JPH0341258B2 - - Google Patents

Description

[Detailed description of the invention]

This specification includes ``Strip Casting Apparatus,'' ``Method and Apparatus for Strip Casting,'' and ``Method for Repetitive Marking of Continuously Cast Metal Strip Material,'' all of which are assigned to the applicant. and the subject matter of the co-filed U.S. patent application entitled ``Strip Casting Apparatus'' is incorporated by reference. The present invention relates to casting strip material with fast quench rates and high production rates. More particularly, the present invention relates to an apparatus for rapidly casting thin metal strip material featuring an outwardly diverging nozzle design. The obvious advantages and economic implications of producing thin metal strip materials by casting methods compared to conventional rolling or thickness reduction operations are significant. The fact that strip casting can be performed at such high quench rates to produce amorphous materials is even more significant. However, it is equally true that there are a number of parameters of strip casting that must be controlled or monitored to ensure that the quality of the cast strip is acceptable and that the composition and structure of the strip is uniform. it is obvious. For these reasons, those skilled in the art recognize the difficulties associated with developing commercially viable strip casting equipment. The general concept of casting thin metal materials such as sheets, foils, strips and ribbons was disclosed in the early 1900's. for example,
U.S. Pat. Nos. 905,758 and 993,904 teach a method of manufacturing in which molten metal flows onto a moving cooling surface and the material is drawn onto the surface and hardens into a continuous thin strip. are doing. These references teach that molten metal may be poured onto the smooth outer surface of a rotating, liquid-cooled copper drum or disk to produce strip material. Although the concept was evident early on, there is no evidence that strip casting was commercially successful in the early 20th century. Recently, in U.S. Pat. Nos. 3,522,836 and 3,605,863, methods for producing continuous products, such as metal wires or strips, from molten metal were disclosed. These references teach that molten material in the form of a convex meniscus should be injected from the nozzle. A heat dissipating surface, such as a water-cooled drum, moves in a path substantially parallel to the outlet orifice, contacts the molten metal in the form of a meniscus, and continuously draws material from the meniscus to produce a uniform, continuous product. form. The method detailed above generally works because the heat dissipating surface moving through the molten metal in the form of a meniscus at the nozzle orifice actually affects the rate of flow or drag of the molten metal flowing through the nozzle. This is called the "melt drag method." More recent strip casting developments have focused on relatively narrow improvements in metal strip casting technology. For example, US Pat. No. 4,142,571
The slot structure of a metal strip casting nozzle, which requires particularly strict dimensional accuracy, is described. U.S. Pat. No. 4,077,462 also describes the provision of a specially constructed fixed housing on the outer circumferential surface of a cooling roll used in strip casting. There are many other quenching methods known in the art. Once cooled, melt spinning processes produce metal filaments by cooling an elongated stream of molten metal either in free flight or toward a cooling block. Additionally, melt drawing methods such as crucible drawing disclosed in U.S. Pat. No. 3,838,185 and U.S. Pat. No. 3,896,203
Also known is the pendant drop molten metal drawing method taught in No. However, it has proven difficult to produce uniform sheets or strips by such alternative rapid casting methods.
