JP5021199B2 - Horizontal continuous casting apparatus, horizontal continuous casting method, and aluminum alloy casting rod - Google Patents

Description

  In the present invention, a heat insulating member having a pouring passage is interposed between the tundish and the mold, and the molten alloy in the tundish is supplied from the pouring passage to the casting mold to produce an aluminum alloy casting rod. The present invention relates to a continuous casting apparatus, a horizontal continuous casting method, and an aluminum alloy casting rod.

  In recent transportation equipment, aluminum alloy parts are increasingly used due to the demand for weight reduction. Such an aluminum alloy part is obtained by cutting an aluminum alloy bar to a predetermined length to form a forging material, and forming the forging material into a part by forging. The aluminum alloy bar is manufactured by, for example, subjecting a material produced by horizontal continuous casting to plastic working or heat treatment.

  In this horizontal continuous casting, generally, a cylindrical, prismatic or hollow column-shaped long ingot is produced from a molten metal through the following process. That is, the molten metal in the tundish that stores the molten metal passes through the refractory passage and then enters the cylindrical mold installed almost horizontally, where it is forcibly cooled and solidified on the outer surface of the molten metal body. Is formed. Further, a coolant such as water is directly radiated to the ingot drawn from the mold, and the ingot is continuously drawn while solidification of the metal proceeds to the inside of the ingot.

  In this horizontal continuous casting, lubricating oil is injected from the inner peripheral wall on the inlet side of the mold to prevent seizing of the molten metal on the mold wall. In this mold, the lubricating oil is pushed up from the lower wall surface to the upper wall surface due to the difference in gravity applied to the upper and lower surfaces of the ingot. The cracked gas generated by heating the lubricating oil also rises to the upper wall surface. Due to such factors, the lubrication state between the inner peripheral wall of the mold and the solidified shell of the molten metal or the outer peripheral surface of the ingot is uneven on the upper and lower sides of the mold.

  For example, below the mold, lubricating oil does not flow between the inner wall of the mold and the molten metal or solidified shell, and the molten metal seizes on the inner wall of the mold, so the solidified shell is broken and the unsolidified molten metal flows out. If it becomes defective or goes further, the ingot is broken and the casting operation becomes impossible. On the other hand, there is an excess of lubricating oil above the mold, and since the contact between the molten metal and the inner peripheral wall of the mold is not intimate, the molten metal is not sufficiently cooled by the mold, and the unsolidified molten metal is removed from the upper part of the ingot. It will blow out.

In order to overcome such an essential problem in the horizontal continuous casting of metal, various solutions have been proposed in the past, such as the following Patent Documents 1, 2, and 3.
Japanese Patent Publication No. 8-32356 Japanese Patent Laid-Open No. 11-170009 Japanese Patent Laid-Open No. 11-170014

  Of the above Patent Documents 1, 2, and 3, Patent Documents 1 and 2 relate to the lubricant supply, and Patent Document 3 relates to the uniformization of the molten metal temperature distribution in the mold.

  Patent Document 1 discloses a problem in conventional horizontal continuous casting of metal, that is, an unbalance of the cooling of the molten metal in the mold and a non-uniformity of the lubrication interface on the inner wall of the mold. In order to provide a horizontal continuous casting method and apparatus for metal capable of stably casting good quality ingots by eliminating defects and breakouts, a cylindrical mold that is held almost horizontally and forcedly cooled A lubricating fluid is supplied to the cylindrical mold, a molten metal is supplied to one end of the cylindrical mold to form a columnar molten metal body, and a columnar ingot formed by solidifying the columnar molten metal body is used as the cylindrical mold. In the horizontal continuous casting method of the metal drawn from the end, the lubricating fluid is infiltrated into the porous voids of the permeable porous mold part formed on the inner wall surface of the cylindrical mold, and the metal facing the unsolidified or solidified metal melt Moisture the inner wall of the cylindrical mold While continuously leaching the fluid, a gas mainly composed of the lubricating fluid and / or a decomposition gas of the lubricating fluid is passed through a groove formed on the inner wall surface of the cylindrical mold, and the ingot drawing end of the mold And the amount of leaching of the lubricating fluid to the upper portion of the permeable porous mold portion is adjusted to be smaller than the amount of leaching to the lower portion of the permeable porous mold portion.

  Further, in Patent Document 2, in the horizontal continuous casting method of aluminum or aluminum alloy, an appropriate amount of lubricating oil is uniformly distributed in the inner peripheral direction of the mold, thereby improving the surface properties of the ingot and reducing the back segregation layer. In order to reduce the thickness, reduce the amount of peeling, and improve the yield, a plurality of lubricating oil supply holes are provided in the inner surface of the upper half of the mold, The outer peripheral unit length is 0.001 to 0.012 cc / min · mm per minute, and a self-lubricating carbon sleeve fitted to the inner surface of the cooled mold by shrink fitting or the like may be used. It is disclosed.

  In Patent Document 3, the temperature distribution of the molten metal inside the mold is made uniform, thereby reducing the molten metal boundary at the bottom of the ingot, reducing the thickness of the reverse segregation layer formed on the ingot surface, and peeling the ingot. For the purpose of reducing the amount and improving the yield, and at the same time, suppressing the occurrence of breakout, the molten metal supply port for the molten metal inlet that supplies molten metal from the furnace to the mold is within the range below the center position of the mold cross section. The horizontal continuous casting apparatus is disclosed in which the cross-sectional area is 10 to 25% of the entire cross section of the mold.

  By the way, in recent years, in order to perform a stable production operation by horizontal continuous casting, a situation has arisen in which a large amount of lubricant must be supplied and lubricated. For example, while the demand for aluminum alloy parts is increasing, it is desired to increase the productivity of the aluminum alloy bar material, which is required to increase the casting speed. Therefore, it is necessary to prevent the seizure by increasing the supply amount of the lubricant compared to the conventional method.

  However, as described above, when a large amount of lubricant is introduced, there is a problem that breakout occurs due to excessive vaporized gas, or that the lubricant is in contact with the excess lubricant and molten metal, resulting in a lubricant reaction product. There was a problem that the ingot was defective.

