B22D41/505—Rings, inserts or other means preventing external nozzle erosion by the slag
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
- C04B35/482—Refractories from grain sized mixtures
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- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/66—Monolithic refractories or refractory mortars, including those whether or not containing clay
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00612—Uses not provided for elsewhere in C04B2111/00 as one or more layers of a layered structure
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/0087—Uses not provided for elsewhere in C04B2111/00 for metallurgical applications
- C04B2111/00887—Ferrous metallurgy
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3244—Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3418—Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/38—Non-oxide ceramic constituents or additives
- C04B2235/3817—Carbides
- C04B2235/3826—Silicon carbides
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
- C04B2235/422—Carbon
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B2235/9669—Resistance against chemicals, e.g. against molten glass or molten salts
- C04B2235/9676—Resistance against chemicals, e.g. against molten glass or molten salts against molten metals such as steel or aluminium
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- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Composite Materials (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
- Continuous Casting (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An immersion nozzle for continuous casting of molten steel, which comprises: a nozzle body comprising an alumina-graphite refractory and a refractory layer excellent in erosion resistance against a molten mold powder, said refractory layer being arranged so as to be integral with said nozzle body and flush with the outer surface of said nozzle body at the outside portion of said nozzle body which is in contact, when the lower portion of said immersion nozzle is immersed into molten steel in a mold, with a molten meld powder layer on the meniscus of said molten steel; said immersion nozzle being characterized in that: said refractory layer arranged at said outside portion of said nozzle body consists essential-ly of, in weight percentage:
Carbon (C) from 10.5 to 26.5 %, Zirconia (ZrO2) from 70.0 to 86.0 %, At least one constituent selected from the group consisting of silicon (Si) and ferrosilicon (Fe-Si) from 0.5 to 15.0 %, and, Incidental impurities Up to 3 %.
An immersion nozzle for continuous casting of molten steel, which comprises: a nozzle body comprising an alumina-graphite refractory and a refractory layer excellent in erosion resistance against a molten mold powder, said refractory layer being arranged so as to be integral with said nozzle body and flush with the outer surface of said nozzle body at the outside portion of said nozzle body which is in contact, when the lower portion of said immersion nozzle is immersed into molten steel in a mold, with a molten meld powder layer on the meniscus of said molten steel; said immersion nozzle being characterized in that: said refractory layer arranged at said outside portion of said nozzle body consists essential-ly of, in weight percentage:
Carbon (C) from 10.5 to 26.5 %, Zirconia (ZrO2) from 70.0 to 86.0 %, At least one constituent selected from the group consisting of silicon (Si) and ferrosilicon (Fe-Si) from 0.5 to 15.0 %, and, Incidental impurities Up to 3 %.
Description
~L ~L 6 ~
REFERENCE TO PATENTS, APPLICATIONS AND PUBLICATIONS
PERTINENT TO T~E INVENTION
_ . .
So far as we know, prior documents pertinent to the present invention are as follows:
(1) ~apanese Pa~ent Publication No. 28,568/74 dated July 27, 1974; and,
REFERENCE TO PATENTS, APPLICATIONS AND PUBLICATIONS
PERTINENT TO T~E INVENTION
_ . .
So far as we know, prior documents pertinent to the present invention are as follows:
(1) ~apanese Pa~ent Publication No. 28,568/74 dated July 27, 1974; and,
(2) Japanese Patent Provisional Publication No. 46,-522/73 . dated July 3, 1973.
.
The prior ar~s disclosed in the above-mentioned prior documents will be commented on in the "BACKGROUND
OF THE INVENTION" presented hereafter.
FIELD OF THE INVENTION
The present invention relates to an immersion nozzle, which can serve for a long period of time, attached as a protrusion.substantially vertically to the bottom of a tundish for teeming molten steel fed to said tundish from a ladle into a mold in continuous casting of molten steel.
.
- 2 - ~ .
- .
BACKGROUND OF THE INVENTION
- A mald powder and an immersion nozzle are popularly used in continuously casting molten steel.
For example, a mold powder comprising 35.46 wt.
SiO~, 6.08 wt.% A12O3, 36.87 wt.% CaO, 8.05 wt.% Na2O, 5.33 wt.% ignition loss and impurities is added onto the meniscus of molten steel in a mold. The mold powder is melted into a vitreous state by heat from the molten steel to cover the molten steel meniscus, and at the same time, penetrates into gaps between sides of solidified steel and the mold inner walls to cover the surface of cast strand. The molten steel and the cast strand are thus isolated from air and protected from oxidationO Further-more, the molten mold powder layer absorbs non-metallic inclusions floating up on the molten steel meniscus.
.~
On the other hand, an immersion nozzle is attached as a protrusion substantially vertically to the bottom , of a tundish, and the lower portion thereof is immersed into the molten steel in the mold across the above-mentioned;
molten mold powder layer. The molten steel in the tundish flows down through the immersion nozzle and is teemed into the mold without being exposed to aix except during the initial stage of teeming.
' , - :,, :
.
' By using an immersion nozzle toyether with a mold p~wder! therefore, it is possible to ef~ectively prevent such inconveniences as oxidation of molten steel in the mold and the cast strand extracted from the mold, occurrence of turbu]ence in the molten steel, entanglement of air, mold powder and slag, and molten steel splash, thereby giving a sound cast strand excellent in surface quality as well as in inner quality.
Amorphous silica, zircon-graphite and alumina-graphite reE~actories are known as materials for the above-mentioned immersion nozzlej and an immersion nozzle is manufactured by forming any of these refractories into an appropriate shape and firing the formed body. Molten steel in a tundish is teemed into a mold through a collar portion, a bore, and an exit port of the immersion nozzle. The immersion nozzle, through the bore of which high-temperature molten steel flows down, is exposed to radical temperature changes and thermal shocks particularly in the initial stage of teeming, and in addition, the bore is eroded by molten steel. Furthermore, the portion of the outer sur~ace oE the nozzle body in contact with the molten mold powder layer is most seriously eroded by ~ pc/~
.
