CA1130983A - Method and apparatus for continuously casting molten metal - Google Patents
Method and apparatus for continuously casting molten metalInfo
- Publication number
- CA1130983A CA1130983A CA333,604A CA333604A CA1130983A CA 1130983 A CA1130983 A CA 1130983A CA 333604 A CA333604 A CA 333604A CA 1130983 A CA1130983 A CA 1130983A
- Authority
- CA
- Canada
- Prior art keywords
- molten metal
- mould
- vessel
- orifice
- casting
- 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
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
-
- 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
- B22D11/16—Controlling or regulating processes or operations
- B22D11/18—Controlling or regulating processes or operations for pouring
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
Abstract
TITLE
A METHOD AND APPARATUS FOR CONTINUOUSLY CASTING MOLTEN METAL
INVENTOR
ROBERT THOMSON
ABSTRACT
A method of continuously casting molten metal in a reciprocable mould sealed to a vessel containing liquid metal by means of an extendible container, wherein a tube forming a passage from an orifice in the vessel to the mould is sealed at one end to the vessel, and at the other end dips into molten metal in an entry to the mould. A meniscus of molten metal around the tube and in the mould is stabilized by adjusting the pressure of inert gas fed into the extendible container so that the rate of flow of metal from the vessel to the mould is controlled directly by the rate of extraction of the solidifying casting from the mould. The problems related to controlling metal flow into the mould are substan-tially reduced. This is of particular significance in continu-ous casting steel, permitting the casting rate to be indepen-dent of the size of the orifice in the vessel, and of the ferrostatic head above it. Thus it is possible to use a larger orifice in the vessel, alleviating the problem of nozzle blockage, and to continuously cast aluminum killed steels where deoxidation by and alloying of aluminum is achieved in the vessel or during prior refining stages of preparation of the molten metal.
A METHOD AND APPARATUS FOR CONTINUOUSLY CASTING MOLTEN METAL
INVENTOR
ROBERT THOMSON
ABSTRACT
A method of continuously casting molten metal in a reciprocable mould sealed to a vessel containing liquid metal by means of an extendible container, wherein a tube forming a passage from an orifice in the vessel to the mould is sealed at one end to the vessel, and at the other end dips into molten metal in an entry to the mould. A meniscus of molten metal around the tube and in the mould is stabilized by adjusting the pressure of inert gas fed into the extendible container so that the rate of flow of metal from the vessel to the mould is controlled directly by the rate of extraction of the solidifying casting from the mould. The problems related to controlling metal flow into the mould are substan-tially reduced. This is of particular significance in continu-ous casting steel, permitting the casting rate to be indepen-dent of the size of the orifice in the vessel, and of the ferrostatic head above it. Thus it is possible to use a larger orifice in the vessel, alleviating the problem of nozzle blockage, and to continuously cast aluminum killed steels where deoxidation by and alloying of aluminum is achieved in the vessel or during prior refining stages of preparation of the molten metal.
Description
This invention relates to a method and apparatus for continuously casting me-tal.
It has already been proposed in Unlted States Pa-tents Nos. 3,~02,757, dated Sep-tember 24, 1968, :t.M.D.
Halliday, and 3,840,062, dated October 8, 197~, M. P. Kenney, to provide a flexible chamber joined at one end to a tundish and at the other end to a mould capable of being reciprocated.
During casting, molten metal flows freely from an orifice in the tundish, down a central por-tion of the chamber bore and into the mould, while an inert gas blanket at atmospheric pressure or about 1.5 psi is circulated around the molten metal and in the chamber to exclude and remove oxycJen and ;' gases containing oxygen and thus inhibit oxide formation except as is incidental to the cooling and freezing of the metal in the mould itselE. In similar disclosures, by Schrage - U.S. Patent No. 3,563,299 dated Feb. 16, 1971 Pollard - U.S. Patent No. 4,023,61~ dated May 17, 1975 Kashuba - U.S. Patent No. 3,833,050 dated Sept. 3, 1974 and ~yman - U.S. Patent No. 3,572,422 dated March 23, 1971 contained and purging gases at slightly above atmospheric pressure are introduced on and around the free-falling pouring stream of metal to minimize re-oxidation of the metal.
Whi~e these proposals may overcome the problems of oxidation of the pouring stream, a problem still exists in that the orifice in the tundish has to be suf~
ciently small in the cross-section to control the rate of volumetric flow of liquid metal into the mould to match the rate of casting from the mould, and this small size range of orifice, for example between 9.5 mm and 25.4 mm diameter J makes the orifice highly susceptible to partial or complete blocking by aluminous deposits from the metal, necessitating frequent shut-downs, or, the elimination of those elements inducing . ~ ~
~3~g~3~
blocking (Al, Ti, Zr, etc.) from the pre-treatment procedures used to refine the li~uid metal.
It would be desirable to provide a me-thod of continuously casting molten metal wherein the rate of volumetric flo~ of the liquid metal into the mould is not .controlled by the cross-sectional area of. the orifice in the tundish because this would allow an orifice of greater cross-section to be used and thus alleviate the problem associated with partial blocking of the orifice.
According to the present invention there is provided in the method of continuously casting aluminum killed steels and alloys, as molten metal,by causing the molten metal to flow, by means of a static head of molten metal in a vessel, rom an outlet orifice in the vessel into a reciprocable mould through an extendible chamber shrouding the path o~ the pouring molten me-tal and sealing the vessel to the mould, while inert gas is being fed into the extendible chamber~ and which includes, a) causing the molten me-tal flowing through the ~0 vessel outlet orifice to flow through a tube of refractory material in the extendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifice and the other end immersed in molten metal in an entry to the mould with a meniscus of molten metal in the entry to the mould and around the tube, and b) supporting a static head of molten metal in the vessel and the tube, by means of the pressure of pressurized inert gas in the e~tendible chamber and on the meniscus of molten metal, to maintain the tube filled with molten metal flowing substantially at the same volumetric rate as the casting rate in the mould, the improvement comprising, c) the outlet orifice has a diameter greater
It has already been proposed in Unlted States Pa-tents Nos. 3,~02,757, dated Sep-tember 24, 1968, :t.M.D.
Halliday, and 3,840,062, dated October 8, 197~, M. P. Kenney, to provide a flexible chamber joined at one end to a tundish and at the other end to a mould capable of being reciprocated.