  The present invention has been proposed in view of the above, and even if the lubricant is reduced, high-speed casting can be performed stably and smoothly, and the occurrence of breakout and lubricant reaction products is also suppressed, resulting in poor ingots. It is an object of the present invention to provide a horizontal continuous casting apparatus, a horizontal continuous casting method, and an aluminum alloy cast bar that can greatly reduce the amount of aluminum.

In order to achieve the above object, the present invention provides a horizontal continuous casting apparatus for producing an aluminum alloy casting rod by supplying molten alloy in a tundish from one end of a horizontally arranged mold into the mold. The pouring passage is formed in a heat insulating member disposed between the mold and one end of the mold and communicates the tundish with the mold. The amount of lubricating oil supplied from the annular lubricant supply port provided on the inner peripheral wall of the mold is not more than 0.24 g / min. The hot water passage is characterized in that its contour includes a lower semicircular shape.

Also, it disposed between the one end of the tundish and the mold, and the heat insulating member having a pouring passage communicating the tundish and the mold, disposed in a direction substantially perpendicular to the heat insulating member, and notes the heated water passage And a partition layer having an integral through hole.

In addition , a heat insulating member is interposed between one end of the mold and the partition layer.

Further, the partition plate is hole-side peripheral portion is bent horizontally faces the one end of the mold, is characterized in that.

Also, among the heat-insulating member interposed between the one end and the partition layer above the mold, the area of the heat insulating member facing the hollow portion of the mold, and 40% to 85% by area relative to the longitudinal area of the hollow portion of the mold It is characterized by that.

In addition , the partition layer is formed of a lubricant and a material that does not allow vaporized lubricant to pass through.

Further , the lubricant supply port provided on the inner peripheral wall of the mold near one end of the mold is extended to the vicinity of the other end of the mold.

In the present invention, the lubricant supply port provided on the inner peripheral wall of the mold near one end of the mold may be branched and provided near the other end of the mold.

In addition , the molten alloy of the aluminum alloy is characterized in that the magnesium content is 0.5% by mass or more.

Moreover , the component of the molten alloy of the aluminum alloy is Si (content 0.05 to 1.3% by mass), Fe (content 0.1 to 0.7% by mass), Cu (content 0.1 to 0.1%). 2.5% by mass), Mn (content 0.05 to 1.1% by mass), Mg (content 0.8 to 3.5% by mass), Cr (content 0.04 to 0.4% by mass) ) And Zn (content 0.05 to 8% by mass or less).

Furthermore, the present invention provides a horizontal continuous casting method for producing an aluminum alloy casting rod by supplying molten alloy in a tundish from one end of a horizontally arranged mold into the mold, and between the tundish and one end of the mold. The pouring passage formed between the tundish and the mold and the mold is positioned in a heat insulating member disposed at the position of the pouring passage inner diameter lower position than the mold inner diameter lower position. The solidified shell is formed from the lower part of the ingot in the mold so that it is 8% or more upward, and the amount of lubricating oil supplied from the annular lubricant supply port provided in the inner peripheral wall of the mold is It is 0.24 g / min or less, and the pouring passage is characterized in that the contour includes a lower semicircular shape.

In addition , a partition layer having a through hole integral with the pouring passage is provided in a heat insulating member that is disposed between the tundish and one end of the casting mold and has a pouring passage that communicates the tundish and the casting mold. The horizontal continuous casting is performed while the lubricant that is supplied to the mold at the time of casting and exudes to the heat insulating member is blocked by the partition layer.

In addition , the lubricant supply port provided on the inner peripheral wall of the mold near one end of the mold is expanded to the other end of the mold, and the lubricant is also supplied to the other end of the mold during horizontal continuous casting. It is a feature.

In the present invention, the lubricant supply port provided on the inner wall of the mold near one end of the mold is branched and provided near the other end of the mold, and lubricates near the other end of the mold during horizontal continuous casting. Material may be supplied .

And this invention is an aluminum alloy casting rod, Comprising: It manufactured using one of the horizontal continuous casting methods mentioned above .

In the present invention, the pouring passage formed in the heat insulating member and the mold are positioned so that the pouring passage inner diameter lower position is 8% or more of the mold inner diameter lower than the mold inner diameter lower position. In addition, since the pouring passage has a lower semicircular shape in its outline, the pouring passage is positioned below the inner diameter of the mold in order to make the temperature balance of the conventional ingot uniform. Compared to the case, the temperature of the molten alloy supplied to the lower end of one end of the mold is lowered, so that solidification shell formation at the lower part of the ingot is performed quickly, and provided on the inner peripheral wall of the mold, Since the lubricant supply amount from the annular lubricant supply port is 0.24 g / min or less, stable casting can be performed even if the lubricant supply amount is reduced. Therefore, high-speed casting can be performed stably and smoothly even if the lubricant is reduced. In addition, since the temperature of the molten alloy supplied to the lower part at one end of the mold is lowered, the gasification of the lubricant can be suppressed and the occurrence of ingot defects due to the gasified lubricant being caught in the ingot is prevented. can do.

In addition , a partition layer is provided on the heat insulating member, and the lubricant that is supplied to the mold and oozes into the heat insulating member is blocked by the partition layer, so that the lubricant reacts with the molten alloy or wraps around the tundish side. This can prevent the wasteful consumption of the lubricant and reduce the lubricant. Therefore, high-speed casting can be performed stably and smoothly even if the lubricant is reduced. Moreover, the lubricant reaction product generated on the peripheral wall of the heat insulating member and the vicinity thereof is not generated, and the ingot defects can be greatly reduced.

  In addition, blocking the lubricant that has been supplied to the mold and oozed into the heat insulating member with the partition layer means that the lubricant that has reached the partition layer from the mold side reacts with the molten alloy or wraps around the tundish side. In the case where it can be prevented, or even if not completely prevented, it includes the extent to reduce wasteful consumption due to reaction with molten alloy and wrapping around the tundish side.