There are many factors such as casting temperature and pressure, cooling rate of the auxiliary surfaces, surface coating of the casting surfaces, and similar factors that may affect the quality and product thickness of the rapidly cast strip material. Despite the relatively long history of strip casting technology and recent developments in this field, strip casting has not to date been a widely accepted and commercially viable method of operation. various improvements,
Improvements and innovations are required in the field to achieve commercial success in the field of strip casting. In particular, the construction of the tundish for molten metal, the size and dimensions of the nozzle orifice, the spacing from the casting surface, the speed at which such casting surface moves, the quenching rate, the temperature and feed rate of the metal, and the like. More accurate identification and correlation of the proper relationships among the various are required to achieve the uniformity and consistency required for commercially viable production of cast strips. In particular, the construction of certain nozzles and slots and their dimensional relationship to the casting surface on which the strip material is cast can result in uniform strip casting when applied to various casting parameters. was found to be insufficient to produce What is needed, therefore, is a new and improved apparatus for casting relatively wide thin strips of material that overcomes the deficiencies of prior art constructions. Such a desirable device would be reliable, more efficient and effective than structures disclosed in the prior art, and would also provide reproducibility, uniformity and consistency in strip casting. It should be. SUMMARY OF THE INVENTION The present invention, in summary, provides a new and improved apparatus for continuously casting metal strip material. Such a device consists of a nozzle containing a tundish and a slot element. wherein the slot has a substantially uniform cross-sectional dimension over its entire longitudinal dimension. A cool casting surface is arranged on the outside of the nozzle and movable in a direction substantially perpendicular to the longitudinal axis of the slot and past the nozzle. The slot is defined between first and second lips of the nozzle having inner surfaces facing each other at least at the inner portion of the slot. The opposing inner surfaces diverge from each other at the outer portion of the slot. Further, the first and second lips are disposed such that their bottom surfaces face the casting surface with a separation distance of less than 0.120 inches. One of the advantages of the present invention is the provision of a strip casting apparatus that is capable of continuously casting metal strip material having substantially uniform dimensions and substantially uniform quality over its entire length. Another advantage of the present invention is that it provides a strip casting apparatus having an outwardly flared nozzle configuration which is effective in promoting efficient rapid casting of metal strip material. SUMMARY OF THE INVENTION It is an object of the present invention to provide a strip casting apparatus capable of producing repeatable strip casting operations, which produces suitable strips. Another object of the invention is to provide a strip casting apparatus which allows for fairly rapid quenching of the manufactured strip. Rapid cooling here means that an amorphous strip is produced as a result. However, it should be understood that production by continuous casting of crystalline materials is also encompassed by the present invention. A further object of the invention relates to an outwardly diverging nozzle which allows continuous and repeatable rapid casting of metal strip material, in particular of uniform dimensions and uniform quality. Identify and confirm the design and dimensional requirements of the species. These and other objects and advantages will be more fully understood and appreciated by reference to the following detailed description and accompanying drawings. Referring specifically to the drawings, FIG. 1 generally illustrates an apparatus for casting metal strip material 10 of the present invention. This device has strip 1
0 contains the element 12 on which it is cast. In the preferred embodiment, as shown in FIG. 1, a continuous strip 10 is cast onto the smooth outer peripheral surface 14 of a circular rotating drum or wheel. A cross-sectional shape other than circular may also be used.
For example, a smooth truncated cone (not shown here) may be used. Additionally, a belt capable of rotating through a generally oval path may also be used as a casting element. Regardless of the shape used, the casting surface to be cooled should have a width at least as large as that to be cast. In a preferred embodiment, cast element 12 includes:
It consists of a water-cooled precipitation hardened copper alloy wheel containing about 98% copper and about 2% chromium. Copper and copper alloys are selected for their high thermal conductivity and wear resistance, but beryllium copper alloys, steel, brass, aluminum, aluminum alloys or other materials may be used alone or in combination. . For example, a multi-piece wheel with a sleeve of molybdenum or other material may be used. Similarly, cooling may also be done using media other than water. Water is commonly used because it is inexpensive and readily available. In the operation of the strip casting apparatus of the invention,
