JP2008531285A - Method for continuous casting of molten metal and molten metal feeder - Google Patents

Abstract

The present invention provides a feeder that supplies molten metal to a mold formed between opposing casting surfaces of a continuous caster. The feeder is a protruding lower end having an inner surface that contacts the molten metal, a generally flat outer surface, and an end surface at the outer end of the protruding tip that extends between the inner surface and the outer surface. A protruding nozzle tip including at least a wall is included. The inner surface is generally flat, preferably with an inclination of no more than 8 °, inclined in the direction of the outer surface which is considered to move towards the tip end. The end surface is generally flat and extends from the inner surface to the outer surface at an acute angle less than 88 °, such as 15-80 °, for a direction away from the tip end of the inner surface. The feeder casts a metal plate article with reduced surface defects caused by metal oxide fracture during casting.

Description

  The present invention relates to continuous casting of molten metal, preferably in aluminum and aluminum alloys. In particular, the present invention relates to a method for introducing molten metal into a casting cavity of a continuous caster and the design of a metal feeder used for this purpose.

  For example, continuous casting of metal has been performed for many years using, for example, a twin belt casting machine, a twin roll casting machine or a rotating block caster. These types of continuous casters typically have a horizontal or slightly downwardly cast cavity formed between two opposing continuously rotating casting surfaces. When molten metal is introduced into one end of the casting cavity and drawn into the casting cavity by the rotating casting surface, the molten metal is cooled and solidified. A solid metal ingot, slab or strip then emerges from the opposite end of the casting cavity.

  Molten metal is introduced into the casting cavity by some form of molten metal feeder that introduces a flow of molten metal between the casting surfaces. The feeder may be in the form of an open-topped trough and the molten metal is directed to the casting cavity by means of an open spout or runner (hereinafter “pool feeding”). Or, more preferably, a nozzle is used that surrounds and limits the molten metal until it appears from the end.

  Post-cast ingots produced on DC (direct chill) and continuous strip casters produce metal slabs or strips with various types of surface defects. In DC casting, such defects are often removed by scalping. However, in continuous strip casting, sculpting may not be practical or economical and it is desirable to provide an article with minimal surface defects from the outset.

  Surface defects can be caused by a number of mechanisms, including reaction with refractory materials of the system supplying the metal, and non-uniform local cooling. Many improvements have been made to reduce the size and number of surface defects.

  Another common mechanism involves the inclusion of surface oxides that form a cold shut (or entrainment). Such defects are caused by inevitable surface oxides that form on the meniscus surface of the molten metal that exits the metal feeder and contacts the moving casting surface. As it drags along the moving casting surface, the oxide film is pulled and cracked, resulting in relatively large, visible irregular surface defects. This surface defect not only affects the appearance of the cast article, but can also cause structural weaknesses that cause rollability problems. These defects are particularly serious for critical applications of surfaces such as foils, cans and automotive boards and can limit the speed of casting.

  For example, as shown in US Pat. No. 5,636,681 (issued June 10, 1997) and US Pat. No. 6,725,904 (April 27, 2004), the structure of the feeder and continuous casting. There are many known references that disclose how to introduce metal into the cavity. These patent publications disclose feeder designs intended to produce a turbulent metal flow into the casting cavity.

  European Patent No. 0 902 271 of Hazelett-Stripe-Casting Corporation (inventor Valerie G. Kagan), entitled December 17, 2003, “pours” metal into a belt. ”Discloses a belt-type casting apparatus with a metal delivery device. The tip of the supply device is arranged away from the belt and terminates at the end surface located perpendicular to the inner surface of the supply device that contacts the metal.

  U.S. Pat. No. 4,648,438 issued on March 10, 1987 to Hazelett-Stripe-Casting Corporation (inventor Robert W. Hazelett et al.) Describes a belt-type casting machine and a tip end "squared" ”Discloses a metal supply device arranged at right angles to the casting surface.

  The following is an example of a strip casting machine whose interior has a tip that tapers forward.

  U.S. Pat. No. 3,774,670 issued on Nov. 27, 1973 to Prolizenz AG (inventor Ivan Gyongoyos), Hunter Engineering Co. issued on Aug. 26, 1997. , Inc. (Inventor Denis M. Smith) US Pat. No. 5,660,757 and Aluminum Company of America (Inventor Nai-Yi-Li et al.) US Pat. No. 6,173,755 issued Jan. 16, 2001.