In addition , since a heat insulating member is interposed between one end of the mold and the partition layer, even when a partition layer that easily transfers heat is provided, the molten alloy can be supplied to the mold while maintaining heat. . Therefore, the solidification position of the molten alloy in the mold is properly maintained, and stable casting can be performed.

In addition , since the periphery of the through hole side of the partition layer is horizontally bent so as to face one end of the mold, the heat insulating member between one end of the mold and the partition layer is also used in the molten metal in the portion of the pouring passage. Do not contact with. Therefore, reaction of the lubricant with the molten alloy through the heat insulating member and wraparound to the tundish side can be more reliably prevented.

Moreover , the area of the heat insulation member which faces the hollow part of a casting_mold | template among the heat insulation members interposed between the end of a casting_mold | template and a partition layer was 40 to 85% by area ratio with respect to the longitudinal cross-sectional area of the hollow part of a casting_mold | template. Therefore, the heat insulation member having an area necessary for heat insulation will surely face the hollow portion of the mold. For this reason, even if the molten alloy is supplied to the mold, it is possible to prevent the heat of the molten alloy from being released from one end side of the mold and released and cooled. Therefore, the solidification position of the molten alloy in the mold is properly maintained, and stable casting can be performed.

Further , since the lubricant supply port provided on the inner peripheral wall of the mold near one end of the mold is extended to the other end of the mold, the lubricant can be supplied also from the other end of the mold. In the case of high-speed casting, the ingot solidification position tends to move to the other end of the mold, and in order to supply lubricant to the other end, conventionally, a larger amount of lubricant is supplied near one end of the mold. However, by extending the lubricant supply port, the lubricant can be supplied accurately at a position near the other end. That is, since an appropriate amount of the lubricant is supplied to the necessary portions, unnecessary lubricant is not supplied, and high-speed casting can be performed stably and smoothly even if the lubricant is reduced.

Incidentally, it is possible to supply branches the lubricant supply port provided in the mold inner peripheral wall of the one end side of the mold lever also provided on the other end side of the mold, the lubricant from the other end side of the mold. In the case of high speed casting, etc., the ingot solidification position tends to move to the other end of the mold, and in order to supply the lubricant to the other end, conventionally, a larger amount of lubricant is required near one end of the mold. Although it was supplied, the lubricant can be supplied accurately at a position near the other end by the branch of the lubricant supply port. That is, since an appropriate amount of the lubricant is supplied to the necessary portions, unnecessary lubricant is not supplied, and high-speed casting can be performed stably and smoothly even if the lubricant is reduced.

And since the above-mentioned present invention was applied to the casting of an aluminum alloy having a magnesium content of 0.5% by mass or more, the casting of the magnesium-containing aluminum alloy, which was difficult to stably cast without increasing the amount of the conventional lubricant. Even so, the same effects as in high-speed casting, such as reduction of lubricant, suppression of generation of lubricant reaction products, stable smooth casting, and prevention of ingot defects, should be exhibited. Can do.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  First, an aluminum alloy casting rod will be described. The aluminum alloy casting rod according to the present invention is a horizontal continuous casting method that uses a cylindrical mold that is held so that the central axis is substantially horizontal (substantially horizontal is the lateral direction) and is provided with forced cooling means. And the diameter can be in the range of 10 mm to 100 mm. Although it is possible to deal with other than this diameter range, the equipment for industrial processes such as forging, roll forging, drawing, rolling, impact processing, etc. is made small and inexpensive industrially. For this reason, the diameter is preferably in the range of 10 mm to 100 mm. When casting by changing the diameter, it can be handled by exchanging with a removable cylindrical mold having an inner diameter corresponding to the diameter, and changing the melt temperature and casting speed accordingly. Change the cooling water and lubricating oil settings as necessary.

  This aluminum alloy cast bar is used as a raw material for post-process plastic processing, for example, forging, roll forging, drawing, rolling, impact processing and the like. Alternatively, it is used as a material for machining such as bur machining and drilling.

  Next, an example of the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a view showing an example of the vicinity of a mold of the horizontal continuous casting apparatus of the present invention. In the figure, the tundish 250, the refractory, and the molten alloy 255 stored in the tundish 250 are supplied to the cylindrical mold (hereinafter simply referred to as “mold”) 201 through the refractory plate-like body 210. A product plate-like body 210 and a mold 201 are arranged. As will be described in detail later, the refractory plate-like body 210 includes a first heat insulating member 2a, a second heat insulating member 2b, and a partition layer 2c. The mold 201 is held so that the mold center axis 220 is substantially horizontal. A forced cooling means for the mold 201 is disposed inside the mold 201, and a forced cooling means for the solidified ingot 216 is disposed at the outlet of the mold 201 so that the molten alloy 255 becomes the solidified ingot 216. In FIG. 1, a cooling water shower device 205 is provided as an example of means for forcibly cooling the solidified ingot 216. In the vicinity of the outlet of the mold 201, a drawing drive device (not shown) is installed so that the solidified ingot 216 that has been forcibly cooled is drawn at a constant speed and continuously cast. Furthermore, a synchronized cutting machine (not shown) for cutting the aluminum alloy cast rod drawn continuously into a predetermined length is provided.

  As shown in FIG. 1, the mold 201 cools the mold wall surface through the cooling water 202 in the mold cooling water cavity 204, so that the heat of the columnar metal melt 215 filled in the mold 201 is brought into contact with the mold 201. A forced cooling means for the mold that forms a solidified shell on the surface of the mold, and a cooling water is discharged from the cooling water shower device 205 so that the cooling water is directly applied to the solidified ingot 216 at the end of the mold outlet. This is a mold having forced cooling means for solidifying the molten metal 215. Further, the mold 201 is connected to the tundish 250 through a refractory plate-like body 210 at one end opposite to the jet port of the cooling water shower device 205. In FIG. 1, cooling water for forcibly cooling the mold 201 and cooling water for forcibly cooling the solidified ingot 216 are supplied through a common cooling water supply pipe 203. Cooling water can also be provided.