The surface 14 of the casting wheel 12 must be capable of absorbing the heat generated by contact with molten metal at the initial casting point 16, and such heat is absorbed by most of the copper wheel during each revolution of the wheel. must be conducted. Initially, casting point 16 refers to the location on general casting surface 14 where molten metal 20 exiting tundish 22 first contacts casting surface 14 . Conduction cooling can be achieved by supplying a sufficient amount of water via internal channels located near the outer periphery of the casting wheel 12. Alternatively, the cooling medium may be supplied directly to the underside of the casting surface. Cooling techniques and the like may also be used during strip casting to accelerate or reduce cooling rates and/or to effect expansion or contraction of the wheel. Whether a drum, wheel or belt is used for casting, it should be generally smooth and symmetrical to maximize the uniformity of the strip produced in strip casting. For example, in some strip casting operations, the distance between the outer circumferential casting surface 14 and the surface defining the orifice of the nozzle dispensing molten metal onto the casting surface 14 may not be desirable or established during the casting operation. Do not deviate from the specified distance. This distance is:
It is called separation distance or separation distance. If it is intended to cast a uniform strip of material,
It must be held substantially constant throughout the casting operation. If the casting element is a drum or wheel, the element should be carefully assembled to avoid imperfect circularity during casting to ensure uniformity of the cast strip. Along these lines, approximately 0.5mm (approximately
Drums or wheels that are out of round by 0.020 in.) or more have significant dimensional instability that may be unacceptable for some strip casting operations unless forced or corrected during operation. That's probably the case. Manufacturing the drum or wheel from a single, unitary slab of cold-rolled or forged copper alloy facilitates acceptable dimensional symmetry as well as the elimination of problems associated with weld porosity. I found out that it can be done. However, as mentioned above, other materials constituting the sleeve and coating may be used. The molten material 20 cast in the apparatus detailed herein is preferably held in a crucible 22 or tundish that is provided with an injection orifice 24 or nozzle. Nozzles are not required, but
Generally, it is located below the tundish 22, as shown in FIG. As will be appreciated from the above description, the nozzle 24 may be a separate element of the tundish 22 or the nozzle 24 may be a separate element of the tundish 22.
and the tundish 22 may be of integral construction. In other words, the latter is a structure formed integrally with all or any part of the tundish 22. As shown in FIG. 2, the nozzle 24 located within or forming a lower part of the tundish 22 may consist of a slotted element. Slot 30 is preferably located approximately centrally in nozzle element 24. In this way, slot 3
By locating the 0 approximately in the center, the pressure of the molten metal pushing against them during the casting operation is substantially equalized, thereby helping to ensure uniformity. However, the slot 30 may be located off center if desired. The longitudinal dimension of the slot 30 should approximate the width of the cast strip. However, since there is no restriction as to the longitudinal dimension of the slot, strip casting apparatus having slots of 36 inches (90 cm) or more in length are also within the scope of the present invention. It is highly desirable that the molten metal flow uniformly through the slot 30 of the nozzle 24 of the present invention in order to produce a uniform, high quality strip material. In an alternative embodiment, as opposed to a single slot 30, a plurality of slots 30 having suitable longitudinal dimensions are disposed in longitudinal alignment within the nozzle area of the tundish.
Strips of various widths can be manufactured simultaneously. Regardless of the size of the slot 30 or slots, the cross-sectional dimensions of each slot 30 are substantially uniform throughout their longitudinal dimensions to produce a strip of material having uniform dimensions. It should be. When operating the strip casting apparatus of the present invention, the cooled casting surface 14 is
It moves past the bottom of the slot 30 in a direction substantially perpendicular to the longitudinal axis of the slot. As shown in FIG. 2, slot 30 is defined between first lip 32 and second lip 34 of nozzle 24. As shown in FIG. A first lip 32 is provided at the downstream edge of the slot with respect to the direction of movement of the casting surface 14 as indicated by the arrow in FIG. The second lip portion 34 is
Provided at the upstream edge of the slot. The first lip and the second lip each have inner surfaces 36 and 38 that are opposite and substantially parallel to each other at least in the inner portion of the slot 30. The inner portion refers to the portion of the tundish that is closer to the molten metal holding portion, while the outer portion of the slot 30 refers to the portion that is closer to the casting surface 14. The innermost part of the slot may be provided with a relief angle. For example, as shown in FIGS. 3 and 5, the innermost portions of the first lip 32 and/or the second lip 34 may be cut into a generally V-shape or a more rounded U-shape. , an initial funnel-type structure may be configured for the slot. slot 3
Such a relief angle in the deepest part of 0 maintains a uniform molten metal flow pattern and minimizes flow irregularities and turbulence during strip casting. What is required by the present invention is that, at least in a slightly recessed portion of slot 30, inner surface 3
6 and 38 are opposite and parallel. Beyond these deep parallel and opposing sections, facing the casting surface 14, the inner surfaces diverge into one another in the outer portion of the slot 30. The preferably outwardly flared surfaces are indicated at 40 and 42 in FIG.