  The object of the present invention is to improve the continuous casting of molten metals, in particular molten aluminum and molten aluminum alloys, in particular by reducing the surface defects of cast articles and more particularly by reducing the inclusion of oxides on the cast surface. is there.

  In one aspect of the present invention, a feeder is provided for supplying molten metal to a mold formed between opposing casting surfaces of a continuous caster. The feeder has a protruding tip, an inner surface that contacts the molten metal, an outer surface, and an end surface at the outer extremity of the protruding tip that extends between the inner and outer surfaces. A nozzle having a protruding tip including at least one wall. The inner surface and the end surface are connected by a linear portion (or a straight line, line) to form an included angle smaller than 88 °, and the nozzle wall is 0.5 to It has a thickness of 3 mm.

  In another embodiment of the present invention, a set of endless casting surfaces facing each other through a central main cavity, means for moving the set of casting surfaces in the same direction at the same speed, and from one end of the casting cavity to the casting cavity. A continuous casting machine including a feeder for introducing a molten metal is provided. The feeder is a protruding tip, at least one wall comprising an inner surface in contact with the molten metal, an outer surface, and an end surface at the outer end of the protruding tip that extends between the inner surface and the outer surface. A nozzle having a protruding tip including The inner surface and the end surface are connected to each other at a linear portion to form a included angle smaller than 88 °. The wall of the nozzle has a thickness of 0.5 to 3 mm at the adjacent portion of the linear portion, and the linear portion is held at a distance of 0.5 to 3 mm from the adjacent casting surface during casting.

  In yet another embodiment of the present invention, a method is provided for continuously casting molten metal to form a cast metal strip article. The method includes feeding a molten metal that forms an oxide layer upon contact with air from a nozzle having a protruding nozzle tip to at least one moving casting surface such that the molten metal is A meniscus having a metal oxide surface coating is formed between the tip end and the casting surface. Molten metal is supplied from a tip portion having a wall having an inner surface and an end surface that are connected to each other at linear portions and form an included angle of less than 88 °. The wall has a thickness of 0.5 to 3 mm at a portion adjacent to the linear portion. The tip portion is arranged so that the linear portion is separated from the adjacent casting surface in the range of 0.5 to 3 mm during casting.

  The present invention relates to obtaining a continuously cast strip article having excellent surface quality. The inventors have noticed the presence of periodic surface striations that extend across the cast article at right angles to the casting direction by improving the surface quality by making normal improvements in casting technology and equipment. It was. The inventors have found that these streaks are due at least in part to the vibration of the meniscus formed between the casting tip and the casting surface. When a reactive metal such as aluminum is cast, the meniscus is covered with a metal oxide layer, and the metal oxide layer can be broken by vibration of the meniscus. The underlying exposed metal then rapidly grows a new oxide layer by reaction with air, but this breakdown is visible on the surface of the cast product because the oxide layer is pulled on the casting surface. Forming defects. It has been theorized that meniscus vibration is inherent to continuous casters, at least belt casters used to cast aluminum and aluminum alloys or other reactive metals, and cannot be completely eliminated. Accordingly, the inventors have found that another approach, viz., Because of its regular and good appearance, is to vibrate to form a cast article with small, regularly spaced streaks that do not clearly appear as surface defects. The uniformity was improved. In particular, we have found that a meniscus vibration of at least 50 Hz, for example 50-200 Hz, is necessary to obtain an acceptable appearance.

  The meniscus tends to vibrate at right angles to its surface. That is, in the region that becomes more round and extends from the nozzle to the casting surface, it tends to become less round for each such cycle represented by one vibration.

  The inventors have determined that the frequency of meniscus vibration is affected by various parameters such as the application of external forces such as air pressure in a small gap between the nozzle and the casting belt and the application of a varying magnetic field to the meniscus region. Found that could be. However, the inventors have found that the most effective way to increase the meniscus frequency is by design improvement and the placement of nozzles used to inject molten metal onto the casting surface.