During casting, molten metal flows freely from an orifice in the tundish, down a central por-tion of the chamber bore and into the mould, while an inert gas blanket at atmospheric pressure or about 1.5 psi is circulated around the molten metal and in the chamber to exclude and remove oxycJen and ;' gases containing oxygen and thus inhibit oxide formation except as is incidental to the cooling and freezing of the metal in the mould itselE. In similar disclosures, by Schrage - U.S. Patent No. 3,563,299 dated Feb. 16, 1971 Pollard - U.S. Patent No. 4,023,61~ dated May 17, 1975 Kashuba - U.S. Patent No. 3,833,050 dated Sept. 3, 1974 and ~yman - U.S. Patent No. 3,572,422 dated March 23, 1971 contained and purging gases at slightly above atmospheric pressure are introduced on and around the free-falling pouring stream of metal to minimize re-oxidation of the metal.
Whi~e these proposals may overcome the problems of oxidation of the pouring stream, a problem still exists in that the orifice in the tundish has to be suf~
ciently small in the cross-section to control the rate of volumetric flow of liquid metal into the mould to match the rate of casting from the mould, and this small size range of orifice, for example between 9.5 mm and 25.4 mm diameter J makes the orifice highly susceptible to partial or complete blocking by aluminous deposits from the metal, necessitating frequent shut-downs, or, the elimination of those elements inducing . ~ ~
~3~g~3~
blocking (Al, Ti, Zr, etc.) from the pre-treatment procedures used to refine the li~uid metal.
It would be desirable to provide a me-thod of continuously casting molten metal wherein the rate of volumetric flo~ of the liquid metal into the mould is not .controlled by the cross-sectional area of. the orifice in the tundish because this would allow an orifice of greater cross-section to be used and thus alleviate the problem associated with partial blocking of the orifice.
According to the present invention there is provided in the method of continuously casting aluminum killed steels and alloys, as molten metal,by causing the molten metal to flow, by means of a static head of molten metal in a vessel, rom an outlet orifice in the vessel into a reciprocable mould through an extendible chamber shrouding the path o~ the pouring molten me-tal and sealing the vessel to the mould, while inert gas is being fed into the extendible chamber~ and which includes, a) causing the molten me-tal flowing through the ~0 vessel outlet orifice to flow through a tube of refractory material in the extendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifice and the other end immersed in molten metal in an entry to the mould with a meniscus of molten metal in the entry to the mould and around the tube, and b) supporting a static head of molten metal in the vessel and the tube, by means of the pressure of pressurized inert gas in the e~tendible chamber and on the meniscus of molten metal, to maintain the tube filled with molten metal flowing substantially at the same volumetric rate as the casting rate in the mould, the improvement comprising, c) the outlet orifice has a diameter greater
2 -~13~ 3 than 31.7 mm, and d~ the casting rate ls controlled substantially by the volume-tric rate of extraction o~ product from:the reciprocable mould.
~
~ ~ .
.. .
Further according to the present inven-tion there is provided in the combination o~ apparatus for continuously casting aluminum killed steels an~ alloys, as molten metal comprising,a vessel for the molten metal, the vessel having an outlet orifice for molten metal to flow therethrough from the vessel under a static head, a recip-rocable mould for receiving the molten metal when it is flowing through the outlet orifice, an extendible chamber shrouding the path for the flowing molten metal and sealed to the vessel and the mould, and means for feeding pressurized inert gas into the chamber, and wherein there is provided, a) a molten m~tal static head containing tube of refractory material in the extendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifi.ce, for receiving the molten metal when it is flowing therethrough, and the other end positioned or immersion in molten metal in an en.try to the mould with a meniscus of molten metal therearound in the entry to the mould, and 2r) b) means for adjusting the pressure of the inert gas feed to the extendible chamber for, in operation, support-ing a static head of molten metal in the vessel by the pressure of the inert gas on the meniscus of molten metal, whereby, in operation c) the tube is maintained filled with molten metal flowing therein substantially at the same volumetric rate as the casting ratP in the mould, the improvement comprising, d) the orifice has a diameter greater than 31~7 mm, whereby e) the casting rate may be controlled substantially by the volumetric rate of extraction of product from the reciprocable mould~
A ~ 3 113~ 3 In the accompanying drawings whlch illustrate prior art and, by way of example, embodiments of the present invention:
Figure 1 is a diagrammatic, sectional side view of portions of conventional apparatus for continuously /
' /
~`'. .
9~33 casting molten metal, and Figure 2 is a diagrammatic, sectional side view of portions of an apparatus according -to the present inven-tion for continuously casting molten metal.
In Figure l there is shown an apparatus for contin-uously casting molten metal comprising a vessel l for molten metal 2, the vessel having an outlet orifice 4 for molten metal 6 to flow therethrough from the vessel 1 under a static head, a reciprocable r cooled mould 8 of known type for receiving the molten meta~ 6 when it is 10wing through the outlet orifice 4, an extendible chamber 10 shrouding the path for the flowing molten metal 6 and sealed to the vessel 1 and the mould 8, and means 12 and 13 for feeding pressurized inert gas to thè chamber lO.
In operation, molten metal ~lows from the vessel l through the outlet orifice 4, as a xee-falling stream of molten metal 6, into the mould 8 where it is continuously cast into a rod and pulled therefrom by a conventional extrac~
tion device ~not shown). Pressurized inert gas, e.~. nitro-gen, at slightly above atmospheric pressure, is fed into the chamber lO to blanket the stream o molten metal 6 from atmos-pheric oxygen and minimize re-oxidation oE the molten metal 6.
The free-falling stream of molten metal 6 exits from the vessel 1 through an orifice 4, the cross-sectional area of which is governed by the rate of flow of metal therethrough having to match the rate at which metal is cast in the mould 8. This results in the cross-sectional area of the orifice 4 being small enough to be subject to blocking by oxides being deposited therein.
3n Referring now to Figure 2, similar parts to those shown in Figure l are designated by the same reference numerals and the previous description is relied upon to describe them.