This outwardly diverging shape of the inner surface may be achieved in other configurations, such as those shown in FIGS. 3, 4, and 5. In order to satisfy the necessary relationship regarding outward divergence between inner facing surfaces, the third
It should be noted that only one of the inner surfaces needs to flare out, as shown in the Figures and FIG. Similarly, as shown in FIG. 5, a curved surface with an arc of 40 inward or 42 outward may provide such outward divergence. . First and second lips extend from outwardly divergent surfaces 40 and 42 to bottom surfaces 44 and 46, respectively. Such bottom surfaces 44 and 46 of lips 32 and 34 are located opposite casting surface 14 and spaced less than 0.120 inches from the casting surface. In a preferred embodiment, the separation between the bottom surface 44 of the first lip 32 and the casting surface 14 is as short as possible while still allowing the casting surfaces 14 to move beneath them in an unobstructed path. There is. In any case, the first lip portion 32
The distance between the bottom surface 44 and the casting surface 34 is short enough to prevent significant amounts of molten metal from flowing back between them at the nozzle orifice during casting. Casting surface 14 and second lip 3
The distance d between the bottom surfaces 46 and 4 is 2 mm.
(0.080in) is preferred and when some alloys are cast into thin gauge strips.
It may be less than 0.25mm (0.010in). Preferably, at least a portion of the bottom surfaces 44 and 46 are almost completely parallel to the casting surface 14, which is movable below them at least at the nozzle orifice. Drum or wheel and fireproof nozzle 2
4, such parallelism can be achieved by using a sheet of sandpaper or other similar material.
This can be achieved by placing sandpaper in contact with the casting surface 14, with the sand side facing the nozzle 24. Sandpaper is placed between them and the nozzle 24 is moved to align with the casting surface 14.
By making immediate contact and moving the casting surface 14 and the sandpaper past the nozzle 24 simultaneously, the bottom surfaces 44 and 46 are ground with coarse particles so that they are substantially completely parallel to the casting surface 14. Become.
Such parallelism may be achieved even if rounded or other curved casting surfaces 14 are used. To achieve such parallelism in this way for the most refractory nozzles, 400~
I found that 600 grit sandpaper was suitable. The corners between the faces defining the shape of the slot 30 are rounded to minimize the occurrence of turbulence of molten metal during casting. In some instances, sharp corners may be subject to various pressures and flow patterns that can create stress conditions for the nozzle 24 of certain materials, and in some instances may fracture, crack, or It can also become worn and disrupt balanced strip casting conditions. By rounding the corners in this manner, the occurrence of turbulence that may occur when flowing through the nozzle 24 can be minimized. The crucible 22 is preferably constructed from a material that has excellent thermal insulation properties. If the insulation is insufficient to maintain the molten metal at a relatively constant temperature, an auxiliary heater, such as an induction coil, may be used in the crucible 2.