  For casting nozzle designs, conventional nozzles use a set of protruding walls that define a channel of molten metal between the inner surfaces that the opposing metal contacts. The flow path has an outlet at the tip of the nozzle where a wall protruding at a flat end surface extending at right angles to the inner surface with which the metal comes into contact terminates. The wall also has an outer surface with a small gap and extending parallel to the casting surface. With this type of nozzle, not only was the meniscus vibration slow and unstable, but the vibration caused the metal to contact the end face of the nozzle wall, forming oxide whiskers (or whiskers) and It has been found that this leads to an increase, which causes further adhesion and vibration interference. The inventors have found that this effect can be minimized or eliminated by "cutting-backing" the end face at an angle of several degrees or more. This results in an inclination in the rearward direction from the linear portion in contact with the inner surface in contact with the metal, less than 88 °, more preferably less than 85 °, even more preferably less than 80 degrees, most preferably 75. It means that an included angle (an angle within the material of the nozzle wall) can be formed smaller than °. Smaller angles are so far impractical for manufacturing nozzles (although the desired effect is clear if manufacturing limitations are overcome). A more desirable lower cutback angle limit is 30 °. A more preferred lower angle is 45 °. Most preferably, the end face of the nozzle wall is flat over its entire length, ie flat across the nozzle from the intersection of the inner and outer walls, from side to side. This is advantageous for forming streaks more regularly, especially across the width of the casting cavity.

  The above-mentioned linear part (the apex of the included angle) is the so-called “take off point” of meniscus (ie, a little before the contact between the molten metal and the nozzle disappears and the casting surface comes into contact). The point supported by the surface tension is formed. It is indispensable to have such a linear portion (that is, a sudden change in the direction in which the planes usually contact each other at an acute angle). Unless there is a restriction on the theory of operation of the present invention, the linear portion and acute angle of this position determine the position where the metal emerges from the tip, so that the metal does not escape on the end face of the nozzle wall. Is clear. The vibration of the metal is instead localized to the take-off line, where the vibration breaks the oxide layer regularly and periodically as the metal flows, resulting in a regular fine line in the final product.

  Also, if there is no theoretical limitation, the meniscus vibration amplitude appears to increase with casting speed (ie, the speed of the casting belt). The greater amplitude of vibration increases the risk that the meniscus will “wander” to the nozzle end face. Thus, the “cut back” angle may desirably be decreased as the casting speed increases (ie, the angle of the end face relative to the inner surface is desirably smaller, eg, 15 ° -80 °. Should.). In high speed casting, the angle should preferably be 75 ° or less, with 70 ° or even 65 ° being a more preferred upper limit.

  Ideally, for at least aluminum and aluminum alloys, the meniscus should vibrate at a frequency between 50 Hz and 200 Hz. The frequency range depends on the physical properties of the metal, such as density, viscosity and surface tension, but only if these physical properties change significantly. There is very little change between aluminum alloys, but when the base metal changes (eg from aluminum to copper), significant changes occur that significantly affect vibration.

  In the present invention, the distance between the “take-off point” and the casting surface should be clearly limited. If this distance is too large, the meniscus will be deflected to the end face wall of the tip and metal may flow in the opposite direction under the nozzle, making it difficult or impossible to hold the meniscus stably. This flow characteristic seems to cause more liquid to be poured rather than faster casting. However, the spacing must be large enough so that a meniscus can be formed between the take-off point and the casting surface. The minimum distance is controlled by the restriction placed on the tip, depending on the construction method and the need for the tip to be slightly spaced from the casting surface. A preferred spacing (from take-off line to casting surface) is about 1 mm ± 0.5 mm. However, the present invention is also effective for nozzle wall thicknesses (typically about 1 mm or 1/32 inch) and spacings of about 3 mm or less.

  Molten metal can be supplied from a conventional head box or tundish to a closed or closed nozzle (or open topped nozzle). The present invention may use both types of nozzles, but a closed nozzle is preferred.

  If the nozzle is sealed, the two walls forming the nozzle may be flat and parallel over the entire length, or the ends may be “flared” or “divergent”. That is, the wall adjacent to the terminal side supplying the molten metal is inclined outward at an angle of usually 8 ° or less. This allows the wall to converge toward the casting surface with a small angle at the end of the tip.

