JPS63104751A - Method and apparatus of horizontal continuous casting for metal - Google Patents

Abstract

PURPOSE:To prevent unbalanced cooling to molten metal by inner wall of a mold and ununiformity of lubricating interface by communicating pressure of the fluid existing between cylindrical mold inner wall face and the molten metal body to the outside and executing control of the pressure at the outside. CONSTITUTION:Lubricating oil supplied from an oil supplying pipe 8 is supplied in the mold from many formed slits 13 toward radiated direction after passing through annular distributing flow passage 12 to execute lubrication action. The opening parts 22 communicating the space 20 surrounded by the mold range, in which the molten metal body 15 is formed the pouring hole 11 formed part and the molten metal body 15, are formed as the outside pressure control means. The opening parts 22 gather to the annular passage 24 and the fluid collected from each part of upper and lower and right and left of the mold is mixed and introduced to the outside of mold 1 through one of fluid introduc ing passage 25. A pressure gauge 33 is connected in the fluid introducing pipe 26, to measure the pressure control means is compared with the upper limit value of the beforehand setting pressure in the control unit 34 and in accordance with the result, the motor operated value 32 is closed or opened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an improved horizontal continuous casting process and apparatus for metals, particularly light metals such as aluminum or magnesium or their base alloys.

[Conventional technology]

Generally, in horizontal continuous metal casting, a long ingot in the shape of a cylinder, a prism, or a hollow column is manufactured from molten metal through the following process. In other words, the molten metal enters the tundish that stores the molten metal, passes through a refractory passageway, enters a forcedly cooled cylindrical mold installed almost horizontally, and is cooled here to form a solidified shell on the outer surface of the molten metal body. is formed. A coolant such as water is directly radiated onto the ingot that has been pulled out of the mold, and the ingot is continuously pulled out while solidifying the metal inside the ingot.

Horizontal continuous casting of such metals inevitably involves theoretical difficulties. First, because the mold is installed horizontally, the molten metal inside the mold is pressed against the inner wall at the bottom of the mold by gravity, which creates an imbalance in the cooling of the mold, with stronger cooling at the bottom and weaker at the top. As a result, the final solidification position shifts upward from the axis of the ingot, making it impossible to obtain an ingot with a homogeneous structure.

Second, in order to prevent the molten metal from sticking to the mold wall, lubricating oil is injected from the inner peripheral wall at the inlet end of the mold, but if it is injected uniformly all around the mold inner wall, the lower wall surface will be more The oil tends to flow down and the lubricating interface becomes non-uniform. As mentioned above, in the lower part of the mold, the molten metal and the mold wall are in close contact, and there is no clearance between the solidified shell and the mold wall, so lubricant oil does not flow in and the solidified shell ruptures due to seizing, causing the unsolidified molten metal to flow out. (so-called breakout), resulting in large casting surface defects or, if the process progresses further, casting becomes impossible.

In order to overcome these essential problems in the horizontal continuous casting method of metals, several solutions have been proposed in the past. For example, in Japanese Patent Publication No. 39-23710, the orifice opening for injecting molten metal into the mold is located below the axis of the mold, and in Japanese Patent Publication No. 45-41509, an enclosure is provided at the inlet for molten metal into the mold. This is a measure to direct the flow of high-temperature molten metal downward at the mold entrance, thereby alleviating the downward cooling, and it has the corresponding effect of moving the final solidification position closer to the axial center of the ingot. The problem of shifting liquid contact in molten metal has not been solved, and the homogenization of the ingot structure has been insufficient.

There is also a proposal to change the distribution of the amount of lubricating oil between the upper and lower parts of the mold, as in Japanese Patent Publication No. 46-28889, but due to the effect of gravity acting within the mold, even if a considerable amount of oil is supplied, it will not be uniform. It is difficult to form a lubricating interface.

[Problem that the invention seeks to solve]

The present invention solves the above-mentioned problems in conventional horizontal continuous metal casting, namely, the imbalance in the cooling of the molten metal in the mold and the non-uniformity of the lubricating interface on the inner wall of the mold, thereby achieving homogenization of the ingot structure. An object of the present invention is to provide a method and apparatus for horizontal continuous casting of metal, which can stably cast high-quality ingots by eliminating casting surface defects and breakouts.