R~82~9 molten steel and molten mold powder. Along with the recent trend toward larger continuous casters, molten steel of more than five batches of ladle is often continuously teemed for casting.
An immersion nozzle is therefore required to have various properties to meet the aforementioned severe service conditions. Among these properties, those which have the most important effect on the service life and should there-fore be satisfied include spalling resistance in the initial staga of molten steel teeming, erosion resistance against molten steel and erosion resistance against molten mold powder. A nozzle which does not satisfy these three pro-perties at the same time cannot withstand continuous teeming of molten steel of more than five batches of ladle into a mold.
However, all the above-mentioned amorphous silica, zirconia-graphite and alumina-graphite refractories have respective merits and demerits, and it is very difficult to manufacture an immersion nozzle capable of withstanding the above-mentioned severe service conditions from single kind of refractory selected from those mentioned above.
More specifically, the amorphous silica refractory has a very small thermal expansion and a relatively satisfactory erosion resistance against molten mold powder as from 2 to 3 mm per c~cle of continuous casting of molten steel of a batch of ladle. On the contrary, however, the amorphous silica refractory is susceptible to spalling because of transformation of amorphous silica during service for a long period of time, and has a relatively low eroslon r~sistance against molten steel, particularly high-Mh molten steel~ The zircon-graphite refractory has a relatively satisfactory erosion resistance against molten steel, while erosion resistance thereof against molten mold powder is problematic. The alumina-graphite refractory has a good erosion resistance against molten steel. The zircon-graphite and alumina-graphite refract-ries, both containing graphite, have a high thermal conductivity and hence are capable of well withstanding radical temperature change and thermal shock. In contrast, however, the structure becomes porous as a result of oxidation and/or dissolution into molten steel of graphite, and erosion is caused by molten steel and molten mold powder penetrating into portions thus becoming porous, this forming a drawback com~lon to these refractories.
With a view to solving the aforementioned problems and thus improving erosion resistance against molten steel and erosion resistance against molten mold powder as required for an immersion nozzle, the following immersion nozzles are proposed: `
.L~
~(1) An immersion nozzle for continuous castiny disclosed in Japanese Patent Publication No. 28,568/74 dated July 27, 1974, wherein:
a highly erosion-resistant refractory layer made -of a rnaterial such as a zirconia .refractory is arranged on at least one of the inner surface of a bore and an exit port of a nozzle body mainly comprising amorphous silica, and the outside portio~ cf the nozzle body in contact with a molten mold powder layer, so as to be flush with the inner and outer surfaces of the nozzle body; and zirconia, silica-zirconia, zirconia-mullite, mullite and chromium oxide refractories are suitable as the highly erosion-resistant refractory (hereinafter referred to as the "prior art (1)'`).
In the prior art (1), the nozzle body comprises mainly amorphous silica. Amorphous silica has a very small thermal expansion and a relati.vely satisEactory erosion resistance against molten mold powder, as mentioned above, while havin~ a relatively low erosion resistance against molten steel.
~lso .in the prior art (1), zirconia (ZrO~) which is the main material of the refractory layerls) arranged in the bore of the nozzle body and/or on the outside portion of the nozzle body has an e~cellent erosion resistance against molten mold powder. However, in ~iring, there occurs a considerable difference in thermal expansion between the arranged refractory layer(s) having a high thermal expansion and the nozzle body comprising amorphous silica having a very small thermal expansion, and as a result, spalling may be caused in both the nozzle body and the aforementioned . ''.',.. pc/ ~
~ portion(s). It is thus difficult to obtain an ir~ersion nozzle free from deEects.
It is therefore difficult for the immersion nozzle of the prior art (1~ to withstand severe service conditions includiny continuous cas-ting of molten steel or more than five ladle batches.
(2) An immersion nozzle for continuous casting disclosed in Japanese Patent Provisional Publication No. 46,522/73 of July 3, 1973, wherein:
A refractory layer excellent in erosion resistance against molten mold powder is arranged on the entire surface of the nozzle body comprising a refractory excellent in erosion resistance agains-t molten steel or on the outside portion thereof in contact with a molten mold powder layer, so as to be flush with the outer surEace of said nozzle A
pc/~ 8 -body, or, to form a protrusion from the outer surface of said nozzle body; alumina-graphite refractory is suitable as said refractory excellent in erosion resistance against molten steel, and amorphous silica refractory is suitable as said refractory excellent in erosion xesistance against molten mold powder (hereinafter referred to as the "prior art (2)").
In ~he prior art ~2~, the nozzle body comprises mainly alumina-graphite as in the present invention described later. As mentioned above, alumina-graphite is excellent in erosion resistance against molten steel.
Also, in the prior art (2), the main material for the refractory layer arranged on the outside portion of the nozzle body is amorphous silica. As described above, amorphous silica has a relatively satis~actory erosion resistance against molten mold powder, while having a low erosion resistance against molten steel. In addition, amorphous silica is susceptible to spalling because of transformation of amorphous silica during service for a long period of time.
Therefore, the immersion nozzle of the prior art (2) obtained by arranging an amorphous silica refractory layer having a low erosion resistance against molten steel - on the outside portion of the nozzle body in contact with molten mold powder layer is problematic in eroslon resis-tance against molten steel and it is difficult for such an immersion nozzle to continuously cast molten steel of more than five batches of ladle.
S SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide an immersion nozzle which, when continuously - casting molten steel, can withstand a long service, especially continuous casting of molten steel of more than five batches of ladle.