:~3~9~3 In this embodiment the outlet orifice 4 has a oriEice diameter greater than 31.7 mm and is located above a sliding ceramic plate 14 which is a gate of a type of gate valve known in the art as a slide gate 16. The function of the slide gate 16 is to close off and open the path from the orifice 4 to the mould 8. A molten metal head containing tube 18 of refractory material is in the extendible chamber 10. The tube 18 has one end 20 sealed to a portion of the vessel 1 extending around the orifice 4 via the slide gate 16, for receiving molten metal 6 when it is flowing through the orifice 4, and has t~e other end 22 positioned for immersion in molten metal 24 in an entry 26 to the mould 8 with a meniscus 28 of molten metal therearound in the entry 26 to the mould 8.
The extendible chamber 10 comprises a 1exible bellows sealed to the vessel 1 and to the mould 8 by gaskets 30 and 32 respectively. The means 12 for feeding pressurized inert gas into the chamber 10 is provided with a solenoid valve 34. An inert gas outlet 36 is provided for the chamber 10 and the outlet 36 has a solenoid:valve 38. The tube 18 is preferably made of a refractory material of high thermal shock resistance such as fused silica or graphitized alumina marketed by Vesuvius Crucible Company o Pittsburg, U. S. A.
The end 22 of the tube 18 preferably extends into the molten metal 24 to a depth in the range 25 mm to 50 mm.
The level of the meniscus 28 may be detected ~y one of several known detection means, e.g. by using a y-ray source 40 and detector 42 external to the mould 8, or by thermo-couples 44 embedded in the mould 8, and such level detection means,are usbd to automatically control, via solenoid valves 34 and 38 the absolute gas pressure in the extendible chamber 10, by admittîng inert gas through valve 34 from a pressurized inert gas source (not shown) when the level of the meniscus 28 ~13 ~`
- ~IL13~33 rises too high, and by opening valve 38 to release inert gas from the extendible chamber 10 to a low pressure chamber (not shown) or to atmosphere when the level of the meniscus 28 is detected as being below a desired level, In this manner the ferrostatic head 'h' cf molten metal 6 in the vessel 1 and the tube 18 may be continually and automatically more or less balanced by the pressure of enclosed gas acting on the meniscus 28.
In practice the controlled pressure of the inert gas in the extendible chamber 10 is subjected to disturbance by the heating effe'ct on the inert gas of molten metal 6 passing through the tube 18, and by the compression/expansion effect occasioned by the reciprocating action of the recipro-cable mould. In this embodiment these disturbances are corrected or by incorporating in the pressure control system a sensitive pressure transducer 46, from which a time derivative signal is obtained dt and used to actuate valves 34 or 38 in anticipation of pressure fluctuations of the înert gas from the inert gas pressure determined by the meniscus level detection means. In this manner any cyclic variation in pressure of the inert gas from the mean pressure, or the drift of pressure away from the mean pressure, are both adequately negated. In a likewise manner, the above mentioned pressure control system automatically adjusts the absolute pressure of gas at the meniscus to compensate for changes in Dh" occurring as the level of the molten metal 2 in the vessel 1 changes during the course of casting, i.e.
decreases during casting, or increases b~ additional molten metal being supplied to vessel 1~
The tube 18 is maintained filled with molten metal flowing therein subst:antially at the same volumetric rate as the casting rate from the mould 8, and such flow is controlled ~13~83 sole].y by the volumetric rate of extraction of product from the mould 8.
The reciprocable mould 8 is a known -type of mould which may be reciprocated in relation to the casting during opera-tion.
The extendible chamber 10 comprises a cylindrical section 48, a bellows section 50 and a disc-shaped end wall 5~, with sealed flanges.
In the embodiment in Figure 2 the bore of the tube 18 is shown of constant cross-section, but in other embodiments of this invention the tube 18 may be any suitable shape that is appropriate to the size and shape of the product being cast.
Thus the present inven-tion is not restricted to us.Lng tubes 18 having bores of constant cross~section but includes tubes 18 having for example, a funnel shape bore wh.ich rnay be round or rectilinear in cross-section.
In operation, molten metal, e.g. molten steel r is continuously cast by introducing the molten metal 2, by means of the static head "h1' of molten metal, from the outlet orifice 4 in the vessel 1 into the reciprocable mould 8 through tube 18 in the extendible chamber 10, shroudin~
the path of molten metal 6 and sealiny the vessel 1 to the mou].d 8, while inert gas, e.g. nitrogenr is being fed by ~he feed pipe 12 into the extendible chamber 10 at a suitable pressure for the inert gas pressure "P" on the meniscus 28 to maintain tne tube 18 filled with molten metal 6 flowing substantially at the same volumetric rate as the casting rate in the mould 8.
In order to maintain the meniscus 28 of molten metal in the entry portion of the mould 8 and around the end of the tube 18 as the mould 8 reciprocates about a mean position the fluctuations in pressure in the extendible chamber 10 ~L3~3 induced by such reciprocation of the mould 8 may be compensated for by actua-ting the solenoid valves 34 and 38 in response to movements of the reciprocable mould 8~ A different means of maintaining a predetermined gas pressure in the extendible chamber 10 comprises incorporating in the wall of the extendible chamber 10 a different bellows design to that shown in Figure 2 and designated 50. The different bellows having the characteristic that the volume enclosed by the bellows is at all times substantially constant irrespective of the degree of compression or expansion of the bellows within the limits set by the reciprocation of the mould 8. This substantially constant volume ~haracter-istic may be achieved by constructing triangulated segments of the bellows wall oE an elastic heat resistant material/ as, for example, certain high temperature polymeric materials.
Through these, and possibly other means known in the art, the variations in pressure in the chamber, due to the piston-like movemenk of the mould 8, may be substantially reduced to produce an acceptably small oscillation of the level of the meniscus 28. In practice, such permissible ~ariations in the level of the meniscus 28 will be in the range of ~0.125 to ~0.25 ins. (~3 m.m. to ~ 6 m.m.).
When molten steel is being cast, the pressure P psi in terms of "h'l ins. may be expressed as P = 14.7 ~ 0.27 h with P controlled to ~0.1 psi.
In existing continuous casting machine designs for steel casting, to which machines embodiments of the present invention may be added with a minimum of disturbance of existing equipment and practices, the distance "h", ma~ be of the order of 25 to 50 ins. (63.5 to 127 cm~. Thus the incorporation of the proposed improved method wou:Ld require absolute enclosure pressures in the range 20 to 28 psi ~13~ 33 approxîmately.