[Means for solving problems]

In order to achieve the above object, the inventors of the present invention have made various studies and have failed to realize an improved method and apparatus on a practical scale. Hereinafter, the configuration of the present invention will be explained in detail.

To functionally summarize the method and apparatus of the present invention, the pressure of the fluid that exists between the inner wall surface of the cylindrical mold and the molten metal body on the inflow side of the molten metal into the cylindrical mold for continuous casting using a lubricating fluid supply type. By communicating and transmitting the pressure to the outside and controlling the pressure externally, the unbalance in the cooling of the molten metal by the inner wall of the mold and the non-uniformity of the lubricating interface of the inner wall of the mold are eliminated.

That is, the first aspect of the present invention is to supply a lubricating fluid to a cylindrical mold that is held substantially horizontally and forcibly cooled, and to supply molten metal to one end of the cylindrical mold to form a columnar molten metal body. , in a horizontal continuous metal casting machine in which a columnar ingot formed by solidifying the columnar molten metal body is continuously pulled out from the other end of the cylindrical mold, the molten metal supply side portion of the cylindrical mold and the columnar metal The fluid in the space is led out to the outside and the pressure of the fluid is maintained or maintained outside the space so that the pressure in the space between the outer peripheral surface of the molten metal body and the outer peripheral surface of the molten metal body can be controlled outside the space. It is a horizontal continuous casting method for metals, which is characterized by adjustment.

The second aspect of the present invention is to pour molten metal into the cylindrical mold from a molten metal holding part connected via a fireproof plate to one end of the cylindrical mold which is held substantially horizontally and is forcedly cooled. At least one pouring hole is formed through the refractory plate in a portion extending inward from the inner wall surface of the cylindrical mold, and communicates with a lubricating fluid supply source to lubricate the inner wall of the cylindrical mold. In a horizontal continuous metal casting apparatus in which an opening is formed through and/or adjacent to a wall of a cylindrical mold, a columnar molten metal body may be formed during continuous casting. The area of the planned cylindrical mold, the overhanging part of the fireproof plate,
An opening communicating with the outer peripheral surface of the columnar molten metal body and a space surrounded by the columnar molten metal body is provided, and a pressure regulating mechanism for externally adjusting the pressure of the fluid flowing from the opening to the outside of the cylindrical mold is provided. An apparatus for horizontal continuous casting of metal, characterized in that the apparatus is connected to a conduit communicating with an opening.

It goes without saying that in the present invention, the term "columnar molten metal or columnar ingot" includes a hollow column.

-i In the horizontal continuous metal casting method, there is a gap between the molten metal supply side part of the cylindrical mold (hereinafter referred to as the mold) and the outer peripheral surface of the columnar molten metal body as the molten metal solidifies and contracts. , voids occur. In addition, due to the cooling imbalance peculiar to the horizontal continuous casting method, solidification is accelerated below the mold axis.
Since solidification is suppressed on the upper side, the size of the gap Q changes depending on the vertical position with respect to the mold axis. It is thought that such voids are formed surrounding the outer peripheral surface of the columnar molten metal body, and the properties of such voids are such that after pouring a molten metal such as an Al-Cu alloy as a tracer into the molten metal during casting, the molten metal is rapidly poured into the molten metal. It becomes clear depending on the method of coagulation. The present inventors further fabricated a passage communicating with the above-mentioned void, installed a pressure gauge there, and studied the relationship between pressure and cooling imbalance, and surprisingly found that by adjusting and maintaining the pressure, cooling imbalance could be achieved. We have found that it is possible to solve this problem.

The present invention brings this knowledge to fruition as a means for resolving cooling imbalance, and first, the pressure in the space (hereinafter referred to as corner space) between the inner wall portion of the mold on the molten metal supply side and the outer circumferential surface of the columnar molten metal body is is controllable outside the above space,
The fluid in the space is led out to the outside. In other words, the pressure of the fluid in the corner space is not changed arbitrarily (it can be controlled externally intentionally). Here, the molten metal supply side of the mold These are the inner wall portion of the mold facing the molten metal and its vicinity, and the fluid is led out from the corner space formed by these portions, thereby effectively controlling the pressure. Performing horizontal continuous casting by holding or adjusting the pressure externally in the corner space is also a means of resolving the cooling imbalance. We decided to set the pressure to 100% to ensure its certainty, reliability, and reproducibility.The factor that directly affects cooling imbalance is the pressure that governs the corner space, but it is important to control the pressure outside the corner space. This makes it possible to completely eliminate cooling imbalance.