A principal object of the present invention is to provide an immersion nozzle, of which the outside portion in contact, when continuously casting molten steel, with a molten mold powder layer on the meniscus of molten steel in a mold is excellent not only in erosion resistance against molten steel but also especially in erosion resis-tance against molten mold powder.
In accordance with one of the features of the present invention, there is provided an immersion nozzle ~or continuous casting of molten steel, which comprises:
a nozzle body comprising an alumina-graphite refractory and a refractory layer excellent in erosion r ' ~ .
~esistance against a mol~en mold powder, said refractory layer being arranged so as to be integral with said nozzle body and flush with the outer surface of said nozzIe body at the outside portion of said nozzle body :~ 5 which is in contact, when the lower portion of said immersion nozzle is immersed into molten steel in a mold, with a molten mold powder layer on the meniscus of said lten steel;
said immersion nozzle being characterized in that:
said refractory layer arranged at said outside . portion of said nozzle body consists essentially of, in weight percentage:
: . Carbon (C) from 10.5 to 26.5 ~, Zirconia (ZrO2) from 70.0 to 86.0 %, lS At least one constituent selected from the group consisting o silicon (Si) and ferrosilicon (Fe-Si) `~ rom 0.5 to 15.0 %, and, Incidental impurities up to 3 %.
BRIEF DESCRIPTION OF THE DRAWINGS
... .
Fig. 1 is a schematic sectional view illustrating a conventional immersion nozzle for continuous casting of molten steel;
Fig. 2 is a schematic sectional view illustrating another conventional immersion nozzle for continuous casting of molten steel; and, Fig. 3 is a schematic sec~ional view illustrating the immersion nozzle for continuous casting of molten steel of the present invention.
~ETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
. _ . . . _ . _ .. . .. .
From the aforementioned point of view, we have carried out extensive studies to obtain an immersion nozzle capable of withstanding a long service, especially continu-ous casting of molten steel of more than five batches of ladle. As a result, we found that it is possible to obtain an immersion nozzle capable of withstanding continuous cast-ing of molten steel of more than five batches of ladle byforming a nozzle body with an alumina-graphite, and arranging, at the outside portion of said nozzle body which is in contact, when immersed into molten steel, with a molten mold powder layer on the meniscus of said molten steel, a refractory layer consisting essentially of:
Carbon (C) from 10.5 to 26.5 %, Zirconia (ZrO2) from 70.0 to 86.0 %, . . .
~~8~319 . .
At least one constituent selected from the group .: consisting of silicon (Si) and ferrosilicon (Fe-Si) from 0.5 to 15.0 ~, and, ; 5 Indcidental impurities up to 3 %.
so as to be integral with said nozzle body and flush with the outer surface of said nozzle body.
Fig. 3 is a schematic sectional view illustrating , i an embodiment of the immersion nozzle for continuous casting of molten steel of the present invention. In Fig. 3, lO
is a nozzle body, 11 is a refractory layer arranged at ~` the outside portion of the nozzle body 10 in contact with a molten mold powder layer 14 on the meniscus of molten steel 13 in a mold 12, 15 is a collar portion of the nozzle body lO, 16 is a bore of the nozzle body 10, and 17 is an exit port of the bore 16. Molten steel in a tundish (not shown) is teemed into the mold 12 through the collar portion 15, the bore 16 and the exit port 17 while the flow rate of molten steel is ad~usted by a stopper (not shown).
The nozzle body 10 may be made of an alumina-graphlte refractory having a known chemical composition, or more preferably, an alumina-graphlte refractory having, .
~' , for example, any of the following chemical compositions:
: from 48.0 to 51.0 wt.% alumina, from 19.0 to 21.0 wto%
carbon and from 28.0 to 31.0 wt.~ balancei or from 44.0 to 48.0 wt.% alumina, from 25.0 to 28.0 wt.% carbon, and from 26.0 to 29.0 wt.% balance. An alumina-graphite refractory is excellent in erosion resistance against molten steel and has a high thermal conductivity because of carbon contained. Therefore, the bore 16, the exit port 17 and the portlon immersed into molten steel of the nozzle body 10 made of an alumina-graphite refractory are less susceptible to erosion by molten steel, exposed to reduced temperature change and thermal shock in the initial stage of teeming of molten steel and protected from occur-rence of spalling.
In the present invention, the reasons of limiting the chemical composition of the refractory layer 11 arranged at the outside portion of the nozzle body 10 in contact with the molten powder layer 14 as mentioned above are as follows:
.
~1) Carbon (C):
Car~on (C) has the effect of not only raising the thermal conductivity but also reducing the thermal ex- :.
pansivity of a refractory. Furthermore, carbon has the ~, ~6~
effect of improving spallin~ resistance and wetting resis-tance against molten steel of a refractory. However, with a carbon content of under 10.5 wt.%, a desired effect cannot be obtained as mentioned above. The carbon content should therefore be at least 10.5 wt.%. On the other hand, with a carbon content of over 26.5 wt.%, carbon is partially oxidized and dissolved into molten steel, and as a result, the refractory becomes porous. Molten steel and molten mold powder penetrating into portions thus becoming porous erode zirconia as described later. The carbon content should therefore be up to 26.S wt.~. Carbon may be either graphite or amorphous carbon.
(2) Zirconia (ZrO2) Zirconia (ZrO2) is added to prevent erosion by a molten mold powder because of the very hi~h erosion resistance thereof against molten mold powder. However, with a zirconia content of under 70.0 wt.%, a desired erosion resistance against m~lten mold powder cannot be obtained. The zirconia content should therefore be at least 70.0 wt.~ On the o~her hand, because of the high thermal expansivity of zirconia, a zirconia content of over 86.0~ tends to cause spalling in the initial stage of molten steel teeming. The zirconia content should therefore be up to 86.0 wt.%. ~ny of stabilized , 8~3~9 zirconia and nonstabilized zirconia may be used.
.