2 and/or around it, or
A resistive element such as a wire would have to be provided. A common material for crucibles is fiberized kaolin, an insulating board made from a naturally occurring, high purity alumina-silica refractory clay. Such insulation materials are commercially available under the trade name "Kaowool HS board". However, for continuous operation or for certain high melting point alloys, graphite, alumina graphite, quartz, clay graphite, boron nitride, silicon nitride,
Various materials may have to be used to construct the nozzle or crucible, including silicon carbide, boron carbide, alumina, zirconia, and various combinations or mixtures of such materials. It will be appreciated that these materials can be reinforced. For example, fiberized kaolin can be strengthened by impregnation with silica gel or the like. It is important that the orifice of nozzle 24 be opened and that its shape remain substantially stable throughout at least one, and preferably multiple, strip casting operations. It is known that the orifice must not become corroded or clogged during strip casting. To obviate this problem, the lips 32 and 34 forming the orifice of the nozzle 24 are designed to maintain dimensional stability and original shape during prolonged exposure to hot molten metal. It may be constructed from a material that is more suitable for Such materials may take the form of a single, generally semicircular element with the slot 30 cut through them, or a pair of inserts may be held in the crucible with the slot 30 inserted between them.
is formed. In a preferred embodiment, the slot or slots in a single element may be ultrasonically machined to precisely manufacture the desired slot dimensions. Such a nozzle 24 is made of quartz,
graphite, clay graphite, boron nitride,
It may be constructed from alumina graphite, silicon carbide, stabilized zirconate silicate, zirconia, magnesium oxide, alumina or other similar melt-resistant materials. Such a nozzle 24 is
It may be held within the orifice of the crucible mechanically using adhesives such as various refractory cements, spring biased mechanisms or the like, and/or using pressure. Drum, wheel or other casting surface 14 of the invention
The drive system and enclosure of the drum should be constructed to be rigid to avoid structural instability and slipping or vibration of the drum as it rotates. In particular, care should be taken not to cause resonance at the operating speed of the casting surface 14.
The casting surface 14 is 61~3050mm (200~10000ft/
min) or above. When utilizing a drum with a circumference of approximately 240 cm (approximately 8 ft), this speed is
Comparable drum speeds of about 25 to about 1250 rpm. The 3 HP variable speed, reversible and dynamically braked motor is approximately 50 mm (approximately 2 inches) thick and 240 cm (approximately 8 inches) thick.
ft) can be a suitable drive system for an alloy casting drum. In some embodiments, the casting surface 14 of the wheel or drum of the apparatus of the present invention is smooth. In certain applications, such as for the production of amorphous materials,
By finishing the outer peripheral surface 14 of the casting drum 12 with 400 grit sandpaper, preferably 600 grit sandpaper, a product with improved uniformity may be created. In the preferred embodiment shown in FIG.
confined within the walls of the slot 30
is made by ultrasonically cutting a clay graphite nozzle 24. First lip 32 of nozzle 24
and the second lip 34 are connected to the slot 3 between them.
Limit 0. In other preferred embodiments of the material of the nozzle 24, plates of quartz or Vycor material or inserts of boron nitride may be used. The desired slot to form the orifice 46 can be precisely cut therein with an ultrasonic drill. As best shown in FIG. 2, the preferred one-piece elements forming the nozzle include:
It may consist of a semicircular ring made of a material that can withstand molten metal. In this embodiment, between 0.25 and 2
A slot having a width of 0.010 to 0.080 in is created by ultrasonically drilling a clay graphite insert, which is then held in crucible 22. Ru. The design of the insert can be modified to help retain the insert forming the nozzle 24 of the crucible 22. A preferred nozzle 24 of the apparatus of the present invention is shown in an enlarged cross-sectional view in FIG. In some embodiments of this device, the dimensions shown in FIG.
It has the following preferred limits:

Table When manufacturing amorphous strips, the slot width f typically ranges from 0.25 to 1.02 mm (0.10 to 0.40 in). When manufacturing crystalline strip materials such as stainless steel, the width of the slot f may be wider, and if thick strips are manufactured uniformly according to the invention, the width of the slot f may be wider.
It will be about mm (0.080in) wide. The primary purpose of tapering the deep portion of slot 30, as shown in FIGS. 3 and 5, is to eliminate clogging of molten metal in the orifice during strip casting. In one example of operation of the apparatus of the present invention, molten metal is placed in a heated crucible 22. A heater, such as an induction coil of resistant wire, may be provided in and on the crucible 22 to maintain the molten metal at a relatively constant temperature as desired. Alternatively, the molten metal may be poured directly into a preheated crucible. The preheat temperature should prevent freezing or clogging of the slot 30 during the initial casting operation, and the temperature of the flowing metal should be such that the temperature of the flowing metal should be such that the molten metal is then kept in the crucible 2.