The liquid or gaseous lubricant used in a horizontal continuous metal casting apparatus of the type described in the preamble of the present patent claims creates pressure in the corner space. In addition,
These lubricants are heated and decomposed by the heat of the molten metal, and may become a thermally decomposed gas. These liquids and (pyrolysis) gases have a lubricating effect between the inner wall surface of the mold and the outer surface of the columnar molten metal body, and according to the findings of the present inventors, their pressure is a factor that affects the cooling balance. . Therefore, by maintaining and adjusting these pressures, the lubricant, which has conventionally been used only as a lubricating means, can also be used as a pressure regulating means. Note that the lubricant will not be described because it is well known and the present invention is not limited in any way by its type. Note that the medium generating pressure in the corner space includes not only lubricant but also a small amount of air, gas released from aluminum, and the like. Also, JP-A-6L-71157
(Japanese Patent Application No. 59-191752), when gas is introduced from the outside, the gas also forms a pressurized space. Regardless of the cause of pressure generation, fluid is communicated from the corner space to the outside, and the pressure of this fluid is maintained and regulated externally.

The pressure outside the corner space can be controlled by the amount of lubricating fluid supplied or the amount of fluid flowing out, provided that the continuous casting conditions are steady conditions and the diameter, length, etc. of the fluid communication tube are constant. That is, as the amount of lubricating fluid supplied increases, the pressure increases, and as the amount of fluid flowing out increases, the pressure decreases. Therefore, an easy-to-operate method for maintaining and adjusting the pressure is to maintain the pressure outside the corner space within a predetermined range by adjusting at least one of the supply amount of the lubricating fluid and the outflow amount of the fluid.

The hydrostatic pressure on the molten metal in the mold is minimum at the top of the mold and maximum at the bottom of the mold. When casting was carried out with the pressure in the corner space maintained at a level higher than the hydrostatic pressure of the molten metal, the molten metal spouted out from the upper part of the mold, or cavities formed inside the ingot. In addition, the fluid passes through the holes penetrating the refractory plate and flows back into the molten metal holding section, causing the molten metal in the holding section to be disturbed by the fluid, which not only makes casting difficult, but also causes metal oxides to form. This contaminated the molten metal and caused a decline in the quality of the ingot. Therefore, the preferred method for maintaining and regulating pressure in the present invention is one that directly targets the pressure in the corner space and maintains the pressure level below the hydrostatic pressure of the molten metal at the level of the top of the inner wall of the cylindrical mold. Specifically, as shown in FIG. 2, the tip of the fluid conducting pipe 26 that communicates with the corner space (not shown) is placed in water 36 in a water tank 35, and the distance of the tip from the water surface is adjusted. By appropriately adjusting the pressure, the hydrostatic pressure applied to the mold-side tip of the fluid conduit 26 is changed, and the pressure in the water tank 35 is increased to be higher than the hydrostatic pressure generated in the corner space (pressure corresponding to the hydrostatic pressure inside the water tank 35). released from the water surface inside. Thus, the pressure of the fluid present in the corner space is regulated.

By the way, the hydrostatic pressure (P) at the level of the top of the mold inner wall
If the level difference between the tanditsu scene and the top of the inner wall of the mold is H (mu), and the specific gravity of the molten metal is ρ, then P=pH. When the pressure in the corner space is measured when the external pressure control according to the present invention has a remarkable effect, this pressure (P, ,
p) is less than the molten metal hydrostatic pressure (P) at the top of the mold inner wall (P
qmw <P). In actual casting, the pressure (p,, t) measured externally is corrected by P*ap, P and the diameter and length of the fluid piping, etc.
<p. In addition, when the molten metal is aluminum or magnesium or a base alloy thereof, P is in the range of 0.2 P to P,
The optimum value is determined by the size of the valley grade ingot and other casting conditions.