  The present invention provides both horizontal continuous casting and vertical continuous casting, ie twin belt casters, rotary block casters, and even twin-roll casters (a twin roll caster is preferably When using the present invention, it is operated at high speed).

  As mentioned above, continuous casting of metal to form strip articles (often referred to as sheets, plates, slabs, ingots, billets, layers, etc.) has been a number of different over the years. It is done with different types of continuous casting machines. For example, a twin belt casting machine is disclosed in detail in U.S. Pat. No. 4,061,177 issued to Alcan Research and Development Limited (inventor Olivo Giuseppe Civilotti), issued Dec. 6, 1997, of this type ( Casters are suitable for practicing the present invention (as well as other types). This patent disclosure is incorporated herein by reference, and a brief and simple description is given below.

  The illustrated twin belt caster 10 has upper and lower endless rotating metal belts 12 and 14, and the closely spaced, opposed endless rotating metal belt casting surfaces 16, 18 are cavities defined by the endless rotating belt. Through the casting cavity (casting mold) 20 from the inlet 21 to the cavity outlet 22, they are arranged essentially parallel to each other. The endless rotating metal belt is guided because it rotates via a suitable ellipse or other looped return between the casting cavity inlet and outlet. The upper belt 12 passes around a cylindrical drive roll 24 and, if necessary, an upper path that may be further supported by a row of idler rollers or the like, and a semi-cylindrical bearing 25. . The lower belt is essentially the same, but is a mirror image path that includes a drive roll 26 and a semi-cylindrical bearing 27 similar to the semi-cylindrical bearing located directly above. . A feeder 30 (not shown in FIG. 1 but shown in FIG. 2) including a nozzle 32 having a protruding tip 34 with a molten metal outlet 35 at the outer end (end) 36 allows the molten metal to be Introduced into the casting cavity. Accordingly, the molten metal enters the casting machine from the feeder 30 in the direction indicated by the arrow A (FIG. 1), and the molten metal is solidified in the casting cavity 20 and cast at the outlet of the casting cavity in the direction indicated by the arrow B. Cast strip articles emerge from the machine. The opposite (inner) surfaces 17, 19 of the casting belt are typically cooled using a cooling water jet, for example as shown at 23.

  FIG. 2 is an enlarged view of the end of the casting machine adjacent to the inlet 21 of the casting cavity 20. The belts 12 and 14 are indicated by alternate long and short dash lines. As noted above, for example, a type as disclosed in US Pat. No. 5,636,681, issued Jun. 10, 1997, to Alcan International Limited, incorporated herein by reference. A metal feeder 30 is provided. The feeder 30 has top and bottom nozzle mounts 38 that hold the metal supply nozzle 32 in place so that the tip 34 of the metal supply nozzle 32 protrudes between the two movable belts 12 and 14 of the belt caster. including. Mount 38 is bolted to the caster structure (not shown) and upstream opening 40 coincides with a similar opening in a tundish or feed box (not shown) used to supply molten metal to the caster. The nozzle 32 is supported so that it can. A resilient refractory seal (not shown) is used between the upstream side 41 of the nozzle and the tundish or feed box. The nozzle 32 is made of a refractory material as shown, for example, in US Pat. No. 5,636,681, and the tip 34 has a slightly deviated shape as shown. A spacer 46 in the form of a wire mesh or metal strip is provided between the outer surface of the nozzle and the adjacent portion of the cast belt to maintain a predetermined controlled spacing between the nozzle and the belt. The nozzle includes a refractory wall 53 having an inner surface 55 that contacts molten metal facing each other through a molten metal conveyance channel that leads from the opening on the upstream side to the molten metal outlet 35. The wall has an end face 56 that connects to the inner surface 55 at a linear portion 65. This wall also has an outer surface 54 facing the casting belts 12 and 14.

  The present invention relates primarily to the supply of molten metal into the casting cavity in the nozzle tip 34 region. This will be described in more detail with reference to FIGS.