2 and nozzle 24 should be maintained at a sufficient temperature to ensure uninterrupted flow. In some applications, the nozzle itself may be heated externally throughout the casting operation. Additionally, the metal fed to the crucible 22 may be superheated so that any temperature drop will not adversely affect the metal flowing through the nozzle 24. Additionally, the height of the static pressure head of the metal in the tundish 22 is preferably maintained at a relatively constant level, and typically a relatively constant static head pressure is maintained at the nozzle throughout the casting operation. is maintained less than 250 mm (10 in) above the nozzle 24 so that the This may be done by first pouring molten metal into the crucible to the desired height and then additional molten metal being poured into the crucible to maintain a constant static head of metal. The rate at which additional molten metal is supplied to the crucible should substantially match the rate at which the metal flows down from the nozzle orifice onto the casting surface 14. By maintaining a relatively constant height in the crucible, the flow pressure of the molten metal flowing through the orifice is maintained relatively constant so as not to adversely affect the casting operation or the quality of the strip material. be done. Alternatively, externally applied pressure may be used to control the nozzle pressure. The nozzle 24 of the present invention is characterized by lip surfaces 40 and 42 that flare outwardly in the outer portion of the slot. Such a structure promotes the flow of an increased amount of molten metal onto the moving casting surface 14, thereby improving the lateral flow of molten metal onto the casting surface 14 and producing high quality strip material. Form 10. In a preferred embodiment, the width b of the orifice of slot 30 at its outermost flared portion is 5.
The width may be as wide as mm (0.200in). This dimension is more than four times the width f of the slot 30 measured between the rear parallel opposing surfaces. Such a construction provides a relatively large casting cavity in the outer portion of the nozzle even though the molten metal is fed through a relatively narrow internal orifice. During strip casting, this movement of the molten metal laterally inside the cavity improves the uniformity with which the metal is delivered to the casting surface 14, so that the metal is cast on the casting surface 14. Improve the quality of strip 10. Additionally, as discussed above, the presence of such a cavity reduces the tendency for the narrow orifice to freeze and block the nozzle because it is located further from the cooled casting surface 14. A variety of alloys, including certain braze alloys, nickel-based braze alloys, stainless steels, and certain silicon steel varieties, have been cast with success using the apparatus of the present invention. In some applications, the cast alloy has been shown to be amorphous, and in other applications, the cast strip material has been shown to be crystalline. During casting of the strip material, a tendency was observed for the strip 10 to extend beyond the nozzle and onto the casting surface 14 over a considerable distance, several feet or more. It is conceivable that if the strip material is held on the rotating casting drum or wheel 12 for one revolution, damage to the crucible 22, and in particular to the nozzle orifice, may occur. This can easily be done by using an air wiper or a doctor blade, such as a knife-type element that rests on or near the drum surface 14, for about 2.5 to 6 feet or more from the orifice. It was found that it was possible to eliminate such adhesion. Using such an arrangement, the cast strip can be removed from the drum by such a doctor blade. The use of such a doctor blade allows the casting surface 1 to be removed from the crystalline strip material.
It has been found to be particularly useful in the production of thinner amorphous strip materials, which appear to have a greater tendency to adhere to 4. The force that keeps the strip on the casting surface is
This may be thought to reflect the nature of the thermal contact between the strip and the casting surface. For purposes of the present invention, the casting of relatively high quality strip material consisting of amorphous material containing at least 25% amorphous material is feasible using the apparatus and method detailed above. Yes, and practical. The quenching rate when producing amorphous materials must be faster compared to the rate when producing crystalline materials. The rate of quenching may be facilitated, such as by increasing the speed of the casting surface or the like. Although preferred embodiments have been detailed above for purposes of illustration, it will be apparent to those skilled in the art that modifications to the numbers set forth therein may be made without departing from the scope of the invention. .