Generally, the inner wall surface of a cylindrical mold is made smooth by grinding, polishing, etc. The lower and upper surfaces of the inner wall of the mold are places where the risk of casting defects is highest. Defects that occur in such locations include the following: On the lower surface of the solidified ingot, a striped pattern (wrapping) that occurs periodically in the circumferential direction and bit-like casting surface defects occur, while on the upper surface, there are periodic scale-like patterns and signs that the molten metal has not completely solidified. The external pressure control proposed by the present invention is also effective in preventing casting defects caused by the smooth inner surface of the mold.

Furthermore, if grooves are provided on a portion of the lower surface (bottom surface) and/or upper surface (top surface) of the inner wall surface of the cylindrical mold, which are approximately parallel to the mold axis direction, the cooperative action of external pressure control and the grooves will improve the casting performance. Greater effectiveness in preventing defects is achieved. The lower surface or upper surface of the inner wall surface of the cylindrical mold mentioned above is literal in the case of a prismatic shape such as a sheet slab, but in the case of a cylindrical shape such as a billet, the lower surface or the upper surface of the inner wall surface of the cylindrical mold is an angle of 150 degrees from the axis of the cylindrical mold, respectively.
A circumference within 0 is suitable.

The width of the groove is 0.1 to 1, preferably 0.2 to 0.
．． 5 rings, depth 0.1-11, preferably 0.3-
0.7 The fin pitch (distance between grooves) is O to 10 Tsuru, preferably 3.0 to 7.0 Tsuru. Also, the number of grooves is 1 to 1.
0, preferably 2 to 5. Furthermore, the cross-sectional shape of the groove may be any of those shown in FIGS. 3(a), (b), (c), (d), and (e). Furthermore, the length of the groove does not need to be as long as the entire length of the mold, and the effect of the groove will appear if it exceeds a certain value. According to experiments conducted by the present inventor, a sufficient effect is obtained when the number is 158 or more. The width and depth of the grooves mentioned above,
If the number of grooves is less than the lower limit, no significant effect will be observed compared to a smooth mold. If the width, depth, and number of grooves exceed the upper limits, the lubricating fluid passes through the grooves and flows out more than necessary, which impairs the lubrication effect and causes casting troubles due to insufficient lubrication, which is undesirable. When the groove pinch exceeds the upper limit, no significant effect is observed compared to a smooth mold.

These grooves do not have to be straight; even a slight trigonometric curve has the effect of influencing the passage of lubricating fluid and reducing casting defects. It is not preferable for the curved groove to form an extremely large angle with respect to the casting direction (or mold axis direction), since this will adversely affect the passage of lubricating fluid.

[For production]

The present inventors consider the effect that the external pressure control proposed by the present invention has on the upper and lower cooling (unbalance) in horizontal continuous casting as follows.

In horizontal continuous metal casting, vegetable oils such as castor oil or animal oils such as grease are generally used to lubricate the molten metal and the inner walls of the mold. Most of these lubricating oils act as fluid lubricants, but some evaporates into gaseous form and forms gas pockets in the corner spaces. Since this gas is continuously generated as the lubricating oil is supplied, it is released in the casting direction from a small gap between the contact surface between the mold and the ingot during casting.

Assuming that the gap will be larger on the upper side of the ingot due to the gravity acting on the ingot, it is expected that the amount of gas released will be larger on the upper side of the ingot. By the way, when the amount of lubricating oil is excessively increased, unsolidified molten metal often blows out violently from the upper part of the ingot immediately after the end of the mold, making casting operations impossible. Corner space pressure at this time (Pgmp
) was found to be significantly higher than the pressure during stable operation. In addition, it has been observed that when the amount of lubricating oil increases until just before the molten metal blows out, huge cavity defects occur inside the obtained ingot, and this fact indicates that the lubricating oil evaporates and gases It can be seen that the excess gas forming the pool does not escape through the gap between the contact surface of the mold and the ingot, but enters into the molten metal.

On the other hand, if the amount of lubricating oil is reduced more than necessary, although the pressure inside the gas reservoir will decrease, the lubricating effect will be lost, and the molten metal will seize on the inner wall of the mold, increasing the resistance to pull out the ingot in the casting direction, and causing the solidified shell to crack. Not only will casting defects occur, but the solidified shell will eventually break and the molten metal will blow out.
out), the ingot breaks and becomes uncastable.

As mentioned above, if the amount of lubricating oil is too large, casting becomes unstable, while if it is too small, casting becomes difficult. Subtle changes in casting conditions due to changes in water, oxidation, deterioration of the refractory plate, etc. can eliminate the cooling imbalance of horizontal continuous casting and produce ingots of good quality in a stable manner over a long period of time. making it difficult to do so.