By the present invention, it is possible to cast from the vessel 1, grades of steels and alloys which are aluminum killed or deoxidized at some previous stage of metal preparation, and it is no longer necessary to add aluminum directly into the mould 8. The reason why mol-ten aluminum killed steels can be cast by~the present invention in this manner is because a much larger orifice 4 can be used, i.e. a size of orifice 4 can be used which will not be susceptible to blocking by deposition of aluminous inclu-sions on its walls. By way of example of this, it is well known in the art that an aluminum treated steel in the vessel 1 having a residual aluminum level of O.Q4 wt. per cent will cause blocking of the orifice 4 unless the diameter of the latter is greater than around 1~ ins. (31.7 mm).
The free flowing delivery rate of steel, flowing under gravit~, is so great through an orifice of this size that prior to the present invention only very large slabs could be cast of aluminum bearing steels. By contrast, the smaller nozzle orifices of 0.625 (41.3 mm) in diameter used prior to the invention to control liquid metal 1OW
in casting smaller billets in the size range 4 x 4 in.
(10.2 x 10.2 cm) to 6 x 6 in. (15.2 x 15.2 cm) would block the orifice 4 quickly if aluminum treated steel was used in the vessel 1. Since with the present invention, neither the size of the orifice 4 nor the pressure of the gas in the extendible chamber 10 controls molten metal flow, it is possible to use a larger orifice 4 than could _ g _ : ' ~13~33 previously be used so that the accwmulation of aluminous oxides in the orifice 4 is tolerable, and cannot attain such a severity as to completely block the larger orifice 4. Partial blocking of the orifice 4, which pre-viously catastrophically reduced the rate of flow of mol~en metal from the vessel 1 through the orifice 4 to the mould 8, is no longer of any consequence since the flow of li~uld metal through a part1ally blocked larger oriflce 4 is adequate for small to medium billet sizes and is controlled solely by the rate of removal of the semi-solid casting from the mould 8.
Thus the main advantacJes of the present invention can be sùmmarized as ~ollows:
1.) An orifice of larger diameter that previousl~
and not susceptible to blockage of the orifice 4 can be used to cast the smallest sizes of billets of commercial interest from fully deoxidized steels and steel alloys -contained, in vessel 1, for example, from steels which have been pre-alloyed with ~uantities of Al, Ti, Zr, B, N. etc.
2.) The casting rate is a separate controllable parameter in the process, and is no longer, as with prior process, dependent on the size of the orifice 4. In the prior art the rate of flow of metal through the orifice 4 directly determined the casting rate of product leaving the mould 8. With the present invention, the operator-chosen casting rate of product determines the rate of flow of liquid metal through the orifice 4.
-- 10 -- !
~
~ ~ .
.. .
Further according to the present inven-tion there is provided in the combination o~ apparatus for continuously casting aluminum killed steels an~ alloys, as molten metal comprising,a vessel for the molten metal, the vessel having an outlet orifice for molten metal to flow therethrough from the vessel under a static head, a recip-rocable mould for receiving the molten metal when it is flowing through the outlet orifice, an extendible chamber shrouding the path for the flowing molten metal and sealed to the vessel and the mould, and means for feeding pressurized inert gas into the chamber, and wherein there is provided, a) a molten m~tal static head containing tube of refractory material in the extendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifi.ce, for receiving the molten metal when it is flowing therethrough, and the other end positioned or immersion in molten metal in an en.try to the mould with a meniscus of molten metal therearound in the entry to the mould, and 2r) b) means for adjusting the pressure of the inert gas feed to the extendible chamber for, in operation, support-ing a static head of molten metal in the vessel by the pressure of the inert gas on the meniscus of molten metal, whereby, in operation c) the tube is maintained filled with molten metal flowing therein substantially at the same volumetric rate as the casting ratP in the mould, the improvement comprising, d) the orifice has a diameter greater than 31~7 mm, whereby e) the casting rate may be controlled substantially by the volumetric rate of extraction of product from the reciprocable mould~
A ~ 3 113~ 3 In the accompanying drawings whlch illustrate prior art and, by way of example, embodiments of the present invention:
Figure 1 is a diagrammatic, sectional side view of portions of conventional apparatus for continuously /
' /
~`'. .
9~33 casting molten metal, and Figure 2 is a diagrammatic, sectional side view of portions of an apparatus according -to the present inven-tion for continuously casting molten metal.
In Figure l there is shown an apparatus for contin-uously casting molten metal comprising a vessel l for molten metal 2, the vessel having an outlet orifice 4 for molten metal 6 to flow therethrough from the vessel 1 under a static head, a reciprocable r cooled mould 8 of known type for receiving the molten meta~ 6 when it is 10wing through the outlet orifice 4, an extendible chamber 10 shrouding the path for the flowing molten metal 6 and sealed to the vessel 1 and the mould 8, and means 12 and 13 for feeding pressurized inert gas to thè chamber lO.
In operation, molten metal ~lows from the vessel l through the outlet orifice 4, as a xee-falling stream of molten metal 6, into the mould 8 where it is continuously cast into a rod and pulled therefrom by a conventional extrac~
tion device ~not shown). Pressurized inert gas, e.~. nitro-gen, at slightly above atmospheric pressure, is fed into the chamber lO to blanket the stream o molten metal 6 from atmos-pheric oxygen and minimize re-oxidation oE the molten metal 6.
The free-falling stream of molten metal 6 exits from the vessel 1 through an orifice 4, the cross-sectional area of which is governed by the rate of flow of metal therethrough having to match the rate at which metal is cast in the mould 8. This results in the cross-sectional area of the orifice 4 being small enough to be subject to blocking by oxides being deposited therein.
3n Referring now to Figure 2, similar parts to those shown in Figure l are designated by the same reference numerals and the previous description is relied upon to describe them.
:~3~9~3 In this embodiment the outlet orifice 4 has a oriEice diameter greater than 31.7 mm and is located above a sliding ceramic plate 14 which is a gate of a type of gate valve known in the art as a slide gate 16. The function of the slide gate 16 is to close off and open the path from the orifice 4 to the mould 8. A molten metal head containing tube 18 of refractory material is in the extendible chamber 10. The tube 18 has one end 20 sealed to a portion of the vessel 1 extending around the orifice 4 via the slide gate 16, for receiving molten metal 6 when it is flowing through the orifice 4, and has t~e other end 22 positioned for immersion in molten metal 24 in an entry 26 to the mould 8 with a meniscus 28 of molten metal therearound in the entry 26 to the mould 8.