  FIG. 3 shows a conventional nozzle tip 34. Only the lower wall 53 of the nozzle tip adjacent to the lower casting belt 14 is shown. The upper wall of the nozzle tip and the upper casting belt can be recognized as a mirror image of this lower part. The tip shown is normally disposed at an right angle (as shown by the small rectangle) to the outer surface 54 that extends parallel to the surface of the adjacent casting belt 14, the inner surface 55 that contacts the molten metal, and the inner surface 55. And a narrow end face 56. In molten metal supply and casting, a meniscus 58 (ie, an unsupported metal surface) bridges the gap between the nozzle tip 34 and the adjacent cast belt 14. For reactive metals such as aluminum and aluminum alloys (ie, metals that spontaneously form oxides upon contact with air), the meniscus is covered by an oxide layer 60. As the belt 14 moves through the casting cavity, the oxide layer 60 is pulled along the belt by friction and is stressed in the meniscus region. It is found that at the meniscus, the oxide layer tears periodically and the exposed metal immediately forms a new oxide layer. The resulting breakdown and regrowth of the oxide film results in surface defects in the cast article. The inventors of the present invention have found that the effect of unavoidable oxide breakdown on the surface quality can be reduced or eliminated by breaking the oxide film frequently and in a controlled manner rather than irregularly. .

  In particular, the inventors have found that free oscillate of the meniscus at a controllable frequency of at least 50 Hz controls and reduces the effects of oxide layer breakdown. For example, the nozzle tip designed and used in accordance with the present invention, as shown in FIG. 4, has been found to allow such regular vibration and oxide breakdown to occur. At this tip, the angle α between the inner surface 55 and the end surface 56 (hereinafter referred to as “cut back angle” and also referred to as “included angle”) is less than 88 °. It is an acute angle, preferably 15 ° to 85 °, more preferably 15 ° to 80 °, still more preferably 30 ° to 80 °, and still more preferably 30 ° to 75 °. When such an angle is used, the meniscus 58 can vibrate freely and is not subject to any external influence, the physical characteristics of the molten metal, the substrate (casting belt) moving with the molten metal and the distance between the tip and the belt. It has a “natural” frequency determined by (interval “S” shown in FIG. 4). The use of the acute cutback angle α in combination with the accurately defined tip-to-belt spacing S is a linear shape where the casting surface 61 of the casting belt 12 intersects the inner surface 55 and the end surface 56 of the nozzle tip. This means that the shape of the meniscus between the portions 65 (hereinafter referred to as “take-off point” or “take-off line”) is reliably controlled, The frequency of vibration is stable. The use of an acute cutback angle ensures that the final point of contact between the molten metal and the nozzle is constrained to a predetermined position at the tip, ie, a crossed line (or line of intersection) 65. To. In this respect, the surface of the molten metal changes from a supported state (supported by a nozzle) to an unsupported state (meniscus form), and the oxide film on the surface of the molten metal vibrates the meniscus. Will be repeatedly destroyed along. Oxide breakdown has a constant frequency that is the same as the frequency of vibration, causing small and regular cracks, thus producing regular and minimal defects on the metal surface.

  When the cutback angle is not an acute angle (for example, 90 ° as in a normal nozzle), the meniscus 58 may come into contact with the end face 56 of the tip during vibration. This contact immediately forms an oxide whisker on the end face of the tip, resulting in adhesion to the end face 56 below the crossed linear portion 65 of the meniscus. This adhesion is variable and prevents constant free oscillation of the meniscus. Therefore, the cracking of the oxide layer is irregular and delayed, resulting in increased surface defects.

  The amplitude of meniscus vibration appears to be related to casting speed. That is, larger amplitudes are observed at higher casting speeds. Larger amplitudes make it more difficult for the meniscus to stabilize at the nozzle, so it is desirable to lower the angle α at higher casting speeds, and an angle of 75 ° or less is typically desirable at higher casting speeds. On the other hand, when the cutback angle is less than 15 °, it is difficult to manufacture a nozzle tip having necessary rigidity and strength characteristics.

  The distance S (the distance between the “take-off point” 65 at the point where the meniscus contacts the casting surface 61 and the casting surface 61 of the casting belt) affects the characteristics of the casting process. In most alloy and casting practices, the spacing S should be in the range of 0.5 mm to 3.0 mm. The distance S includes the thickness at the tip of the lower wall 53, and therefore this thickness also needs to be in the range of 0.5 mm to 3.0 mm. The most preferable distance S is 1 mm ± 0.5 mm. This distance can be achieved, for example, by making the side wall 53 with a 1 mm thickness tip slightly compressed with a rigidizer by means of an alumina-silicate fiberboard (eg “Fiberfrax®”). is there. This material is slightly compressed and has a slight thickness change during use due to thermal expansion, so that there is a slight gap between the side wall 53 and the casting surface to maintain a spacing S of about 1 mm. Is possible. Despite its thinness, the above materials have sufficient strength and rigidity and also have a relatively low desirable thermal conductivity.