Considering the above from the perspective of gas pressure adjustment, even in the conventional method, gas is released in the casting direction from a small gap between the contact surface between the mold and the ingot, so the pressure in the corner space is affected by the size fluctuation of the gap. However, such naturally occurring pressure adjustments cannot cope with the large and/or rapid pressure increases that occur during casting operations, leading to inability to cast, or more moderate pressure increases. This is thought to have caused poor casting surfaces and internal defects in the ingots. On the other hand, being able to influence the pressure of the gas reservoir (corner space) in a controllable manner from the outside would be effective, appropriate, and quick in responding to any fluctuations in conditions that may occur during casting operations. It is possible to respond to

Hereinafter, the first part showing a preferable casting apparatus for carrying out the method of the present invention will be described.
The present invention will be explained in more detail with reference to the drawings.

〔Example〕

In FIG. 1, reference numeral 1 denotes a mold 1 which is held almost horizontally and is forcibly cooled by cooling water 2 in a mold cooling water cavity 4, and one end of which is connected to a tundish ( (not shown) are connected. The molten metal held in the molten metal holding portion in the tundish is cast into a mold through the molten metal inlet or pouring hole 11 of the refractory plate-like body 10. At least one pouring hole 11 is formed in a portion of the refractory plate-like body 10 projecting inward from the mold 1. 8
is an oil supply pipe for supplying lubricating oil, and the lubricating oil supplied from here passes through an annular distribution channel 12 formed concentrically with respect to the mold axis 20, and then passes through an annular distribution channel 12 formed in large numbers in the radial direction. The mold extends from the slit 13 into the mold, and achieves the lubricating effect as described above. The method for forming the lubricating oil flow path is not limited to the one shown in the drawings, but includes a method of providing an opening that penetrates the mold inner wall 21, and a method of using the side surface of the mold of the fireproof plate-like body 10 as an oil flow path, although this is not preferred. etc. is optional.

15 is a molten metal body, 17 is a solidification interface that is a boundary between this and a solidified portion, and 16 is an ingot.

18 is an O-ring that prevents lubricating oil from leaking.

According to the feature of the present device invention, the mold area where the molten metal body 15 is to be formed, the overhanging portion of the refractory plate 10 (portion where the pouring hole 11 is formed), and the molten metal body 15 An opening 22 communicating with the enclosed space (corner space) 30 is formed as one of the external pressure control means. In addition to the opening 22 that penetrates the mold inner wall 21, the opening 22 is installed at one or more locations on the joint surface between the mold 1 and the refractory plate 10, or on the refractory plate 21. be able to. Further, the opening 22 may be a hole or slit-shaped hole with a V-shaped cross section and a groove path obtained by mechanical processing, or a porous material may be formed on the inner wall of a mold or on a fire-resistant plate. It is also possible to embed it in a hole, etc., and use it as an opening.

The installation position of the opening 22 is close to the end of the mold on the drawing side,
If there are many opportunities for contact with molten metal, the opening 22 must be large enough to prevent the molten metal from penetrating into the opening 22. Its size is 41 x 20 x 11 or less in thickness or diameter.

The openings 22 are formed as a number of radial slits around the entire circumference of the mold 1. In this way, it is preferable that the openings 22 be installed around the entire circumference, but even if the installation position is limited to the upper part of the mold where there is a large gas pool, if the external pressure is adjusted appropriately, the effect will be the same as when the openings 22 are installed around the entire circumference. It's not much different than the case. The opening 22 may be installed at any position as long as it does not interfere with the supply of lubricating oil and allows fluid to be led out. For example, the slits 13 may be used alternately for lubricating oil supply and fluid extraction. However, slit 1
It is necessary to increase the distance between 3.

The openings 22 converge into an annular passageway 24 in which fluids collected from the upper, lower, left and right portions of the mold are mixed. Furthermore, the fluid is led out of the mold 1 through a single fluid conduction portion 25 branched from the annular passage 24. A conduit (fluid conduit 26) is connected to the fluid conduit 26 to sequentially lead out of the mold the fluid that continues to be generated as the casting progresses. A pressure gauge 33 is connected to the fluid conduit 26 to measure the pressure inside the conduit. An oil trap 2 is provided in the middle of the fluid conduction pipe 26 to capture lubricating oil that has entered the pipe together with the gas.
7 so that the oil 28 does not flow into the downstream fluid conduction pipe 26, and the pressure gauge 33 is installed at this location, the accuracy of fluid pressure measurement is improved.