The extendible chamber 10 comprises a 1exible bellows sealed to the vessel 1 and to the mould 8 by gaskets 30 and 32 respectively. The means 12 for feeding pressurized inert gas into the chamber 10 is provided with a solenoid valve 34. An inert gas outlet 36 is provided for the chamber 10 and the outlet 36 has a solenoid:valve 38. The tube 18 is preferably made of a refractory material of high thermal shock resistance such as fused silica or graphitized alumina marketed by Vesuvius Crucible Company o Pittsburg, U. S. A.
The end 22 of the tube 18 preferably extends into the molten metal 24 to a depth in the range 25 mm to 50 mm.
The level of the meniscus 28 may be detected ~y one of several known detection means, e.g. by using a y-ray source 40 and detector 42 external to the mould 8, or by thermo-couples 44 embedded in the mould 8, and such level detection means,are usbd to automatically control, via solenoid valves 34 and 38 the absolute gas pressure in the extendible chamber 10, by admittîng inert gas through valve 34 from a pressurized inert gas source (not shown) when the level of the meniscus 28 ~13 ~`
- ~IL13~33 rises too high, and by opening valve 38 to release inert gas from the extendible chamber 10 to a low pressure chamber (not shown) or to atmosphere when the level of the meniscus 28 is detected as being below a desired level, In this manner the ferrostatic head 'h' cf molten metal 6 in the vessel 1 and the tube 18 may be continually and automatically more or less balanced by the pressure of enclosed gas acting on the meniscus 28.
In practice the controlled pressure of the inert gas in the extendible chamber 10 is subjected to disturbance by the heating effe'ct on the inert gas of molten metal 6 passing through the tube 18, and by the compression/expansion effect occasioned by the reciprocating action of the recipro-cable mould. In this embodiment these disturbances are corrected or by incorporating in the pressure control system a sensitive pressure transducer 46, from which a time derivative signal is obtained dt and used to actuate valves 34 or 38 in anticipation of pressure fluctuations of the înert gas from the inert gas pressure determined by the meniscus level detection means. In this manner any cyclic variation in pressure of the inert gas from the mean pressure, or the drift of pressure away from the mean pressure, are both adequately negated. In a likewise manner, the above mentioned pressure control system automatically adjusts the absolute pressure of gas at the meniscus to compensate for changes in Dh" occurring as the level of the molten metal 2 in the vessel 1 changes during the course of casting, i.e.
decreases during casting, or increases b~ additional molten metal being supplied to vessel 1~
The tube 18 is maintained filled with molten metal flowing therein subst:antially at the same volumetric rate as the casting rate from the mould 8, and such flow is controlled ~13~83 sole].y by the volumetric rate of extraction of product from the mould 8.
The reciprocable mould 8 is a known -type of mould which may be reciprocated in relation to the casting during opera-tion.
The extendible chamber 10 comprises a cylindrical section 48, a bellows section 50 and a disc-shaped end wall 5~, with sealed flanges.
In the embodiment in Figure 2 the bore of the tube 18 is shown of constant cross-section, but in other embodiments of this invention the tube 18 may be any suitable shape that is appropriate to the size and shape of the product being cast.
Thus the present inven-tion is not restricted to us.Lng tubes 18 having bores of constant cross~section but includes tubes 18 having for example, a funnel shape bore wh.ich rnay be round or rectilinear in cross-section.
In operation, molten metal, e.g. molten steel r is continuously cast by introducing the molten metal 2, by means of the static head "h1' of molten metal, from the outlet orifice 4 in the vessel 1 into the reciprocable mould 8 through tube 18 in the extendible chamber 10, shroudin~
the path of molten metal 6 and sealiny the vessel 1 to the mou].d 8, while inert gas, e.g. nitrogenr is being fed by ~he feed pipe 12 into the extendible chamber 10 at a suitable pressure for the inert gas pressure "P" on the meniscus 28 to maintain tne tube 18 filled with molten metal 6 flowing substantially at the same volumetric rate as the casting rate in the mould 8.
In order to maintain the meniscus 28 of molten metal in the entry portion of the mould 8 and around the end of the tube 18 as the mould 8 reciprocates about a mean position the fluctuations in pressure in the extendible chamber 10 ~L3~3 induced by such reciprocation of the mould 8 may be compensated for by actua-ting the solenoid valves 34 and 38 in response to movements of the reciprocable mould 8~ A different means of maintaining a predetermined gas pressure in the extendible chamber 10 comprises incorporating in the wall of the extendible chamber 10 a different bellows design to that shown in Figure 2 and designated 50. The different bellows having the characteristic that the volume enclosed by the bellows is at all times substantially constant irrespective of the degree of compression or expansion of the bellows within the limits set by the reciprocation of the mould 8. This substantially constant volume ~haracter-istic may be achieved by constructing triangulated segments of the bellows wall oE an elastic heat resistant material/ as, for example, certain high temperature polymeric materials.
Through these, and possibly other means known in the art, the variations in pressure in the chamber, due to the piston-like movemenk of the mould 8, may be substantially reduced to produce an acceptably small oscillation of the level of the meniscus 28. In practice, such permissible ~ariations in the level of the meniscus 28 will be in the range of ~0.125 to ~0.25 ins. (~3 m.m. to ~ 6 m.m.).
When molten steel is being cast, the pressure P psi in terms of "h'l ins. may be expressed as P = 14.7 ~ 0.27 h with P controlled to ~0.1 psi.
In existing continuous casting machine designs for steel casting, to which machines embodiments of the present invention may be added with a minimum of disturbance of existing equipment and practices, the distance "h", ma~ be of the order of 25 to 50 ins. (63.5 to 127 cm~. Thus the incorporation of the proposed improved method wou:Ld require absolute enclosure pressures in the range 20 to 28 psi ~13~ 33 approxîmately.
By the present invention, it is possible to cast from the vessel 1, grades of steels and alloys which are aluminum killed or deoxidized at some previous stage of metal preparation, and it is no longer necessary to add aluminum directly into the mould 8. The reason why mol-ten aluminum killed steels can be cast by~the present invention in this manner is because a much larger orifice 4 can be used, i.e. a size of orifice 4 can be used which will not be susceptible to blocking by deposition of aluminous inclu-sions on its walls. By way of example of this, it is well known in the art that an aluminum treated steel in the vessel 1 having a residual aluminum level of O.Q4 wt. per cent will cause blocking of the orifice 4 unless the diameter of the latter is greater than around 1~ ins. (31.7 mm).