  It is preferable that the forced cooling means of the mold 201 and the cooling water shower device 205 can be controlled by a control signal.

  The effective mold length (from the position where the extension line of the central axis of the outlet of the cooling water shower device 205 hits the surface of the solidified ingot 216 cast to the contact surface between the mold 201 and the refractory plate-like body 210 is determined. This effective mold length L is preferably 15 mm to 70 mm. If the effective mold length L is less than 15 mm, casting becomes impossible because a good film is not formed. If it exceeds 70 mm, there is no effect of forced cooling, and solidification by the mold wall becomes dominant, and the mold 201 and the alloy Since the contact resistance with the molten metal 255 or the solidified shell is increased, the casting surface is cracked or broken inside the mold, which is not preferable.

  The material of the mold 201 is preferably one or a combination of two or more selected from aluminum, copper, or alloys thereof. A combination of materials can be selected in terms of thermal conductivity, heat resistance, and mechanical strength.

Further, the mold 201 is preferably a mold in which a permeable porous material 222 having a self-lubricating property is loaded in a ring shape on the surface of the mold 201 that contacts the molten alloy 255. The ring shape is a state where the entire inner wall surface 221 of the mold 201 is attached in the circumferential direction. The permeability of the permeable porous material 222 is 0.005 [L / (cm ² × min)] to 0.03 [L / (cm ² × min)] [more preferably 0.007 [L / (cm ² × min)] to 0.02 [L / (cm ² × min)]. It is preferable that The thickness of the permeable porous material 222 to be attached is not particularly limited, but is preferably 2 mm to 10 mm (more preferably 3 mm to 8 mm). As the permeable porous material 222, for example, graphite having an air permeability of 0.008 [L / (cm ² × min)] to 0.012 [L / (cm ² × min)] can be used. Here, the air permeability is obtained by measuring the air flow rate per minute of air having a pressure of 2 (kg / cm ² ) with respect to a test piece having a thickness of 5 mm.

  It is preferable to use the mold 201 in which the permeable porous material 222 is attached to 5 mm to 15 mm of the effective mold length L. It is preferable that the refractory plate-like body 210, the mold 201, and the permeable porous material 222 are disposed on the mating surfaces via an O-ring 213.

  The shape of the inner wall of the cross section in the radial direction of the mold 201 (the inner wall shape when the hollow portion 200 of the mold 201 is viewed from the other end side) is not limited to a circle, but a triangle, a rectangular cross section, a polygon, a semicircle, an ellipse or A shape having an irregular cross-sectional shape having no symmetry axis or symmetry plane may be used. Or when forming a hollow ingot, what hold | maintained the core inside the casting_mold | template may be used. The mold 201 is a cylindrical mold whose both ends are open, and the molten alloy 255 enters the cylindrical interior from one end through the pouring passage 211 formed in the refractory plate-like body 210, The solidified ingot 216 is extruded or pulled out from the other end.

  Further, the vertical cross-sectional shape of the pouring passage 211 may be a semicircle, a pear shape, or a horseshoe shape other than the circular shape.

  The inner wall surface of the mold is formed at an elevation angle of 0 degrees to 3 degrees (more preferably 0 degrees to 1 degree) with the mold center axis 220 toward the drawing direction of the solidified ingot 216. That is, the inner wall surface of the mold is formed in a tapered shape that opens in a cone shape toward the drawing direction. The angle formed by the taper is the elevation angle. If the elevation angle is less than 0 degrees, casting is impossible because the solid ingot 216 is pulled out from the mold 201 and receives resistance at the mold exit. On the other hand, if it exceeds 3 degrees, the inner wall surface of the mold contacts the molten metal column 215. Is insufficient, and the effect of heat removal from the molten alloy 255 or the solidified shell to the mold 201 is reduced, resulting in insufficient solidification. As a result, there is a high possibility that remelted skin will occur on the surface of the ingot or casting trouble such as unsolidified molten alloy 255 may be ejected from the end of the mold.

  The tundish 250 includes a molten metal inflow portion 251 that receives an aluminum alloy melt adjusted to a prescribed alloy component by an external melting furnace or the like, a molten metal holding portion 252, and an outflow portion 253 to the mold 201. The tundish 250 maintains the liquid level 254 of the molten alloy 255 at a position higher than the upper surface of the mold 201, and stably distributes the molten alloy 255 to each cylindrical mold 201 in the case of multiple casting. Is. The molten alloy 255 held by the molten metal holding part 252 in the tundish 250 is poured into the mold 201 from the pouring passage 211 provided in the refractory plate-like body 210.

  Reference numeral 208 denotes a fluid supply pipe for supplying fluid. The fluid can include a lubricating fluid. The fluid may be any one or two or more fluids selected from gas and liquid lubricant. The gas and liquid lubricant supply pipes are preferably provided separately. The fluid pressurized and supplied from the fluid supply pipe 208 is supplied to the gap between the mold 201 and the refractory plate 210 through the annular lubricant supply port 224. It is preferable that a gap of 200 μm or less is formed at a portion where the mold 201 faces the refractory plate-like body 210. The gap is large enough to allow the fluid to flow out to the inner wall surface 221 of the mold 201 so that the molten alloy 255 is not inserted. In the form shown in FIG. 1, the lubricant supply port 224 is formed on the outer peripheral surface side of the permeable porous material 222 attached to the mold 201, and the fluid is permeable porous material by the applied pressure. It is fed to the entire surface of the permeable porous material 222 that penetrates into the interior of 222 and contacts the molten alloy 255, and is supplied to the inner wall surface 221 of the mold 201. The liquid lubricant may be heated to be decomposed gas and supplied to the inner wall surface 221 of the mold 201.

  The corner space 230 is formed by any one or more selected from the supplied gas, the liquid lubricant, and the gas obtained by decomposing the liquid lubricant.