The prior ar~s disclosed in the above-mentioned prior documents will be commented on in the "BACKGROUND
OF THE INVENTION" presented hereafter.
FIELD OF THE INVENTION
The present invention relates to an immersion nozzle, which can serve for a long period of time, attached as a protrusion.substantially vertically to the bottom of a tundish for teeming molten steel fed to said tundish from a ladle into a mold in continuous casting of molten steel.
.
- 2 - ~ .
- .
BACKGROUND OF THE INVENTION
- A mald powder and an immersion nozzle are popularly used in continuously casting molten steel.
For example, a mold powder comprising 35.46 wt.
SiO~, 6.08 wt.% A12O3, 36.87 wt.% CaO, 8.05 wt.% Na2O, 5.33 wt.% ignition loss and impurities is added onto the meniscus of molten steel in a mold. The mold powder is melted into a vitreous state by heat from the molten steel to cover the molten steel meniscus, and at the same time, penetrates into gaps between sides of solidified steel and the mold inner walls to cover the surface of cast strand. The molten steel and the cast strand are thus isolated from air and protected from oxidationO Further-more, the molten mold powder layer absorbs non-metallic inclusions floating up on the molten steel meniscus.
.~
On the other hand, an immersion nozzle is attached as a protrusion substantially vertically to the bottom , of a tundish, and the lower portion thereof is immersed into the molten steel in the mold across the above-mentioned;
molten mold powder layer. The molten steel in the tundish flows down through the immersion nozzle and is teemed into the mold without being exposed to aix except during the initial stage of teeming.
' , - :,, :
.
' By using an immersion nozzle toyether with a mold p~wder! therefore, it is possible to ef~ectively prevent such inconveniences as oxidation of molten steel in the mold and the cast strand extracted from the mold, occurrence of turbu]ence in the molten steel, entanglement of air, mold powder and slag, and molten steel splash, thereby giving a sound cast strand excellent in surface quality as well as in inner quality.
Amorphous silica, zircon-graphite and alumina-graphite reE~actories are known as materials for the above-mentioned immersion nozzlej and an immersion nozzle is manufactured by forming any of these refractories into an appropriate shape and firing the formed body. Molten steel in a tundish is teemed into a mold through a collar portion, a bore, and an exit port of the immersion nozzle. The immersion nozzle, through the bore of which high-temperature molten steel flows down, is exposed to radical temperature changes and thermal shocks particularly in the initial stage of teeming, and in addition, the bore is eroded by molten steel. Furthermore, the portion of the outer sur~ace oE the nozzle body in contact with the molten mold powder layer is most seriously eroded by ~ pc/~
.
R~82~9 molten steel and molten mold powder. Along with the recent trend toward larger continuous casters, molten steel of more than five batches of ladle is often continuously teemed for casting.
An immersion nozzle is therefore required to have various properties to meet the aforementioned severe service conditions. Among these properties, those which have the most important effect on the service life and should there-fore be satisfied include spalling resistance in the initial staga of molten steel teeming, erosion resistance against molten steel and erosion resistance against molten mold powder. A nozzle which does not satisfy these three pro-perties at the same time cannot withstand continuous teeming of molten steel of more than five batches of ladle into a mold.
However, all the above-mentioned amorphous silica, zirconia-graphite and alumina-graphite refractories have respective merits and demerits, and it is very difficult to manufacture an immersion nozzle capable of withstanding the above-mentioned severe service conditions from single kind of refractory selected from those mentioned above.
More specifically, the amorphous silica refractory has a very small thermal expansion and a relatively satisfactory erosion resistance against molten mold powder as from 2 to 3 mm per c~cle of continuous casting of molten steel of a batch of ladle. On the contrary, however, the amorphous silica refractory is susceptible to spalling because of transformation of amorphous silica during service for a long period of time, and has a relatively low eroslon r~sistance against molten steel, particularly high-Mh molten steel~ The zircon-graphite refractory has a relatively satisfactory erosion resistance against molten steel, while erosion resistance thereof against molten mold powder is problematic. The alumina-graphite refractory has a good erosion resistance against molten steel. The zircon-graphite and alumina-graphite refract-ries, both containing graphite, have a high thermal conductivity and hence are capable of well withstanding radical temperature change and thermal shock. In contrast, however, the structure becomes porous as a result of oxidation and/or dissolution into molten steel of graphite, and erosion is caused by molten steel and molten mold powder penetrating into portions thus becoming porous, this forming a drawback com~lon to these refractories.
With a view to solving the aforementioned problems and thus improving erosion resistance against molten steel and erosion resistance against molten mold powder as required for an immersion nozzle, the following immersion nozzles are proposed: `
.L~
~(1) An immersion nozzle for continuous castiny disclosed in Japanese Patent Publication No. 28,568/74 dated July 27, 1974, wherein:
a highly erosion-resistant refractory layer made -of a rnaterial such as a zirconia .refractory is arranged on at least one of the inner surface of a bore and an exit port of a nozzle body mainly comprising amorphous silica, and the outside portio~ cf the nozzle body in contact with a molten mold powder layer, so as to be flush with the inner and outer surfaces of the nozzle body; and zirconia, silica-zirconia, zirconia-mullite, mullite and chromium oxide refractories are suitable as the highly erosion-resistant refractory (hereinafter referred to as the "prior art (1)'`).
In the prior art (1), the nozzle body comprises mainly amorphous silica. Amorphous silica has a very small thermal expansion and a relati.vely satisEactory erosion resistance against molten mold powder, as mentioned above, while havin~ a relatively low erosion resistance against molten steel.