  The invention is illustrated in more detail by reference to the following examples, which are not intended to limit the scope of the invention.

  Different feeder tips on a single mold surface (water cooled) using a top open box with a sliding bottom to simulate the state of metal flow from a fixed feeder tip to a moving water cooling belt The effect of angle was investigated. The apparatus used is schematically shown in FIG. 5 (plan view) and FIG. 6 (vertical longitudinal sectional view).

  Molten metal is poured into the box 70, and the bottom plate 71 is pulled horizontally at a predetermined speed and a predetermined molten metal temperature, and the end 72 of the moving bottom plate on the iron plate mold 73 where the molten metal gradually solidifies towards the moving bottom plate. Molten metal 75 was flowed from. The moving bottom plate (forming a thin slide) is made of the same material as the tip of the feeder used for continuous casting, and the shape of the right end is changed as shown in FIGS. The effects on solidified metal were investigated, such as meniscus break line and other ingot surface defects. The speed at which the bottom plate was drawn was varied to simulate different metal flow rates and conditions from the tip to the mold surface. The shape of FIG. 7A corresponds to the present invention with a cut back angle of 75 °. FIG. 7B has a cutback angle of 120 °, ie, outside the scope of the present invention. FIG. 7C has a compound surface, but the inner corner (“take-off point”) is 120 °. Since the take-off point is not formed, the second angle does not affect the meniscus. FIG. 7D has a curved outer surface so that there is no clear inner corner or “take-off point”. 7B, 7C and 7D all produced undesirable oxide cracking at the solidification junction, but the condition of FIG. 7A, the tip undercut angle was 75 °. The angle showed good results. The relief angles 60 ° and 30 ° obtained with the same design of FIG. 7A with a sharp upper edge all showed good results.

  A series of castings were performed on a pilot scale casting machine using metal feed nozzles with various cutback angles. Casting was performed on a copper belt by casting a 10 mm thick aluminum alloy AA5754 at a speed of 8 to 10 m / min. The surface of the cast strip was observed and photographed. The results are shown in FIGS. 8 to 12 and summarized in Table 1 below.

  Cutback angles of 93 ° and 88 ° are outside the range of the present invention, and cast plates with such angled tips showed unacceptable folds or banding. . A spacing of 30 mm, a typical value for such a band, corresponds to about 4-6 Hz. Cutback angles less than 88 ° are free of such noticeable streaks, but exhibit a finer, more regular surface pattern with a spacing of about 1 mm corresponding to a frequency greater than 100 Hz.

1 is a partial side cross-sectional view of a twin belt casting machine of the type capable of implementing the present invention (without a molten metal feeder). 1 is a cross-sectional view of a molten metal supply apparatus and adjacent portions of a twin belt caster of the type that can implement the present invention. FIG. 2 is a cross-sectional view of a portion of a conventional nozzle and adjacent casting belt and molten metal flow, showing the formation of a molten metal meniscus FIG. 4 is a view similar to FIG. 3 except that a portion of the nozzle according to the present invention is shown. It is a top view of the test apparatus shown in an Example. It is sectional drawing of the test apparatus shown in FIG. It is a figure which shows the cross section of the front part used in Example 1. FIG. It is a figure which shows the cross section of the front part used in Example 1. FIG. It is a figure which shows the cross section of the front part used in Example 1. FIG. It is a figure which shows the cross section of the front part used in Example 1. FIG. FIG. 6 shows a surface macrophotograph of an aluminum alloy strip casting using a conventional nozzle with an angle between the inner surface and the end surface of 93 °. FIG. The surface macro photograph of the aluminum alloy strip cast product using the nozzle concerning this invention whose angle between an inner surface and an end surface is 88 degrees is shown. 3 shows a surface macro photograph of an aluminum alloy strip cast product using a nozzle according to the present invention in which an angle between an inner surface and an end surface is 78 °. The surface macro photograph of the aluminum alloy strip castings using the nozzle concerning the present invention whose angle between an inner surface and an end surface is 48 degrees is shown. The surface macro photograph of the aluminum alloy strip castings using the nozzle concerning this invention whose angle between an inner surface and an end surface is 33 degrees is shown.