  Next, the refractory plate-like body 210 will be described. FIG. 3 is an explanatory view of a refractory plate-like body according to the present invention. The refractory plate-like body 210 is disposed between the tundish 250 and one end of the mold 201, and is formed of a material having fire resistance and heat insulation. As shown in FIG. 3, the refractory plate-like body 210 includes a heat insulating member 2 (2a, 2c) having a pouring passage 211 for communicating the tundish 250 and the mold 201, and a heat insulating member 2 (2a, 2b) and a partition layer 2c having a through hole integral with the pouring passage 211 provided in a direction substantially perpendicular to or oblique to the pouring passage axial direction. Note that one or more pouring passages 211 may be formed in a portion where the refractory plate-like body 210 faces the hollow portion 200 of the mold 201.

  The refractory plate-like body 210 can be variously configured according to the shape and arrangement of the partition layer 2c. For example, in FIG. 3A having the same configuration as FIG. 1, the first heat insulating member 2a on the tundish 250 side and A partition layer 2c is provided between the second heat insulating member 2b on the mold 201 side. 3B, the through-hole side peripheral portion 20c of the partition layer 2c in FIG. 3A is bent horizontally to form an L shape and face one end of the mold 201. And in FIG.3 (c), it is comprised by the 2nd heat insulation member 2b by the side of the casting_mold | template 201, and the partition layer 2c by the side of the tundish 250, and does not have the 1st heat insulation member 2a.

  The heat insulating member 2 (2a, 2b) is formed of a porous material having low thermal conductivity, such as Nichias Lumiboard, Fosseco Insular, and Ibiden Fiber Blanket Board. The thermal conductivity of these materials is about 0.00033 cal / cm · sec · ° C. On the other hand, the partition layer 2c should just be comprised with the material which does not let the lubricant and the vaporized lubricant pass, such as silicon nitride, silicon carbide, graphite, a metal. Examples of the metal include iron, aluminum, and nickel. The thermal conductivity is preferably about 0.04 to 0.6 cal / cm · sec · ° C.

  In the refractory plate-like body 210 having the above-described configuration, since the partition layer 2c is provided on the heat insulating member 2 (2a, 2b), it is supplied from the permeable porous material 222 to the mold 201 and oozes into the second heat insulating member 2b. The partition layer 2c can prevent the lubricated lubricant from reacting with the molten alloy 255 or wrapping around the tundish 250 side, and can reduce the lubricant by suppressing wasteful consumption of the lubricant. Therefore, high-speed casting can be performed stably and smoothly even if the lubricant is reduced. Moreover, the lubricant reaction product generated on the peripheral wall of the heat insulating member 2 (2a, 2b) or in the vicinity thereof is not generated, and the ingot defects can be greatly reduced.

  Further, since the second heat insulating member 2b is necessarily interposed between one end of the mold 201 and the partition layer 2c, even when the partition layer 2c that facilitates heat transfer is provided, the molten alloy 255 is maintained while maintaining the heat. Can be supplied to the mold 201. Therefore, the solidification position of the molten alloy 255 (columnar molten metal 215) in the mold 201 is properly maintained, and stable casting can be performed.

  Further, since the through-hole side peripheral portion 20c of the partition layer 2c is bent horizontally to be L-shaped so as to face one end of the mold 201, the second heat insulating member between one end of the mold 201 and the partition layer 2c. 2b does not contact the molten alloy 255 even in the portion of the pouring passage 211. Therefore, reaction of the lubricant with the molten alloy 255 via the heat insulating member 2 (2a, 2b) and wraparound to the tundish 250 side can be more reliably prevented.

  The structure of the partition layer 2c only needs to spread in a direction to suppress the seepage of the lubricating oil. For example, the partition layer 2c may have a layer shape, a film shape, a foil shape, or a plate shape.

  The partition layer 2c can be provided by preparing a layered, film-like, foil-like, or plate-like material and contacting or sandwiching the first heat-insulating member 2a or the second heat-insulating member 2b.

  Alternatively, the partition layer 2c can be provided by depositing or spraying a material on the first heat insulating member 2a or the like.

  An intermediate layer may be provided between the partition layer 2c and the first heat insulating member 2a to improve adhesion.

  Moreover, you may make it form a partition layer combining two or more structures of said FIG.3 (a) (b) (c), and it becomes possible to suppress oil bleed still more reliably.

  FIG. 4 is an explanatory diagram of the area of the second heat insulating member. This figure depicts the second heat insulating member 2b and the pouring passage 211 when one end is viewed from the other end of the mold 201. FIG. In the figure, “inner diameter of heat insulating member” and “inner diameter of mold” indicate the diameters of the respective shapes of the heat insulating member and the mold when one end side is viewed from the other end side of the mold 201.

  As described above, the second heat insulating member 2b is configured on one end side of the mold 201. In the first embodiment, as shown in FIGS. 4A and 4B, the second heat insulating member 2b is provided. Among them, the area Sb of the second heat insulating member (second heat insulating member seen when one end side is viewed from the other end side of the mold 201) 20b facing the hollow portion 200 of the mold 201 is defined as a longitudinal section of the hollow portion 200 of the mold 201. The area ratio is 40 to 85% with respect to the area S0. 4A corresponds to FIGS. 3A and 3C, and FIG. 4B corresponds to FIG. 3B.

  Thus, in 1st Embodiment, area Sb of the heat insulation member 20b which faces the hollow part 200 of the casting_mold | template 201 among the 2nd heat insulation members 2b interposed between the end of the casting_mold | template 201 and the partition layer 2c is used as a casting_mold | template. Since the area ratio is 40 to 85% with respect to the longitudinal sectional area S0 of the hollow portion 200 of 201, the second heat insulating member 2b having an area necessary for heat insulation faces the hollow portion 200 of the mold 201 with certainty. For this reason, even if the molten alloy 255 is supplied to the mold 201, the heat of the molten alloy 255 can be prevented from escaping from the one end side of the mold 201 and being cooled. Therefore, the solidification position of the molten alloy 255 (columnar molten metal 215) in the mold 201 is properly maintained, and stable casting can be performed.

  The horizontal continuous casting method of the present invention will be described.