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view illustrating a representative apparatus of the present invention used to continuously cast strip material. FIG. 2 is a cross-sectional view of an outwardly flared nozzle that is part of the stripping apparatus of the present invention. 3, 4 and 5 are cross-sectional views of a selectively outwardly flared nozzle that is part of the strip casting apparatus of the present invention. 10: Strip, 12: Drum, 14: Casting surface (outer surface, 16: First casting point, 20: Molten metal, 22: Tundish (crucible), 24:
Nozzle (orifice), 30: Slot, 32:
First lip, 34: Second lip, 36: Inner surface of first lip, 38: Inner surface of second lip, 4
4, 46: Bottom surface.

Claims (1)

Claims: 1. a tundish for receiving and retaining molten metal; a nozzle comprising a slotted element disposed within the tundish, the longitudinal dimension of the slot approximating the width of the strip to be cast;
the slot has a cross-sectional dimension that is substantially uniform throughout the longitudinal dimension of the nozzle; the slot has a width at least as wide as the width of the cast strip and is located on the outside of the nozzle; a continuous metal strip casting apparatus comprising: a cooling casting surface movable past the nozzle in a direction substantially perpendicular to the longitudinal axis of the slot; and a second lip, and has a deep part near the tundish and an outer part near the casting surface, and the first lip and the second lip are in the deep part of the slot. and substantially planar inner surfaces facing each other at the slot, said inner surfaces being mutually parallel at least at the innermost portion of the slot and mutually divergent at the outermost portion of the slot; The width of the diverging portion of the slot is more than four times the width of the slot measured between parallel and opposing surfaces at the back: and the first lip and the second lip are 3.1 mm.
a bottom surface facing the casting surface at a distance of less than (0.120 inches) apart; the bottom surface of the first lip has a length at least twice the width of the inner portion of the slot; The continuous metal strip casting apparatus. 2. The device of claim 1, wherein the spacing between the opposing parallel inner surfaces of the first and second lips is between 0.25 and 1.02 mm (0.010 and 0.040 inches). 3. The spacing between the inner surfaces of the first and second lips outwardly of the slot is at least 0.25 mm (0.010 in.) greater than the spacing between the opposing parallel inner surfaces of the first and second lips. ) or more. 4. The spacing between the inner surfaces of the first and second lips in the outwardly flared portion of the slot is between 1.02 and 4.6 mm (0.04 and 0.18 inches). Apparatus described in section. 5. The spacing between the inner surfaces of the first and second lips in the outwardly flared portion of the slot is 2.5 to 3.8 mm (0.10 to 0.15 inches), as claimed in claim 1. The device described. 6 Casting surface is 61~3050m/min (200~10000m/min)
2. The device of claim 1, wherein the device is movable past the nozzle at a surface linear velocity of ft/min. 7 Casting surface is 550~1220m/min (1800~4000m/min
2. The device of claim 1, wherein the device is movable past the nozzle at a surface linear velocity of ft/min. 8 The casting surface consists of the outer peripheral surface of the water-cooled wheel.
An apparatus according to claim 1. 9. The apparatus of claim 8, wherein the wheel is made of a metal selected from the group consisting of copper, copper alloys, aluminum, aluminum alloys, steel, molybdenum, and combinations thereof. 10 The nozzle is made of graphite, aluminagraphite, clay graphite, quartz, fiberized kaolin, boron nitride, silicon nitride, silicon carbide, boron carbide, alumina, zirconia, stabilized zirconate silicate, magnesium oxide and combinations thereof. 2. The device of claim 1, wherein the device is constructed of a material selected from the group consisting of: 11. The device of claim 1, wherein at least a portion of the bottom surfaces of the first and second lips are completely parallel to the casting surface below.