Other external pressure control means are comprised of 32, 33, and 34, and perform pressure control as follows. The measured pressure is the upper limit of pressure (
The pressure (equivalent to the molten metal hydrostatic pressure in the corner space) is compared, and the electric valve 32 is shut off or opened depending on the result.

As shown in FIG. 2 instead of an electric valve, the end of the fluid conduction pipe 26 equipped with an oil trap 27 is immersed in a water tank 35 storing water 36, and the immersion depth of the fluid conduction pipe 26 is set to h). By setting the pressure to the upper limit value in advance, excess pressure of the fluid is released from the end of the fluid conducting pipe 26.

Additionally, if the pressure is too high, it can be reduced using a pump or the like.

In the present invention, when performing control to maintain fluid pressure, for example, maintain a predetermined pressure based on molten metal hydrostatic pressure, and when adjusting fluid pressure, 'Xc lubricating oil supply amount or the above fluid outflow amount is Make adjustments. These maintenance and adjustments may be selected as appropriate; for example, the pressure may be maintained during a certain period of operation, and the pressure may be adjusted during another period.

Furthermore, the present invention will be explained in more detail with reference to operational experimental examples.

Example 1 An aluminum alloy containing 12% Si, 3% Cu, and 0.4% Mg was horizontally continuously cast into a billet having a diameter of 36n+ under the following conditions.

(1) Level difference between the molten metal level in the tundish and the top of the mold inner wall: 160 m (2) Lubricating oil type: Castor oil (3) Lubricating oil supply amount: 0°5 m//m1n (4) Casting speed: 0.5 m /lll1n (5) Cooling water supply amount:
201/win (6) Tandish (average molten metal temperature): 670°C The system through which the fluid flows was configured as follows.

(1) How to release excess pressure: See Figure 2.

(2) Water immersion depth of the fluid conduit: 200mm (The pressure in the corner space is set to a maximum of 200mmAq, and any excess pressure beyond that is released in the form of bubbles from the tip of the fluid conduit). Flow system)' (3) Internal diameter of fluid conduit: 61 mm; Length of fluid conduit from mold to water tank: 1500 m After casting starts, bubbles are released from the water tank, and the pressure is 170 mAq.
The pressure still dropped once, but soon after that the pressure rose to 200mA.
The temperature rose to q and bubble emission started again.

This pressure was maintained during the entire subsequent casting process.

Casting was extremely stable and was carried out without any operational problems such as molten metal spouting or splintering.

The obtained ingot exhibited an extremely smooth casting surface with no wrapping or pit-like defects on the entire outer peripheral surface, and no cavity defects were present inside the ingot.

(Comparative Example) Horizontal continuous casting was carried out under the same conditions as in the example without configuring the fluid flow system (pressure adjustment in the corner space using a water tank) described in the example.

In the horizontal continuous casting of this comparative example, the casting is unstable;
There was a change in the casting surface. During long casting, molten metal spouted out, so adjustments were made to reduce the amount of lubricant supplied and/or slow the casting speed to avoid operational troubles.

However, when the obtained ingot was observed with the naked eye, deep lapping occurred continuously in the casting direction on the lower surface of the casting surface, and large and small pinholes were scattered. On the top surface of the cast surface,
A periodic scale-like pattern or a ripple-like pattern caused by the molten metal being blown out by the lubricating oil gas was occurring. Also,
Molten metal sometimes spewed out from the end of the mold in the casting direction, making casting impossible.

Example 2 An aluminum alloy having the same composition as Example 1 was horizontally continuously cast into a billet with a diameter of 351 layers under the following conditions.

(1) Level difference between the molten metal level in the tundish and the upper surface of the mold inner wall: 16ONM (2) Lubricating oil type: Castor oil (3) Lubricating oil supply amount: 0.5 cc 7mln (4)
Casting speed: 500 m/rain (5) Cooling water supply amount: 2012/win (6) Average temperature of molten metal in tundish: 670°C (7) How to release excess pressure: (8) Fluid conduction pipe according to Fig. 2 Water immersion depth: 200mm (9)
The internal diameter of the fluid conduit was 26mm, the length of the fluid conduit from the mold to the water tank was 1500 m.The conditions for the grooves on the inner surface of the mold were as follows.