  In FIG. 1, the molten alloy 255 in the tundish 250 is supplied to the mold 201 that is held so that the mold center axis 220 is almost horizontal through the refractory plate-like body 210, and is forcedly cooled at the outlet of the mold 201. Thus, a solidified ingot 216 is obtained. Since the solidified ingot 216 is drawn at a constant speed by a drawing drive device installed near the outlet of the mold 201, it is continuously cast into an aluminum alloy cast bar. The drawn aluminum alloy cast bar is cut into a predetermined length by a synchronous cutting machine.

  The composition of the molten alloy 255 of aluminum alloy stored in the tundish 250 is, for example, Si (content 0.05 to 1.3% by mass), Fe (content 0.10 to 0.70% by mass), Cu ( Content 0.1 to 2.5% by mass), Mn (content 0.05 to 1.1% by mass), Mg (content 0.5 to 3.5% by mass), Cr (content 0.04) -0.4 mass%), and Zn (contents 0.05-8.0 mass% or less). The content of Mg is preferably 0.8 to 3.5% by mass.

  Further, for example, Si (content ratio 0.05 to 1.3 mass%), Fe (content ratio 0.1 to 0.7 mass%), Cu (content ratio 0.1 to 2.5 mass%), Mn ( Content 0.05-1.1 mass%), Mg (content 0.5-3.5 mass%), Cr (content 0.04-0.4 mass%), and Zn (content 0. 05 to 8% by mass or less). The content of Mg is preferably 0.8 to 3.5% by mass.

  The composition ratio of the alloy components of the ingot can be confirmed, for example, by a method using a photoelectric photometric emission spectroscopic analyzer (device example: PDA-5500 manufactured by Shimadzu Corporation, Japan) as described in JIS H 1305.

  The difference between the height of the liquid level 254 of the molten alloy 255 stored in the tundish 250 and the inner wall surface 221 on the upper side of the mold 201 is set to 0 mm to 250 mm (more preferably 50 mm to 170 mm). Is preferred. That is, the castability is stabilized because the pressure of the molten alloy 255 supplied into the mold 201 and the lubricating oil and the gas from which the lubricating oil is vaporized are suitably balanced.

  As the liquid lubricant, vegetable oil which is a lubricating oil can be used. For example, rapeseed oil, castor oil, salad oil can be mentioned. These are preferable because they have little adverse effect on the environment.

  The lubricating oil supply rate is preferably 0.05 mL / min to 5 mL / min (more preferably 0.1 mL / min to 1 mL / min). This is because if the supply amount is too small, a breakout of the solidified ingot 216 occurs due to insufficient lubrication, and if the supply amount is excessive, the surplus is mixed into the solidified ingot 216 and becomes an internal defect.

  The casting speed, which is the speed at which the solidified ingot 216 is drawn from the mold 201, is preferably 200 mm / min to 1500 mm / min (more preferably 400 mm / min to 1000 mm / min). This is because if the casting speed is within this range, the network structure of the crystallized product formed by casting becomes uniform and fine, resistance to deformation of the aluminum material at high temperature increases, and high-temperature mechanical strength improves. .

  The amount of cooling water discharged from the cooling water shower device 205 is preferably 10 L / min to 50 L / min (more preferably 25 L / min to 40 L / min) per mold. If the amount of cooling water is too small, breakout may occur, or the surface of the solidified ingot 216 may be remelted to form a non-uniform structure, which may remain as an internal defect. On the other hand, if the amount of the cooling water is excessive, the heat removal from the mold 201 is too large and casting becomes impossible.

  The average temperature of the molten alloy 255 flowing into the mold 201 from the tundish 250 is preferably 600 ° C. to 750 ° C. (more preferably 650 ° C. to 700 ° C.). If the temperature of the molten alloy 255 is too low, a coarse crystallized product is formed in the mold 201 and before and is taken as an internal defect inside the solidified ingot 216. On the other hand, if the temperature of the molten alloy 255 is too high, a large amount of hydrogen gas is taken into the molten alloy 255 and taken into the solidified ingot 216 as porosity, resulting in internal defects.

  Next, an example of the second embodiment of the present invention will be described with reference to FIGS.

  FIG. 5 is a view showing an example of the vicinity of the mold of the horizontal continuous casting apparatus in the second embodiment, and FIG. 6 is a view showing a configuration of a lubricant supply portion in the second embodiment. The second embodiment differs from the first embodiment in the configuration of the lubricant supply portion. In addition, the refractory plate-like body 210 is not provided with a partition layer, and is composed only of a heat insulating member made of a lumi board or the like.

  In the second embodiment, as shown in FIGS. 5 and 6A, the lubricant supply port 224 a provided on the inner peripheral wall of the mold near one end of the mold 201 is extended to the other end of the mold 201. The length is, for example, 2 to 13 mm (preferably 2 to 7 mm) in the horizontal direction.

  Thus, since the lubricant supply port 224a is expanded to the other end of the mold 201, the lubricant can be supplied also from the other end of the mold 201. In the case of high-speed casting, the solidification position of the columnar metal melt 215 tends to move to the other end side of the mold, and in order to supply the lubricant to the other end side, conventionally, a larger amount of lubrication is required near one end of the mold 201 than necessary. Although the material has been supplied (see the lubricant supply port 224a in FIG. 1), the expanded lubricant supply port 224a can accurately supply the lubricant near the other end. That is, since an appropriate amount of the lubricant is supplied to the necessary portions, unnecessary lubricant is not supplied, and high-speed casting can be performed stably and smoothly even if the lubricant is reduced.

  Further, as shown in FIG. 6B, the lubricant supply port 224b may be branched and provided near the other end of the mold. The branch width of the lubricant supply port 224b is, for example, 2 to 13 mm (preferably 2 to 7 mm) in the horizontal direction as in the case of the expansion. As described above, the branched lubricant supply port 224b allows the lubricant to be supplied from the other end of the mold 201 as in the case of the expanded lubricant supply port 224a. In other words, even in the case of high-speed casting, an appropriate amount of lubricant is supplied to the necessary portions, so that unnecessary lubricant is not supplied, and high-speed casting is performed stably and smoothly even if the lubricant is reduced. be able to.