Claims (20)

A feeder for supplying molten metal to a mold formed between opposing casting surfaces of a continuous casting machine, the feeder comprising:
A protruding tip comprising at least one wall comprising an inner surface with which the molten metal contacts, an outer surface, and an end surface at the outer end of the protruding tip that extends between the inner surface and the outer surface. Including a nozzle having an open tip,
The inner surface and the end surface are connected by a linear portion to form a included angle smaller than 88 °, and the at least one wall has a thickness of 0.5 to 3 mm at a portion adjacent to the linear portion. A feeder characterized by   The feeder according to claim 1, wherein the included angle is 15 ° to 85 °.   The feeder according to claim 1, wherein the included angle is 15 ° to 80 °. The feeder according to claim 3, wherein the included angle is 15 ° to 75 °.   The feeder according to claim 3, wherein the included angle is selected from a range of 30 ° to 70 °.   The feeder according to claim 1, wherein the thickness is 1 mm ± 0.5 mm.   4. A feeder as claimed in claim 3, wherein the tip has two walls aligned with each other with inner surfaces in contact with the metal facing each other via a channel carrying the metal.   The feeder according to claim 7, wherein the walls of the tip end portions deviate from each other in a direction extending toward the outer terminal.   9. The feeder of claim 8, wherein the wall deviates at an angle of about 8 degrees from the longitudinal axis of the tip. A set of endless casting surfaces facing each other through a casting cavity;
Means for moving the casting surface in the same direction at the same speed;
A feeder for introducing molten metal into the casting cavity at one end of the casting cavity;
A continuous casting machine including
The feeder has at least one protruding tip, comprising an inner surface in contact with the molten metal, an outer surface, and an end surface at the outer end of the protruding tip that extends between the inner surface and the outer surface. Including a nozzle having a protruding tip including two walls;
The inner surface and the front end surface are connected by a linear portion to form a included angle smaller than 88 °, and the at least one wall has a thickness of 0.5 to 3 mm at a portion adjacent to the linear portion. The continuous casting machine is characterized in that the linear portion is held at a distance of 0.5 to 3 mm from one adjacent casting surface during casting.   The continuous casting machine according to claim 10, wherein the included angle is 15 ° to 85 °.   The continuous casting machine according to claim 10, wherein the included angle is 15 ° to 80 °.   The continuous casting machine according to claim 12, wherein the included angle is 15 ° to 75 °.   The continuous casting machine according to claim 12, wherein the included angle is 30 ° to 70 °.   The continuous casting machine according to claim 10, wherein the interval is 1 mm ± 0.5 mm.   13. The continuous casting machine according to claim 12, wherein the tip has two walls aligned with each other with inner surfaces in contact with the metal facing each other through a channel carrying the metal.   The continuous casting machine according to claim 16, wherein the walls of the tip end portions deviate from each other in a direction extending toward the outer terminal. The continuous caster of claim 17, wherein the wall deviates at an angle of about 8 ° from the longitudinal axis of the tip. A method of continuous strip casting of molten metal to produce a cast metal strip article, wherein molten metal that forms an oxide layer upon contact with air is transferred from a nozzle having a protruding nozzle tip to at least one moving casting surface. Supplying and forming a meniscus with molten metal having a metal oxide surface coating between the end of the tip and the casting surface;
The molten metal is supplied from a tip portion having an inner surface and an end surface that are connected at a linear portion to form an included angle of less than 88 °, and the at least one wall is 0.5 at a portion adjacent to the linear portion. A manufacturing method having a thickness of ˜3 mm, wherein the linear portions are arranged at intervals of 0.5 to 3 mm from one adjacent casting surface during casting.   Final contact between the molten metal and the tip by providing a tip with an inner surface and an end face in contact with the metal having a included angle selected from a range of 15 ° to 80 ° connected by a linear portion The manufacturing method according to claim 19, wherein the molten metal flows from the connecting linear portion to the casting surface.

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