(1) Main distribution and pitch of grooves: 3 - pitch 51 (2) Semi-drilling position: Lower surface of mold inner wall surface (3) Cross-sectional shape of groove: Fig. 4 (a) - Partial plan view of mold inner surface, The same figure (b) shows the groove shape. In the figure, 40 is a groove, 41
Continuous casting was carried out under the above conditions in which the cooling water is spouted. The casting was performed stably over a long period of time, and compared to Example 1, there was no lapping of the ingot at the part corresponding to the bottom surface of the mold. and pit is 2
et al; Ward 1; ht;.

Example 3 An aluminum alloy according to JIS 2218 was horizontally continuously cast into a billet having a diameter of 67 mm under the following conditions.

(1) Level difference between the molten metal level in the tundish and the upper surface of the mold inner wall: 1300 (2) Lubricating oil type: Castor oil (3) Lubricating oil supply amount: 10 cc/win (4) Casting speed = 450 m/+win (5) Cooling Water supply amount = 3
5 It /+*1n (6) Average temperature of the molten metal in the tundish: 2690°C (7) How to release excess pressure: According to Figure 2 (8) Water immersion depth of the fluid conduit: 280 m (9) Fluid conduit Inner diameter: 6 mm, length of fluid conduction pipe from the mold to the water tank: 1500 mm The conditions for the grooves on the inner surface of the mold were as follows.

(1) Number of grooves and pitch: 5, pitch 7 (2) Drilling position M: Upper surface of inner wall of mold (3) Cross-sectional shape of groove: Fig. 5 (4) Length of groove: Total length of mold 30111 The results of continuous casting in this example were as good as in Example 2, with casting defects drastically reduced.

〔Effect of the invention〕

As is clearer from the above description, especially from the examples, if the method and apparatus of the present invention are applied to the horizontal continuous casting of metals, especially light metals such as aluminum or its alloys, the obtained ingot can be made more whole than in the conventional method. It becomes smooth and uniform around the circumference. Therefore, less cutting and removal of the ingot skin is required.

One of the causes of defects that require peeling and removal when an ingot is used as a product is the vaporization of the lubricating oil or lubricating oil used to prevent the molten metal from sticking to the mold. The pressure of the generated gas is undesirable. If the amount of lubricating oil is increased more than the appropriate amount, the number of defects will increase and the molten metal will often blow out from the end of the mold, making it impossible to cast. On the other hand, if the amount of lubricating oil is too small, seizure will occur instantly. Therefore, it was difficult to adjust the amount of lubricating oil, and the range of suitability was narrow.

The mold having the grooved inner surface of the present invention reduces lubricant amount sensitivity and makes casting defects less likely to occur over a wide lubrication amount range, contributing to stable operation. Furthermore, since the inside of the ingot obtained by the present invention is sound, the reliability of the product is high (and the manufacturing yield is high).As described above, the present invention greatly contributes to the improvement of the horizontal continuous casting method.

[Brief Description of the Drawings] Fig. 1 is a vertical cross-sectional view of a horizontal continuous casting apparatus showing an embodiment of the present invention, and Fig. 2 shows a situation in which the pressure is adjusted by releasing bubbles of the drawn fluid from a water tank. FIG. Figures 3 (A), (B), (C), (D), and (E) are drawings showing the cross-sectional shapes of the grooves on the inner surface of the mold, and Figures 4 (A) and (B) are those of Example 2. Drawings showing the inner surface of the mold used and the cross-sectional shape of the grooves; FIG. 5 is a drawing showing the cross-sectional shape of the grooves of the mold used in Example 3. 1... Cylindrical mold, 2... Cooling water, 3...
Cooling water supply pipe, 8... Oil supply pipe, 10... Fireproof plate-like body, 11... Molding port, 13... Slit,
15... Molten metal body, 16... Ingot,
21... mold inner wall surface, 22... opening,
24... Annular passage, 25... Fluid conduction part,
26... Fluid conduction pipe, 30... Corner space (gas pool).