  Next, an example of the third embodiment of the present invention will be described with reference to FIG.

  FIG. 7 is an explanatory view showing the position of the pouring passage in the third embodiment. The third embodiment is different from the first embodiment in that the position of the pouring passage (molten supply port) 211 is defined. In addition, the refractory plate-like body 210 is not provided with a partition layer, and is composed only of a heat insulating member made of a lumi board or the like.

  As shown in FIG. 7, in the third embodiment, the pouring passage 211 and the mold 201 are in a positional relationship such that the pouring passage inner diameter lower position P1 is smaller than the mold inner diameter lower position P0. The height h is 8% or more (preferably 10% or more) above d.

  The upper limit of the height h of the pouring passage inner diameter lower position P1 is not particularly limited, but the upper limit is that the heat balance above and below the mold is broken and no ingot solidification shell is formed, or the pouring passage (pouring port) The upper limit is the point where the center position of the cross-sectional shape is not higher than the center position of the mold hollow section, or the upper limit is the point where the shape is positionally determined. For example, it can be 30% or less (preferably 25% or less) of the mold inner diameter d with respect to the mold inner diameter lower position P0.

In this way, by defining the height h of the pouring passage 211, the pouring passage 211 is simply positioned on the lower side of the inner diameter of the mold in order to make the temperature balance of the conventional ingot uniform. Compared to
Since the lower limit of the position of the pouring passage has a certain height, the molten metal flows in from that height, and the heat is extracted before reaching the lower portion of the mold. In other words, the conventional position determination method does not consider the heat removal from the pouring spout until it reaches the lower surface of the mold, and therefore it is necessary to readjust the lubricating oil amount due to changes in casting diameter, molten metal temperature, etc. In addition, it was difficult to change the conditions for stabilizing the operation.

  On the other hand, in the present invention, by defining the height h of the pouring passage 211, the temperature of the molten alloy supplied to the lower end on the one end side of the mold 201 is lowered, and the formation of the solidified shell at the lower part of the ingot is promptly performed. As a result, stable casting can be performed even if the supply amount of the lubricant is reduced. Therefore, high-speed casting can be performed stably and smoothly even if the lubricant is reduced. In addition, since the temperature of the molten alloy supplied to the lower part at one end of the mold is lowered, the gasification of the lubricant can be suppressed and the occurrence of ingot defects due to the gasified lubricant being caught in the ingot is prevented. can do.

  In this way, even if the casting diameter, molten metal temperature, etc. change and the amount of lubricating oil needs to be readjusted, the amount of lubricating oil (lubricant) is reduced, so that the operation can be stabilized. The control range can be small, so the condition can be easily changed.

  As described above, according to the first, second, and third embodiments of the present invention, stable horizontal continuous casting can be performed in any case even if the supply amount of lubricant is reduced. Even if the lubricant is reduced, high speed casting becomes possible. By the way, also in the case of casting of an aluminum alloy containing magnesium, it seems that it is due to the presence of magnesium having a large activity, but stable casting is difficult unless the amount of lubricant is increased. The present invention reduces the amount of lubricant, the reaction product of the lubricant even in the casting of an aluminum alloy containing a large amount of such magnesium, for example, 0.5% by mass or more (preferably 0.8% by mass or more). The same effects as those exhibited in the case of high-speed casting, such as suppression of occurrence, stable smooth casting, and prevention of ingot defects, can be exhibited.

  In the above description, each of the first, second, and third embodiments is implemented independently. However, the overall configuration of the embodiment and the main configuration in the embodiment may be arbitrarily combined. . Arbitrary combinations, for example, the third embodiment and the first embodiment are combined around the third embodiment, or the third embodiment and the second embodiment are combined. By such a combination, various effects such as reduction of the lubricant can be exhibited more remarkably.

  (Examples 201 to 216) Examples 201 to 216 and Comparative Examples 201 and 202 were carried out in order to confirm the effect of the position regulation of the pouring passage (molten supply port). That is, in the high-speed casting, it was confirmed by the following test that the tensile damage and breakout generated by the formation of the solidified shell from the lower part of the mold in the mold can be suppressed by changing the lower limit position of the pouring passage.

  Here, the casting rod diameter, casting speed, partition layer, pouring passage diameter, pouring passage position is changed, the minimum amount of lubricating oil that causes dragging, and oil penetration at that time The percentage was evaluated.

  A 6061 alloy is used as the aluminum alloy, and the alloy composition is Si: 0.6%, Fe: 0.2%, Cu: 0.3%, Mn: 0.05%, Cr: 0.05%, Ti: 0 The components of the molten metal were adjusted to 1% and Mg: 0.8%. The casting rod diameter was two, 30 mm and 60 mm.

  As the lubricant supply port, the extended lubricant supply port shown in FIG. 6A was used, and the extended horizontal length was set to 4 mm.

  As the partition layer, FIG. 3A is used, the material is silicon nitride, and the thickness is 1 mm. The thickness of the second heat insulating member in contact with the mold (mold) was 1 mm.

  As the cross-sectional shape of the pouring passage, a round hole was adopted in Examples 201 to 213, and a lower semicircular shape was adopted in Examples 214 to 216. The area ratio of the second heat insulating member facing the hollow member of the molds of Examples 201 to 206 was 75%. The position of the pouring passage was evaluated based on the ratio between the lower portion of the pouring passage inner diameter communicating with the tundish and the mold and the inner diameter of the casting mold so as not to depend on the casting rod diameter.

  The casting temperature (undish melt temperature) was 700 ° C., and the casting speed was 700 to 1200 mm / min.

  The minimum amount of lubricating oil that becomes the limit at which tensile scratches occur was measured by observing the casting surface during casting and the amount of lubricating oil at which tensile scratches began to occur.

  The occurrence of oil bleeding was indicated by the ratio of the area of the carbonized part by observing the cross section in the casting direction of the refractory (second heat insulating member) after the experiment.

The results of Examples 201 to 216 and Comparative Examples 201 and 202 performed under the above various conditions are shown in Table 1 below.