The free flowing delivery rate of steel, flowing under gravit~, is so great through an orifice of this size that prior to the present invention only very large slabs could be cast of aluminum bearing steels. By contrast, the smaller nozzle orifices of 0.625 (41.3 mm) in diameter used prior to the invention to control liquid metal 1OW
in casting smaller billets in the size range 4 x 4 in.
(10.2 x 10.2 cm) to 6 x 6 in. (15.2 x 15.2 cm) would block the orifice 4 quickly if aluminum treated steel was used in the vessel 1. Since with the present invention, neither the size of the orifice 4 nor the pressure of the gas in the extendible chamber 10 controls molten metal flow, it is possible to use a larger orifice 4 than could _ g _ : ' ~13~33 previously be used so that the accwmulation of aluminous oxides in the orifice 4 is tolerable, and cannot attain such a severity as to completely block the larger orifice 4. Partial blocking of the orifice 4, which pre-viously catastrophically reduced the rate of flow of mol~en metal from the vessel 1 through the orifice 4 to the mould 8, is no longer of any consequence since the flow of li~uld metal through a part1ally blocked larger oriflce 4 is adequate for small to medium billet sizes and is controlled solely by the rate of removal of the semi-solid casting from the mould 8.
Thus the main advantacJes of the present invention can be sùmmarized as ~ollows:
1.) An orifice of larger diameter that previousl~
and not susceptible to blockage of the orifice 4 can be used to cast the smallest sizes of billets of commercial interest from fully deoxidized steels and steel alloys -contained, in vessel 1, for example, from steels which have been pre-alloyed with ~uantities of Al, Ti, Zr, B, N. etc.
2.) The casting rate is a separate controllable parameter in the process, and is no longer, as with prior process, dependent on the size of the orifice 4. In the prior art the rate of flow of metal through the orifice 4 directly determined the casting rate of product leaving the mould 8. With the present invention, the operator-chosen casting rate of product determines the rate of flow of liquid metal through the orifice 4.
-- 10 -- !
3~33 3.) Using an inert gas in the extendible chamber 10 at ~ 25 psi prevents any ingress of atmospheric oxygell and therefore eliminates o~idation of the metal between the vessel 1 and the mould 8.
4.~ The pressure exerted on the meniscus 28 by the inert gas above it in the extendible chamber 10 will be advantageous in improving the heat transfer between the outer surface of the solidifying casting and the wall of the mould 8. This advantage arises because the natural tendency of the hot solidified shell of the casting to contract and shrink away from the wall of the mould 8 will be resisted by the increased hydrostatic forces of the molten metal acting on the wall of the mould 8 from the li~uid metal inkerior, and tending to bulge the solidifyiny shell outward toward the wall o the mould 8. As is well appreciated in the art, any decrease in the air-gap between the wall of the mould 8 and the surface of the molten metal being cast such as that obtained by the present invention by pressurization of the liquid core of the casting, will increase the rate of heat transfer between the molten metal being cast and the mould 8, producing greater solidification rates in the casting.
Thus by producing greater solidification rates, the present invention will permit significantly advantageous lncreases in casting rate of all products, whether aluminum treated or not.
Another advantage of the present invention relates to the problem in the art of providing efficient lubrication of the wall of the mould 8 to prevent the newly formed, moving casting skin sticking to and tearing on the wall of the mould 8. Thj.s undesirable phenomenon of mould-casting 9~3 interEacial fric-tion is kept under control in the art by continuously introducing an oil film Gn the wall of the mould 8 above the meniscus 28 of molten me-tal. In the prior art, capillary forces and gravity have caused the oil film to spread downwards past the meniscal line into the area of mould-cas-ting contact. In the present invention this spreading of the lubricant downwards is considerably and advantayeously enhanced by the effect of the pressurized inert gas above the meniscus 28, forcing oil down the wall of the mould 8 into the lower reaches of the wall of the mould 8, which are, of coursel at atmospheric pressure only.
In addition to improving operational aspects of continuous casting aluminum deoxidized steels by improving castin~ rate and decreasing mould-billet friction~ the present invention has the additional advantage o widely incxeasing the acceptable range of casting temperature of metal which can be used, since the rate of casting is now an ind~pendent ~ariable. This may be explained by the following generalized description of the prior art and the possibilities inherent in the present invention. In the prior art, the optimum casting rate (Vo) is associated and determined by the heat transfer characteristics of the mould 8, (Ho)/ and the optimum metal superheat (To). The diameter of the oriice 4 that is used is precisely that which will supply the liquid metal at a volumetric flow rate (Vo) at superheat ~To). Let the diameter of the orifice 4 be (Do). All of these parameters, in the prior art, are inter-dependent, and a variation of one of them outside narrow limits will cause failure of the process~ For example if the superheat ~To~ falls to ~T)~
(To > T,~ the fluidity of the steel through the orifice 4 having a diameter tDo) is reduced and ~Vo) decreases to (V1)O In one ex~reme~ with ~T <<To), for example, for steel (To - T > 100 C) the thermal losses at -the orifice 4 may - 12 _ 3L~ 9i~33 may cause complete closure of the orifice 4 and a cessation of pouring and cas-ting. ~-t the other extreme, if the superheat (To) is greater than optimum, (T > To), the rate of flow through the orifice 4 having a diameter (Do) will be slightly increased, but more importantly the dwell time of metal in the heat exchange zone of the mould 8, now operating at (Ho~ or slightly higher, will not be long enough to dissipate the extra superheat, and less solidi-fication will occur, so that an inadequately thickenecl ingot 1~ shell is formed which will rupture at the exit of the mould 8 and a break-out of molten metal will occur. This cannot be avoided by reducing (Vo) since.(Vo) is conditioned solely by (Do). Thus in practice~ excursions of liquid metal superheat from (To) can lead to proc~ss f~ilure with the prior art.