~lso .in the prior art (1), zirconia (ZrO~) which is the main material of the refractory layerls) arranged in the bore of the nozzle body and/or on the outside portion of the nozzle body has an e~cellent erosion resistance against molten mold powder. However, in ~iring, there occurs a considerable difference in thermal expansion between the arranged refractory layer(s) having a high thermal expansion and the nozzle body comprising amorphous silica having a very small thermal expansion, and as a result, spalling may be caused in both the nozzle body and the aforementioned . ''.',.. pc/ ~
~ portion(s). It is thus difficult to obtain an ir~ersion nozzle free from deEects.
It is therefore difficult for the immersion nozzle of the prior art (1~ to withstand severe service conditions includiny continuous cas-ting of molten steel or more than five ladle batches.
(2) An immersion nozzle for continuous casting disclosed in Japanese Patent Provisional Publication No. 46,522/73 of July 3, 1973, wherein:
A refractory layer excellent in erosion resistance against molten mold powder is arranged on the entire surface of the nozzle body comprising a refractory excellent in erosion resistance agains-t molten steel or on the outside portion thereof in contact with a molten mold powder layer, so as to be flush with the outer surEace of said nozzle A
pc/~ 8 -body, or, to form a protrusion from the outer surface of said nozzle body; alumina-graphite refractory is suitable as said refractory excellent in erosion resistance against molten steel, and amorphous silica refractory is suitable as said refractory excellent in erosion xesistance against molten mold powder (hereinafter referred to as the "prior art (2)").
In ~he prior art ~2~, the nozzle body comprises mainly alumina-graphite as in the present invention described later. As mentioned above, alumina-graphite is excellent in erosion resistance against molten steel.
Also, in the prior art (2), the main material for the refractory layer arranged on the outside portion of the nozzle body is amorphous silica. As described above, amorphous silica has a relatively satis~actory erosion resistance against molten mold powder, while having a low erosion resistance against molten steel. In addition, amorphous silica is susceptible to spalling because of transformation of amorphous silica during service for a long period of time.
Therefore, the immersion nozzle of the prior art (2) obtained by arranging an amorphous silica refractory layer having a low erosion resistance against molten steel - on the outside portion of the nozzle body in contact with molten mold powder layer is problematic in eroslon resis-tance against molten steel and it is difficult for such an immersion nozzle to continuously cast molten steel of more than five batches of ladle.
S SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide an immersion nozzle which, when continuously - casting molten steel, can withstand a long service, especially continuous casting of molten steel of more than five batches of ladle.
A principal object of the present invention is to provide an immersion nozzle, of which the outside portion in contact, when continuously casting molten steel, with a molten mold powder layer on the meniscus of molten steel in a mold is excellent not only in erosion resistance against molten steel but also especially in erosion resis-tance against molten mold powder.
In accordance with one of the features of the present invention, there is provided an immersion nozzle ~or continuous casting of molten steel, which comprises:
a nozzle body comprising an alumina-graphite refractory and a refractory layer excellent in erosion r ' ~ .
~esistance against a mol~en mold powder, said refractory layer being arranged so as to be integral with said nozzle body and flush with the outer surface of said nozzIe body at the outside portion of said nozzle body :~ 5 which is in contact, when the lower portion of said immersion nozzle is immersed into molten steel in a mold, with a molten mold powder layer on the meniscus of said lten steel;
said immersion nozzle being characterized in that:
said refractory layer arranged at said outside . portion of said nozzle body consists essentially of, in weight percentage:
: . Carbon (C) from 10.5 to 26.5 ~, Zirconia (ZrO2) from 70.0 to 86.0 %, lS At least one constituent selected from the group consisting o silicon (Si) and ferrosilicon (Fe-Si) `~ rom 0.5 to 15.0 %, and, Incidental impurities up to 3 %.
BRIEF DESCRIPTION OF THE DRAWINGS
... .
Fig. 1 is a schematic sectional view illustrating a conventional immersion nozzle for continuous casting of molten steel;
Fig. 2 is a schematic sectional view illustrating another conventional immersion nozzle for continuous casting of molten steel; and, Fig. 3 is a schematic sec~ional view illustrating the immersion nozzle for continuous casting of molten steel of the present invention.
~ETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
. _ . . . _ . _ .. . .. .
From the aforementioned point of view, we have carried out extensive studies to obtain an immersion nozzle capable of withstanding a long service, especially continu-ous casting of molten steel of more than five batches of ladle. As a result, we found that it is possible to obtain an immersion nozzle capable of withstanding continuous cast-ing of molten steel of more than five batches of ladle byforming a nozzle body with an alumina-graphite, and arranging, at the outside portion of said nozzle body which is in contact, when immersed into molten steel, with a molten mold powder layer on the meniscus of said molten steel, a refractory layer consisting essentially of:
Carbon (C) from 10.5 to 26.5 %, Zirconia (ZrO2) from 70.0 to 86.0 %, . . .
~~8~319 . .
At least one constituent selected from the group .: consisting of silicon (Si) and ferrosilicon (Fe-Si) from 0.5 to 15.0 ~, and, ; 5 Indcidental impurities up to 3 %.
so as to be integral with said nozzle body and flush with the outer surface of said nozzle body.
Fig. 3 is a schematic sectional view illustrating , i an embodiment of the immersion nozzle for continuous casting of molten steel of the present invention. In Fig. 3, lO
is a nozzle body, 11 is a refractory layer arranged at ~` the outside portion of the nozzle body 10 in contact with a molten mold powder layer 14 on the meniscus of molten steel 13 in a mold 12, 15 is a collar portion of the nozzle body lO, 16 is a bore of the nozzle body 10, and 17 is an exit port of the bore 16. Molten steel in a tundish (not shown) is teemed into the mold 12 through the collar portion 15, the bore 16 and the exit port 17 while the flow rate of molten steel is ad~usted by a stopper (not shown).
The nozzle body 10 may be made of an alumina-graphlte refractory having a known chemical composition, or more preferably, an alumina-graphlte refractory having, .
~' , for example, any of the following chemical compositions:
: from 48.0 to 51.0 wt.% alumina, from 19.0 to 21.0 wto%
carbon and from 28.0 to 31.0 wt.~ balancei or from 44.0 to 48.0 wt.% alumina, from 25.0 to 28.0 wt.% carbon, and from 26.0 to 29.0 wt.% balance. An alumina-graphite refractory is excellent in erosion resistance against molten steel and has a high thermal conductivity because of carbon contained. Therefore, the bore 16, the exit port 17 and the portlon immersed into molten steel of the nozzle body 10 made of an alumina-graphite refractory are less susceptible to erosion by molten steel, exposed to reduced temperature change and thermal shock in the initial stage of teeming of molten steel and protected from occur-rence of spalling.
In the present invention, the reasons of limiting the chemical composition of the refractory layer 11 arranged at the outside portion of the nozzle body 10 in contact with the molten powder layer 14 as mentioned above are as follows:
.
~1) Carbon (C):
Car~on (C) has the effect of not only raising the thermal conductivity but also reducing the thermal ex- :.
pansivity of a refractory. Furthermore, carbon has the ~, ~6~
effect of improving spallin~ resistance and wetting resis-tance against molten steel of a refractory. However, with a carbon content of under 10.5 wt.%, a desired effect cannot be obtained as mentioned above. The carbon content should therefore be at least 10.5 wt.%. On the other hand, with a carbon content of over 26.5 wt.%, carbon is partially oxidized and dissolved into molten steel, and as a result, the refractory becomes porous. Molten steel and molten mold powder penetrating into portions thus becoming porous erode zirconia as described later. The carbon content should therefore be up to 26.S wt.~. Carbon may be either graphite or amorphous carbon.
(2) Zirconia (ZrO2) Zirconia (ZrO2) is added to prevent erosion by a molten mold powder because of the very hi~h erosion resistance thereof against molten mold powder. However, with a zirconia content of under 70.0 wt.%, a desired erosion resistance against m~lten mold powder cannot be obtained. The zirconia content should therefore be at least 70.0 wt.~ On the o~her hand, because of the high thermal expansivity of zirconia, a zirconia content of over 86.0~ tends to cause spalling in the initial stage of molten steel teeming. The zirconia content should therefore be up to 86.0 wt.%. ~ny of stabilized , 8~3~9 zirconia and nonstabilized zirconia may be used.
(3) Silicon (Si) and ferrosilicon (Fe-Si):
As mentioned above, carbon tends to be oxidized and dissolved into molten steel. To compensate this inconvenience, therefore, silicon (Si) and/or ferrosilicon (Fe-Si) are added~ More specifically, before oxidation of carbon, silicon and/or ferrosilicon are oxidized or carbonized to produce silica or silicon carbide. As a -; result, it is possible to reduce the tendency of refractory becoming porous caused by the oxidation of carbon or dissolution of carbon into molten steel. However, with a content of silicon and/or ferrosilicon of under 0.5 wt.-%, a desired effect cannot be obtained as mentioned above.
Therefore, the content of silicon and/or ferrosilicon should be at least 0.5 wt.~. On the other hand, with a ; content of silicon and/or ferrosilicon of over 15.0 wt.%, the aforementioned zirconia content is relatively reduced, thus making it impossible to obtain a desired erosion resistance against molten mold powder. Therefore, the content of silicon and/or ferrosilicon should be up to 15.0 wt.%.
In case that the nozzle body has a thickness of from 20 to 25 mm, the thickness of from 10 to 15 mm suffices .~, - , ~, ': .
for the thickness of the refractory layer having the above-- mentioned chemical composition and arranged at the outside portion of the nozzle body which is in contact with molten mold powdex layer.
Now, the immersion nozzle of the present invention is described in more detail with reference to examples:
EXAMæLE
A conventional alumina-graphite refractory was used as the material for a nozzle body 10 shown in Fig. 3.
A refractory comprising:
Graphite : 15 wt.%
Nonstabilized zirconia : 75 wt.%, and Silicon : 10 wt.~, ' mixed with tar and pitch as binders was used as the material for the refractory layer 11 arranged at the outside portion of the nozzle body 10, which is in contact with the molten mold powder layer 14. These refractories were formed by a conventional rubber press method and fired, and as shown in Fig. 3, an immersion nozzle with a thickness of 30 mm (the refractory layer 11 having a thickness, of 15 mm) was preparedl in which a refractory layer 11 excellent in erosion resistance against molten mold powder was integrally . .
arranged at the outside portion of the nozzle body 10 and in contact with the molten mold powder layer 14.
Then, an aluminum-killed steel in an amount of six batches of 250-ton ladle was continuously teemed into two strands with the use of the immersion nozzle thus prepared. The refractory layer 11 of the immersion nozzle showed on its one side an erosion of only 10 mm at maximum.
For the purpose of the comparison, on the other hand, an aluminum-killed steel in an amount of three batches of 250-ton ladle was continuously teemed into two strands with the use of a conventional immersion nozzle (with a thickness of 30 mm) shown in Fig. 1 made from a single kind of alumina-graphite refractory. The outside portion o the conventional immersion nozzle, which is in contact with the molten mold powder layer, showed on its one side a serious erosion reaching 25 mm at maximum, and it was impossible to further continue continuous casting.
An immerslon nozzle was prepared under the same conditions as in Example 1, which had the same construction ~ .
,.
as the immersion nozzle in Example 1 except that a refractory comprising:
j~
f~ Graphite : ~ wt.%, Ferrosilicon : 5 wt.~, and MgO-stabili~ed zirconia ~ wt.~
mixed with phenol resin as the binder was used as the material for the refractory layer ll arranged at ~he portion of the nozzle body 10 in contact with the molten mold powder layer 14.