  In the high-speed casting, as in Comparative Examples 201 and 202, a breakout occurred when the ratio of the inner diameter lower position of the pouring passage for communicating the tundish and the mold to the mold inner diameter was 5%. It has been found that the amount of lubricating oil that causes scratches decreases with an increase from 8%. That is, it was found that high-speed casting is possible even when the lubricating oil supply amount is suppressed to 0.2 g / min or less.

It is a principal part schematic sectional drawing which shows an example of the mold vicinity of the horizontal continuous casting apparatus of this invention. It is explanatory drawing of the effective mold length of the casting_mold | template of FIG. It is explanatory drawing of the refractory plate-shaped object which concerns on this invention. It is explanatory drawing of the area of a 2nd heat insulation member. It is a figure which shows an example near the casting_mold | template of the horizontal continuous casting apparatus in 2nd Embodiment. It is a figure which shows the structure of the lubricant supply part in 2nd Embodiment. It is explanatory drawing which shows the position of the channel | path for pouring in 3rd Embodiment.

Explanation of symbols

2 Heat Insulating Member 2a Heat Insulating Member 2b Heat Insulating Member 2c Partition Layer 20b Heat Insulating Member 20c Perforation Side Periphery 200 of Partition Layer Mold Hollow Part 201 Cylindrical Mold (Mold)
202 Cooling water 203 Cooling water supply pipe 204 Mold cooling water cavity 205 Cooling water shower device 208 Fluid supply pipe 210 Refractory plate-like body 211 Pouring passage 213 O-ring 215 Columnar molten metal 216 Solid ingot 220 Mold central axis 221 Mold inner wall 222 Permeable porous material 224 Lubricant supply port 224a Lubricant supply port 224b Lubricant supply port 230 Corner space 250 Tundish 251 Molten inflow portion 252 Melt holding portion 253 Outflow portion 254 Liquid surface level 255 Alloy molten metal L Effective mold length P0 Mold inner diameter lower position P1 Pouring passage inner diameter lower position S0 Mold vertical cross-sectional area Sb Area of second heat insulating member d Mold inner diameter h Height of pouring passage inner diameter lower position relative to mold inner diameter lower position

Claims (13)

In a horizontal continuous casting apparatus for producing an aluminum alloy casting rod by supplying molten alloy in a tundish into one mold from one end of a mold arranged horizontally.
The pouring passage formed between the tundish and one end of the mold is formed in a heat insulating member, and communicates the tundish and the mold. 8% or more above the inner diameter of the mold relative to the lower position of the inner diameter of the mold,
Lubricating oil supply amount from the annular lubricant supply port provided on the inner peripheral wall of the mold is 0.24 g / min or less,
The pouring passage includes a lower semicircular shape in its outline,
A horizontal continuous casting apparatus characterized by that. A heat insulating member disposed between the tundish and one end of the mold and having a pouring passage for communicating the tundish and the mold;
The horizontal continuous casting apparatus according to claim 1, further comprising: a partition layer provided in the heat insulating member in a substantially vertical direction and having a passage hole integral with a pouring passage.   The horizontal continuous casting apparatus according to claim 2, wherein a heat insulating member is interposed between one end of the mold and the partition layer.   The horizontal continuous casting apparatus according to claim 2, wherein the partition layer has a through hole side peripheral portion bent horizontally and facing one end of the mold.   Of the heat insulating member interposed between one end of the mold and the partition layer, the area of the heat insulating member facing the hollow part of the mold is 40 to 85% in terms of the area ratio with respect to the longitudinal sectional area of the hollow part of the mold, The horizontal continuous casting apparatus according to claim 3 or 4.   The horizontal continuous casting apparatus according to any one of claims 2 to 5, wherein the partition layer is made of a material that does not pass a lubricant and a vaporized lubricant.   The horizontal continuous casting apparatus according to claim 1, wherein a lubricant supply port provided on a mold inner peripheral wall near one end of the mold is extended to a position near the other end of the mold. The horizontal continuous casting apparatus according to any one of claims 1 to 7, wherein the molten aluminum alloy has a magnesium content of 0.5 mass% or more . The components of the molten aluminum alloy are Si (content 0.05 to 1.3% by mass), Fe (content 0.1 to 0.7% by mass), Cu (content 0.1 to 2%). 5 mass%), Mn (content ratio 0.05 to 1.1 mass%), Mg (content ratio 0.8 to 3.5 mass%), Cr (content ratio 0.04 to 0.4 mass%), And the horizontal continuous casting apparatus in any one of Claim 1 to 7 which shall contain Zn (content rate 0.05-8.0 mass% or less) . In the horizontal continuous casting method for producing an aluminum alloy casting rod by supplying molten alloy in the tundish from one end of the mold arranged horizontally to the mold,
Formed in a heat insulating member disposed between the tundish and one end of the mold, the pouring passage communicating the tundish and the mold and the positional relationship between the casting mold, the pouring passage inner diameter lower position, It should be 8% or more above the inner diameter of the mold relative to the lower position of the inner diameter of the mold so that the solidified shell is formed from the lower part of the ingot in the mold,
Lubricating oil supply amount from the annular lubricant supply port provided on the inner peripheral wall of the mold is 0.24 g / min or less,
The pouring passage is assumed to include a lower semicircular shape in its outline,
A horizontal continuous casting method characterized by the above. A partition layer having a through hole integral with the pouring passage is provided in the heat insulating member having a pouring passage arranged between the tundish and one end of the casting mold and communicating the tundish and the casting mold, The horizontal continuous casting method according to claim 10, wherein horizontal continuous casting is performed while the lubricant that is supplied to the mold during casting and exudes to the heat insulating member is blocked by a partition layer . The lubricant supply port provided in the inner peripheral wall of the mold near one end of the mold is expanded to the other end of the mold, and the lubricant is also supplied to the other end of the mold during horizontal continuous casting. The horizontal continuous casting method as described. An aluminum alloy casting rod produced by using the horizontal continuous casting method according to any one of claims 10 to 12.

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