Witk the present invention, a wide range of values of (To), (Do) and (Ho), and (Vo) can be usefully combined to greatly reduce system stoppages. (V~ can be varied independently of (Do), so that for example if the superheat of the molten metal is higher than what was optimum by known process, then (V) can be unilaterally reduced to afford the metal sufficient dwell time in the mould 8 to form a safe, solidified shell at the exit of the mould 8 which will not rupture. If the superheat (To) is less than optimum, then no longer does a small orifice 4 cause flow stoppage, because, with the present invention, the orifice diameter (Do) can be made many times greater in magnitude than the cross-sectional area of the orifices 4 of the prior art~
In summary then, a useful advantage of the present invention is -to permit the successful continuous cas-ting of bodies of liquid metal having a wider range of casting temperatures than could be used hitherto. Furthermore, with the prior art only small variations in orifice diameter r (Do), are permissible because a reduction in ~Do) due to nozzle blockage, or increase in (Do) by nozzle erosion, will both directly affect the casting rate and interfere with the con-tinuity of the casting process. With the present invention, the orifice size ~Do) is of minor or negligible significance to the operation of the process.
~.
- ~ 1~ '--
Thus by producing greater solidification rates, the present invention will permit significantly advantageous lncreases in casting rate of all products, whether aluminum treated or not.
Another advantage of the present invention relates to the problem in the art of providing efficient lubrication of the wall of the mould 8 to prevent the newly formed, moving casting skin sticking to and tearing on the wall of the mould 8. Thj.s undesirable phenomenon of mould-casting 9~3 interEacial fric-tion is kept under control in the art by continuously introducing an oil film Gn the wall of the mould 8 above the meniscus 28 of molten me-tal. In the prior art, capillary forces and gravity have caused the oil film to spread downwards past the meniscal line into the area of mould-cas-ting contact. In the present invention this spreading of the lubricant downwards is considerably and advantayeously enhanced by the effect of the pressurized inert gas above the meniscus 28, forcing oil down the wall of the mould 8 into the lower reaches of the wall of the mould 8, which are, of coursel at atmospheric pressure only.
In addition to improving operational aspects of continuous casting aluminum deoxidized steels by improving castin~ rate and decreasing mould-billet friction~ the present invention has the additional advantage o widely incxeasing the acceptable range of casting temperature of metal which can be used, since the rate of casting is now an ind~pendent ~ariable. This may be explained by the following generalized description of the prior art and the possibilities inherent in the present invention. In the prior art, the optimum casting rate (Vo) is associated and determined by the heat transfer characteristics of the mould 8, (Ho)/ and the optimum metal superheat (To). The diameter of the oriice 4 that is used is precisely that which will supply the liquid metal at a volumetric flow rate (Vo) at superheat ~To). Let the diameter of the orifice 4 be (Do). All of these parameters, in the prior art, are inter-dependent, and a variation of one of them outside narrow limits will cause failure of the process~ For example if the superheat ~To~ falls to ~T)~
(To > T,~ the fluidity of the steel through the orifice 4 having a diameter tDo) is reduced and ~Vo) decreases to (V1)O In one ex~reme~ with ~T <<To), for example, for steel (To - T > 100 C) the thermal losses at -the orifice 4 may - 12 _ 3L~ 9i~33 may cause complete closure of the orifice 4 and a cessation of pouring and cas-ting. ~-t the other extreme, if the superheat (To) is greater than optimum, (T > To), the rate of flow through the orifice 4 having a diameter (Do) will be slightly increased, but more importantly the dwell time of metal in the heat exchange zone of the mould 8, now operating at (Ho~ or slightly higher, will not be long enough to dissipate the extra superheat, and less solidi-fication will occur, so that an inadequately thickenecl ingot 1~ shell is formed which will rupture at the exit of the mould 8 and a break-out of molten metal will occur. This cannot be avoided by reducing (Vo) since.(Vo) is conditioned solely by (Do). Thus in practice~ excursions of liquid metal superheat from (To) can lead to proc~ss f~ilure with the prior art.
Witk the present invention, a wide range of values of (To), (Do) and (Ho), and (Vo) can be usefully combined to greatly reduce system stoppages. (V~ can be varied independently of (Do), so that for example if the superheat of the molten metal is higher than what was optimum by known process, then (V) can be unilaterally reduced to afford the metal sufficient dwell time in the mould 8 to form a safe, solidified shell at the exit of the mould 8 which will not rupture. If the superheat (To) is less than optimum, then no longer does a small orifice 4 cause flow stoppage, because, with the present invention, the orifice diameter (Do) can be made many times greater in magnitude than the cross-sectional area of the orifices 4 of the prior art~
In summary then, a useful advantage of the present invention is -to permit the successful continuous cas-ting of bodies of liquid metal having a wider range of casting temperatures than could be used hitherto. Furthermore, with the prior art only small variations in orifice diameter r (Do), are permissible because a reduction in ~Do) due to nozzle blockage, or increase in (Do) by nozzle erosion, will both directly affect the casting rate and interfere with the con-tinuity of the casting process. With the present invention, the orifice size ~Do) is of minor or negligible significance to the operation of the process.
~.
- ~ 1~ '--
Claims (2)
1. In the method of continuously casting aluminum killed steels and alloys, as molten metal, by pouring the molten metal, by means of a static head of molten metal in a vessel, from an outlet orifice in the vessel into a reciprocable mould through an extendible chamber shrouding the path of the pouring molten metal and sealing the vessel to the mould, while inert gas is being fed into the extendible chamber, and which includes:
a) causing the molten metal flowing through the vessel outlet orifice to flow through a molten metal static head containing tube of refractory material in the ex-tendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifice and the other end immersed in molten metal in an entry to the mould with a meniscus of molten metal in the entry to the mould and around the tube, and b) supporting to a sufficient extent the static head of molten metal in the vessel and the tube, by means of the pressurized inert gas in the extendible chamber and on the meniscus of molten metal, to maintain the tube filled with molten metal flowing substantially at the same volumetric rate as the casting rate in the mould, the improvement comprising:
c) the outer orifice has a diameter greater than 31.7 mm, and d) the casting rate is controlled substantially by the volumetric rate of extraction of product from the reciprocable mould.
a) causing the molten metal flowing through the vessel outlet orifice to flow through a molten metal static head containing tube of refractory material in the ex-tendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifice and the other end immersed in molten metal in an entry to the mould with a meniscus of molten metal in the entry to the mould and around the tube, and b) supporting to a sufficient extent the static head of molten metal in the vessel and the tube, by means of the pressurized inert gas in the extendible chamber and on the meniscus of molten metal, to maintain the tube filled with molten metal flowing substantially at the same volumetric rate as the casting rate in the mould, the improvement comprising:
c) the outer orifice has a diameter greater than 31.7 mm, and d) the casting rate is controlled substantially by the volumetric rate of extraction of product from the reciprocable mould.