Then,an aluminum~silicon-killed steel in an amount of eight batches of 100-ton ladle was continuously teemed into one strand with the use of the immersion nozzle thus prepared. The refractory layer 11 of the immersion nozzle showed on its one side an erosion of 16 mm at maximum, permitting use at ease.
For the purpose of the comparison, on the other hand, an aluminum-silicon-killed steel in an amount of three batches of 100-ton ladle was continuously teemed into one strand with the use of a conventional immersion nozzle made from the same single kind of alumina graphite refractory as in Example 1. The conventional immersion nozzle was broken by melting.
According to the present invention, as described I .
' .~ .
above in detail, it is possible to obtain an immersion nozzle for continuous casting of molten steel, which can withstand casting of molten steel of more than five batches of ladle and has a service life of from two to S three times as long as that of a conventional immersion nozzle, ~hus providing industrially useful effects.
- ~ .
As mentioned above, carbon tends to be oxidized and dissolved into molten steel. To compensate this inconvenience, therefore, silicon (Si) and/or ferrosilicon (Fe-Si) are added~ More specifically, before oxidation of carbon, silicon and/or ferrosilicon are oxidized or carbonized to produce silica or silicon carbide. As a -; result, it is possible to reduce the tendency of refractory becoming porous caused by the oxidation of carbon or dissolution of carbon into molten steel. However, with a content of silicon and/or ferrosilicon of under 0.5 wt.-%, a desired effect cannot be obtained as mentioned above.
Therefore, the content of silicon and/or ferrosilicon should be at least 0.5 wt.~. On the other hand, with a ; content of silicon and/or ferrosilicon of over 15.0 wt.%, the aforementioned zirconia content is relatively reduced, thus making it impossible to obtain a desired erosion resistance against molten mold powder. Therefore, the content of silicon and/or ferrosilicon should be up to 15.0 wt.%.
In case that the nozzle body has a thickness of from 20 to 25 mm, the thickness of from 10 to 15 mm suffices .~, - , ~, ': .
for the thickness of the refractory layer having the above-- mentioned chemical composition and arranged at the outside portion of the nozzle body which is in contact with molten mold powdex layer.
Now, the immersion nozzle of the present invention is described in more detail with reference to examples:
EXAMæLE
A conventional alumina-graphite refractory was used as the material for a nozzle body 10 shown in Fig. 3.
A refractory comprising:
Graphite : 15 wt.%
Nonstabilized zirconia : 75 wt.%, and Silicon : 10 wt.~, ' mixed with tar and pitch as binders was used as the material for the refractory layer 11 arranged at the outside portion of the nozzle body 10, which is in contact with the molten mold powder layer 14. These refractories were formed by a conventional rubber press method and fired, and as shown in Fig. 3, an immersion nozzle with a thickness of 30 mm (the refractory layer 11 having a thickness, of 15 mm) was preparedl in which a refractory layer 11 excellent in erosion resistance against molten mold powder was integrally . .
arranged at the outside portion of the nozzle body 10 and in contact with the molten mold powder layer 14.
Then, an aluminum-killed steel in an amount of six batches of 250-ton ladle was continuously teemed into two strands with the use of the immersion nozzle thus prepared. The refractory layer 11 of the immersion nozzle showed on its one side an erosion of only 10 mm at maximum.
For the purpose of the comparison, on the other hand, an aluminum-killed steel in an amount of three batches of 250-ton ladle was continuously teemed into two strands with the use of a conventional immersion nozzle (with a thickness of 30 mm) shown in Fig. 1 made from a single kind of alumina-graphite refractory. The outside portion o the conventional immersion nozzle, which is in contact with the molten mold powder layer, showed on its one side a serious erosion reaching 25 mm at maximum, and it was impossible to further continue continuous casting.
An immerslon nozzle was prepared under the same conditions as in Example 1, which had the same construction ~ .
,.
as the immersion nozzle in Example 1 except that a refractory comprising:
j~
f~ Graphite : ~ wt.%, Ferrosilicon : 5 wt.~, and MgO-stabili~ed zirconia ~ wt.~
mixed with phenol resin as the binder was used as the material for the refractory layer ll arranged at ~he portion of the nozzle body 10 in contact with the molten mold powder layer 14.
Then,an aluminum~silicon-killed steel in an amount of eight batches of 100-ton ladle was continuously teemed into one strand with the use of the immersion nozzle thus prepared. The refractory layer 11 of the immersion nozzle showed on its one side an erosion of 16 mm at maximum, permitting use at ease.
For the purpose of the comparison, on the other hand, an aluminum-silicon-killed steel in an amount of three batches of 100-ton ladle was continuously teemed into one strand with the use of a conventional immersion nozzle made from the same single kind of alumina graphite refractory as in Example 1. The conventional immersion nozzle was broken by melting.
According to the present invention, as described I .
' .~ .
above in detail, it is possible to obtain an immersion nozzle for continuous casting of molten steel, which can withstand casting of molten steel of more than five batches of ladle and has a service life of from two to S three times as long as that of a conventional immersion nozzle, ~hus providing industrially useful effects.
- ~ .
Claims
1. An immersion nozzle for continuous casting of molten steel, which comprises:
a nozzle body comprising an alumina-graphite refractory and a refractory layer excellent in erosion resistance against a molten mold powder, said refractory layer being arranged so as to be integral with said nozzle body and flush with the outer surface of said nozzle body and positioned at the outside portion of said nozzle body which is in contact, when the lower portion of said immersion nozzle is immersed into molten steel in a mold, with a molten mold powder layer on the meniscus of said molten steel;
said immersion nozzle being characterized in that:
said refractory layer arranged at said outside portion of said nozzle body consists essentially of, in weight percentage:
Carbon (C) from 10.5 to 26.5 %, Zirconia (ZrO2) from 70.0 to 86.0 %, At least one constituent selected from the group consisting of silicon (Si) and ferrosilicon (Fe-Si) from 0.5 to 15.0 %, and, Incidental impurities up to 3 %.
a nozzle body comprising an alumina-graphite refractory and a refractory layer excellent in erosion resistance against a molten mold powder, said refractory layer being arranged so as to be integral with said nozzle body and flush with the outer surface of said nozzle body and positioned at the outside portion of said nozzle body which is in contact, when the lower portion of said immersion nozzle is immersed into molten steel in a mold, with a molten mold powder layer on the meniscus of said molten steel;
said immersion nozzle being characterized in that:
said refractory layer arranged at said outside portion of said nozzle body consists essentially of, in weight percentage:
Carbon (C) from 10.5 to 26.5 %, Zirconia (ZrO2) from 70.0 to 86.0 %, At least one constituent selected from the group consisting of silicon (Si) and ferrosilicon (Fe-Si) from 0.5 to 15.0 %, and, Incidental impurities up to 3 %.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP107656/80 | 1980-08-07 | ||
| JP10765680A JPS5732858A (en) | 1980-08-07 | 1980-08-07 | Immersion nozzle for continuous casting of molten steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1168019A true CA1168019A (en) | 1984-05-29 |
Family
ID=14464698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000382324A Expired CA1168019A (en) | 1980-08-07 | 1981-07-23 | Immersion nozzle for continuous casting of molten steel |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS5732858A (en) |
| KR (1) | KR830005940A (en) |
| AU (1) | AU544800B2 (en) |
| BE (1) | BE889870A (en) |
| BR (1) | BR8105045A (en) |
| CA (1) | CA1168019A (en) |
| DE (1) | DE3131068C2 (en) |
| FR (1) | FR2488165A1 (en) |
| GB (1) | GB2081702B (en) |
| IT (1) | IT1138906B (en) |
| ZA (1) | ZA815030B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4898226A (en) * | 1987-06-01 | 1990-02-06 | Nkk Corporation | Immersion nozzle for continuous casting of steel |
| JPH0767602B2 (en) * | 1987-06-01 | 1995-07-26 | 日本鋼管株式会社 | Continuous casting immersion nozzle |
| JPH01284468A (en) * | 1988-05-11 | 1989-11-15 | Sumitomo Metal Ind Ltd | Submerged nozzle for continuous casting |
| WO2000021702A1 (en) * | 1998-10-14 | 2000-04-20 | Vesuvius Crucible Company | Immersed pour tube having an erosion-resistant sleeve and method of manufacturing the same |
| US20050280192A1 (en) * | 2004-06-16 | 2005-12-22 | Graham Carson | Zirconia refractories for making steel |
| US8393183B2 (en) | 2007-05-07 | 2013-03-12 | Whirlpool Corporation | Fabric treatment appliance control panel and associated steam operations |
| CN111116195A (en) * | 2019-12-23 | 2020-05-08 | 江苏奥能耐火材料有限公司 | Immersion nozzle zirconium metal ceramic combined erosion-resistant material |
| CN111618288A (en) * | 2020-06-13 | 2020-09-04 | 泰州市旺鑫耐火材料有限公司 | Laminated connection ladder steel penetration-preventing water feeding port |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS583992B2 (en) * | 1974-11-30 | 1983-01-24 | ニホンルツボ カブシキガイシヤ | Lenzokuchiyuzoyoushinseki nozzle |
| DE2500478A1 (en) * | 1975-01-08 | 1976-07-15 | Didier Werke Ag | IMMERSION SPOUT FOR CONTINUOUS CASTING PLANTS |
| JPS591229B2 (en) * | 1978-04-26 | 1984-01-11 | 明知耐火煉瓦株式会社 | Immersion nozzle for continuous casting of molten steel |
| JPS54155124A (en) * | 1978-05-29 | 1979-12-06 | Toshiba Ceramics Co | Immersion nozzle for continuous steel casting |
| JPS5554244A (en) * | 1978-10-16 | 1980-04-21 | Nippon Rutsubo Kk | Two layer type immersion nozzle and production thereof |
-
1980
- 1980-08-07 JP JP10765680A patent/JPS5732858A/en active Pending
-
1981
- 1981-07-22 GB GB8122512A patent/GB2081702B/en not_active Expired
- 1981-07-22 ZA ZA815030A patent/ZA815030B/en unknown
- 1981-07-23 CA CA000382324A patent/CA1168019A/en not_active Expired
- 1981-07-24 AU AU73455/81A patent/AU544800B2/en not_active Ceased
- 1981-07-30 IT IT23265/81A patent/IT1138906B/en active
- 1981-08-03 KR KR1019810002814A patent/KR830005940A/en not_active Withdrawn
- 1981-08-05 BR BR8105045A patent/BR8105045A/en not_active IP Right Cessation
- 1981-08-05 DE DE3131068A patent/DE3131068C2/en not_active Expired
- 1981-08-05 BE BE0/205590A patent/BE889870A/en not_active IP Right Cessation
- 1981-08-07 FR FR8115371A patent/FR2488165A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| AU7345581A (en) | 1982-02-11 |
| IT1138906B (en) | 1986-09-17 |
| FR2488165A1 (en) | 1982-02-12 |
| FR2488165B1 (en) | 1983-12-02 |
| IT8123265A0 (en) | 1981-07-30 |
| GB2081702B (en) | 1984-10-31 |
| JPS5732858A (en) | 1982-02-22 |
| BR8105045A (en) | 1982-04-20 |
| BE889870A (en) | 1981-12-01 |
| KR830005940A (en) | 1983-09-14 |
| GB2081702A (en) | 1982-02-24 |
| ZA815030B (en) | 1982-07-28 |
| DE3131068A1 (en) | 1982-03-25 |
| AU544800B2 (en) | 1985-06-13 |
| DE3131068C2 (en) | 1983-11-24 |
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