Claims (1)

[Claims] 1. Supplying a lubricating fluid to a cylindrical mold that is held substantially horizontally and forcibly cooled, and supplying molten metal to one end of the cylindrical mold to form a columnar molten metal body; In a horizontal continuous metal casting method in which a columnar ingot formed by solidifying the columnar molten metal body is continuously pulled out from the other end of the cylindrical mold, the molten metal supply side portion of the cylindrical mold and the columnar metal The fluid in the space is led out to the outside and the pressure of the fluid is maintained or maintained outside the space so that the pressure in the space between the outer peripheral surface of the molten metal body and the outer peripheral surface of the molten metal body can be controlled outside the space. A horizontal continuous casting method for metals that is characterized by adjustment. 2. The horizontal continuous casting method for metals according to claim 1, wherein the pressure of the fluid is created by one or more of liquid or gas lubricants, or thermally decomposed gases thereof. 3. Claim 1, wherein the external pressure of the fluid is maintained within a predetermined range by adjusting at least one of the supply amount of the lubricating fluid and the outflow amount of the fluid. or the horizontal continuous casting method of metal as described in paragraph 2. 4. The method for horizontal continuous casting of metal according to claim 3, wherein the pressure of the fluid in the space is maintained below the hydrostatic pressure of the molten metal at the level of the top of the inner wall of the cylindrical mold. . 5. Claims characterized in that the molten metal is aluminum, magnesium, or a base alloy thereof, and the pressure of the fluid in the space is maintained at 20 to 100% of the hydrostatic pressure of the molten metal. 4. Horizontal continuous casting method of metal according to the fourth aspect. 6. At least one step of pouring molten metal into the cylindrical mold from a molten metal holder connected to one end of the cylindrical mold held substantially horizontally and forcibly cooled through a refractory plate. Molten pouring holes are formed through a portion of the refractory plate that extends inward from the inner wall surface of the cylindrical mold, and an opening that communicates with a lubricating fluid supply source to lubricate the inner wall of the cylindrical mold is formed. , in the horizontal continuous metal casting apparatus, which is formed through the wall of the cylindrical mold and/or adjacent to the wall, a columnar molten metal body is expected to be formed during continuous casting. An opening is provided that communicates with a space surrounded by a region of the cylindrical mold, an overhanging portion of the refractory plate, and an outer peripheral surface of the columnar molten metal body, and the opening 1. A horizontal continuous metal casting apparatus, characterized in that a pressure regulating mechanism for externally regulating the pressure of the fluid flowing to the outside is connected to a conduit communicating with the opening. 7. The metal according to claim 6, characterized in that the opening for communicating the fluid is provided at the top of the inner wall surface of the cylindrical mold and/or on the wall surface of the top top of the space. Horizontal continuous casting equipment. 8. Claims characterized in that the opening for communicating the fluid is a slit having an open end between the connecting surfaces of the cylindrical mold and the refractory plate or on the inner wall surface of the cylindrical mold. The horizontal continuous metal casting apparatus according to item 6 or 7. 9. The method according to claim 6 or 7, wherein the opening is made of a fluid permeable member fixed to the inner wall surface of the cylindrical mold or the plate surface of the refractory plate. Horizontal continuous metal casting equipment. 10. An opening that penetrates the inside of the body of the cylindrical mold and opens on the inner wall surface of the entire periphery communicates with an annular path inside the body of the cylindrical mold, and further, the annular path is connected to the outside of the cylindrical mold. 9. The horizontal continuous metal casting apparatus according to any one of claims 6 to 9, characterized in that the apparatus is connected to a conduit provided with a pressure regulating mechanism. 11. The horizontal continuous metal casting apparatus according to claim 10, wherein the pressure regulating mechanism operates a valve attached to the conduit. 12. The pressure regulating mechanism is characterized by having a control unit that converts the measured pressure of the pressure regulating mechanism into the hydrostatic pressure of the molten metal at the upper end of the space and compares the converted pressure with the hydrostatic pressure. A horizontal continuous metal casting apparatus according to claim 11. 13. Any one of claims 5 to 12, characterized in that the top and/or bottom of the inner wall surface of the cylindrical mold is provided with a groove extending substantially in the axial direction of the mold. Horizontal continuous casting equipment for metals as described in paragraph.