2. In the combination of apparatus for continuous casting aluminum killed steels and alloys, as molten metal, comprising, a vessel for the molten metal, the vessel having CLAIMS CONT.
an outlet orifice for molten metal to flow therethrough from the vessel under a static head, a reciprocable mould for receiving the molten metal when it is flowing through the outlet orifice, an extendible chamber shrouding the path for the flowing molten metal and sealed to the vessel and the mould, and means for feeding pressurized inert gas into the chamber, and wherein there is provided:
a) a molten metal static head containing tube of refractory material in the extendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifice, for receiving the molten metal when it is flowing therethrough, and the other end positioned for immersion in molten metal in an entry to the mould with a meniscus of molten metal therearound in the entry to the mould, and b) means for adjusting the pressure of the inert gas, feed to the extendible chamber for, in operation, sup-porting a static head of molten metal in the vessel by the pressure of the inert gas on the meniscus of molten metal, whereby, in operation, c) the tube is maintained filled with molten metal flowing therein substantially at the same volumetric rate as the casting rate in the mould, the improvement comprising, d) the orifice has a diameter greater than 31.7 mm, whereby e) the casting rate may be controlled substantially by the volumetric rate of extraction of product from the reciprocable mould.
an outlet orifice for molten metal to flow therethrough from the vessel under a static head, a reciprocable mould for receiving the molten metal when it is flowing through the outlet orifice, an extendible chamber shrouding the path for the flowing molten metal and sealed to the vessel and the mould, and means for feeding pressurized inert gas into the chamber, and wherein there is provided:
a) a molten metal static head containing tube of refractory material in the extendible chamber, the tube having one end sealed to a portion of the vessel extending around the orifice, for receiving the molten metal when it is flowing therethrough, and the other end positioned for immersion in molten metal in an entry to the mould with a meniscus of molten metal therearound in the entry to the mould, and b) means for adjusting the pressure of the inert gas, feed to the extendible chamber for, in operation, sup-porting a static head of molten metal in the vessel by the pressure of the inert gas on the meniscus of molten metal, whereby, in operation, c) the tube is maintained filled with molten metal flowing therein substantially at the same volumetric rate as the casting rate in the mould, the improvement comprising, d) the orifice has a diameter greater than 31.7 mm, whereby e) the casting rate may be controlled substantially by the volumetric rate of extraction of product from the reciprocable mould.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA333,604A CA1130983A (en) | 1979-07-18 | 1979-07-18 | Method and apparatus for continuously casting molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA333,604A CA1130983A (en) | 1979-07-18 | 1979-07-18 | Method and apparatus for continuously casting molten metal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1130983A true CA1130983A (en) | 1982-09-07 |
Family
ID=4114910
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA333,604A Expired CA1130983A (en) | 1979-07-18 | 1979-07-18 | Method and apparatus for continuously casting molten metal |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1130983A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2558399A1 (en) * | 1984-01-19 | 1985-07-26 | Poncet Pierre | Improvements to ingot moulds for the continuous casting of metals, and particularly of steel |
| FR2566297A1 (en) * | 1984-06-20 | 1985-12-27 | Metacon Ag | METHOD FOR CASTING A METAL BATH |
| EP0306751A1 (en) * | 1987-09-07 | 1989-03-15 | DANIELI & C. OFFICINE MECCANICHE S.p.A. | Casting method for a continuous casting machine of a reduced height and consequential immersed teeming nozzle |
-
1979
- 1979-07-18 CA CA333,604A patent/CA1130983A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2558399A1 (en) * | 1984-01-19 | 1985-07-26 | Poncet Pierre | Improvements to ingot moulds for the continuous casting of metals, and particularly of steel |
| FR2566297A1 (en) * | 1984-06-20 | 1985-12-27 | Metacon Ag | METHOD FOR CASTING A METAL BATH |
| EP0306751A1 (en) * | 1987-09-07 | 1989-03-15 | DANIELI & C. OFFICINE MECCANICHE S.p.A. | Casting method for a continuous casting machine of a reduced height and consequential immersed teeming nozzle |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3519059A (en) | Method of vacuum slag refining of metal in the course of continuous casting | |
| US4874471A (en) | Device for casting a metal in the pasty phase | |
| RU2147968C1 (en) | Foundry equipment | |
| JPS6178542A (en) | Method and apparatus for controlling conductive liquid stream | |
| EP0686445A1 (en) | Method to control the deformations of the sidewalls of a crystalliser, and continuous-casting crystalliser | |
| CA1130983A (en) | Method and apparatus for continuously casting molten metal | |
| US4306610A (en) | Method of controlling continuous casting rate | |
| US4000771A (en) | Method of and apparatus for continuous casting | |
| CA2198490A1 (en) | Flow control device | |
| US5524704A (en) | Process and device for the continuous casting of very small-diameter wires directly from liquid metal | |
| US5297614A (en) | Process for continuous casting of ultra low carbon aluminum killed steel | |
| CA1182617A (en) | Metal inlet in continuous casters having moving mold walls | |
| US4482003A (en) | Method for continuous casting of steel | |
| US5379828A (en) | Apparatus and method for continuous casting of molten steel | |
| EP1704004B1 (en) | Horizontal continuous casting of metals | |
| KR101267341B1 (en) | Device for preventing breakout of solidified shell in continuous casting process and method therefor | |
| KR101193850B1 (en) | Method for detecting dropping alien substance of submerged entry nozzle and continuous casting method using the same | |
| EP0743115B1 (en) | Method and apparatus for continuous casting of steel materials | |
| KR101185919B1 (en) | Method for warning clogging of submerged entry nozzle | |
| US5494095A (en) | Apparatus for continuous casting of molten steel | |
| CA2023826A1 (en) | Continuous caster mold and continuous casting process | |
| US5232046A (en) | Strand casting apparatus and method | |
| KR101277627B1 (en) | Device for estimating breakout of solidified shell in continuous casting process and method therefor | |
| WO2005042183A1 (en) | A method and a device for detecting slag | |
| GB2029741A (en) | Feed Head for Continuous Casting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |