JPH04125046U - Horizontal continuous casting equipment for strip metal ingots - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to continuously obtain a metal ingot with a unidirectional solidified structure extending in the casting direction without breaking out even if the drawing speed is increased, and the heating mold Prevents the molten metal inside from oxidizing. [Structure] A cooling spray 11 is located above the upper opening of the heating mold 5, and is provided in front of the solidification start tip of the metal molded body 10 in the direction of movement of the metal molded body and behind the exit of the heating mold. , the upper surface of the heating mold 5 from the side wall 3 side of the molten metal holding furnace 1 to the cooling spray 11 is shielded by a shielding member 12 to be isolated from the outside air, and the back surface of the shielding member 12 and the upper surface of the molten metal 2 facing this back surface are An inert gas is filled in the gap.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a device for continuously casting metal ingots, and to be more specific, A complete mold that extends in the casting direction using a flat, trough-shaped heated mold. This article relates to a horizontal continuous casting device that continuously casts a band-shaped metal ingot with a directionally solidified structure. It is something to do.

0002

[Conventional technology]

Conventional horizontal continuous casting equipment for ingots uses a hollow cooling mold that is placed horizontally. , molten metal is supplied from one end of the mold, solidified in the mold, and the ingot is continuously poured from the other end. Casting of iron alloys, aluminum alloys, copper alloys, etc. has been widely used. However, when using a cooling mold, the The molten metal forms a solidified shell along the mold wall, and the unsolidified metal inside is surrounded by this solidified shell. In order for the molten metal to completely solidify through secondary cooling outside the mold, the final The solidification part has the disadvantage that impurities are concentrated and defects such as component segregation and bubbles occur. existed.

0003 In addition, with such conventional equipment, friction between the mold and the surface of the ingot when pulling out the ingot is To prevent the occurrence of surface cracks and breakout of the molten metal, the Intermittent drawing has been carried out in which the stable solidified shell of the ingot is grown and then pulled out. However, the oscillation marks formed on the ingot surface due to this are caused by the plasticity of the ingot. This can cause cracks to occur during processing, so it is necessary to remove such surface defects from the ingot during casting. In order to achieve this, the ingot requires surface care such as removing scratches, facing, and melting before plastic working. It was important.

0004 In addition, for alloys with a wide solidification temperature range such as cast iron and phosphor bronze, If the molten metal is not pulled out of the mold intermittently after it has completely solidified, surface cracks will occur. It was not possible to pull out the ingot without cracking.

[0005] In this way, conventional horizontal continuous casting equipment forms a solidified shell on the inner wall surface of the cooling mold. In order to There was a tendency to When columnar crystal bands are formed on the surface layer of the ingot, it becomes difficult to pull out the ingot from the mold. Furthermore, cracks are likely to occur at grain boundaries due to friction with the inner wall surface of the mold, and Ingots with columnar crystal bands on the outer periphery are prone to surface cracks during plastic working, and are particularly For metals and alloys with poor workability, even if an ingot is made by continuous casting, it is further plasticized. It has been considered difficult to process it into plates or wires.

[0006] The inventor of this invention is the Special Publication No. 55-46265 published on November 21, 1980. In this method, the formation of a surface solidified shell on the inner wall surface of the mold as described above is prevented, and the It consists of a completely unidirectional solidified structure in which crystals grow only in the casting direction, and the ingot and mold It prevents the occurrence of surface defects caused by friction with the We proposed a new continuous casting method for the purpose of obtaining metal molded bodies, and received Japanese Patent No. 1049146. It was patented as No. This new continuous casting method reduces the temperature of the inner wall surface of the hollow mold outlet. By heating with a heating element built into the hollow mold, the temperature exceeds the solidification temperature of the cast metal. The molten metal supplied from the molten metal holding furnace does not form a solidified shell on the inner wall surface of the mold. The solidification of the unsolidified molten metal on the surface of the ingot starts outside the outlet of the mold and stretches in the casting direction. This method continuously casts a metal ingot with a unidirectional solidification structure.

[0007] However, if this new continuous casting method is applied to the horizontal continuous casting method described above, In this case, the solidification of the ingot takes place near the exit of the mold, so the internal temperature of the mold and the cooling water Subtle changes in temperature and casting speed can cause breakout of the molten metal at the mold exit end. To prevent this, the position and shape of the solidification interface within the mold must be constantly adjusted. It is extremely important to accurately understand the

[0008] Therefore, the inventor of this invention proposed US Patent Nos. 4 and 6, which was granted on August 12, 1986. In No. 05,056, the position of the solidification interface is determined by opening the upper part of the heating mold. We have proposed a horizontal continuous casting machine for metal moldings that allows for accurate determination of metal moldings. child ’s horizontal continuous casting equipment has a concave cross section with an open top instead of a hollow heating mold. A heating mold is installed horizontally on the side wall of the molten metal holding furnace just below the molten metal surface, and the molten metal is poured into it. After touching the tip of the metal molded object dummy set in advance in the mold, place the dummy into the mold. By pulling it out and passing it through the cooling means provided outside the mold, the dummy and and the subsequent metal molded body. The inner wall surface of the mold with the heating element If the temperature is kept above the solidification temperature of the cast metal, the metal molded body in the mold will Solidification does not start on the inner wall surface, but only at the tip of the metal compact or dummy. Hardening progresses preferentially, and by pulling the dummy out of the mold, metal forming follows the dummy. The shape can be pulled out, which makes the outer surface smooth and free of cavities in the casting direction. A metal ingot having an elongated unidirectional solidification structure can be continuously obtained.

[0009]

[Problem that the idea aims to solve]

However, the metal molded body in the heated mold solidifies on the inner wall surface of the mold. Prioritizes solidification only at the tip of the metal molded object or dummy without starting solidification. In order to If the heating time is too fast, the metal molded body will not adhere to the dummy, or the molten metal will not come out of the heated mold. It turns out that it can be washed away from the mouth.

0010 Therefore, the purpose of this invention was to increase the speed of drawing out the metal molded body from the heated mold. , a metal with a unidirectional solidification structure that extends in the casting direction without breakout. Ingots can be obtained continuously and the molten metal in the heating mold is prevented from oxidizing. It is an object of the present invention to provide a horizontal continuous casting device for a band-shaped metal ingot, which is capable of stopping.

[0011]

[Means to solve the problem]

This device has an open upper part that is roughly gutter-shaped, and uses heating means to heat the metal to a temperature higher than the solidification temperature of the cast metal. A heating mold heated to A dummy member that pulls out a metal molded body formed from molten metal, and a dummy member that cools this metal molded body. In horizontal continuous casting equipment for strip metal ingots, the equipment has a cooling means for cooling. The means is positioned over the upper opening of the heating mold and the solidification point of the metal molded body is started. Provided at the front of the end in the direction of movement of the metal molded body and at the rear of the exit of the heating mold. , the upper surface of the heating mold from the side wall of the molten metal holding furnace to the cooling means is isolated from the outside air. A shielding member is provided, and the back surface of this shielding member and the molten metal facing the back surface are The feature is that an inert gas is filled in the gap between the top surface and the top surface.

0012

[Effect]

According to this configuration, the solidification of the molten metal occurs on the inner wall of the heated mold, which is maintained at a temperature higher than its solidification temperature. Solidification starts only from the part where the molten metal contacts the dummy member, avoiding the surface. then By pulling out the dummy member, the rear end of the dummy member can be The metal molded body formed sequentially from the attached part is cooled, so the exit of the heated mold On the side, a strip-shaped metal molded body is obtained which exhibits the desired solidified cross-sectional shape. Also, water vapor is generated when the molten metal is cooled, and this water vapor can cause the molten metal to oxidize. However, inert gas may be present in the gap between the top surface of the molten metal in the heating mold and the bottom surface of the shielding member. Since the top surface of the molten metal is covered with a kind of air curtain, Can be maintained in an inert or reducing atmosphere. Furthermore, in the heated mold Since it is cooled and solidified to completion, the metal molded body can be pulled out at a fast speed. The metal compact can be drawn continuously at high speed without breaking out with the molten metal. I can put it out. The strip-shaped ingot of metal or alloy obtained in this way has surface cracks. A perfect cast iron that extends in the casting direction with no risk of center segregation or cavities, and has excellent workability. It can have a unidirectional solidification structure.

[0013]

【Example】

Hereinafter, one embodiment of this invention shown in the drawings will be explained. contains the molten metal 2 to be cast, and the surface of the molten metal 2 is controlled by a general method ( (not shown) to keep it as constant as possible. Molten metal holding furnace 1 An opening 4 is formed in the side wall 3, and a heating mold 5 for molding is inserted into this opening 4. is installed so that its inlet side communicates with the inside of the molten metal holding furnace 1. Heating mold 5 is approximately horizontal to the side wall 3 of the molten metal holding furnace 1, preferably as shown in the figure. Install so that the outlet side of mold 5 is slightly inclined downward by 2 to 5 degrees with respect to the inlet side. The cross section is concave and has a generally gutter-like shape with an open top. this The heating mold 5 also has a bottom wall 7 below the level of the molten metal 2 to obtain the desired thickness. It is attached to the side wall 3 of the molten metal holding furnace 1 so as to be located at the same position. Both side walls of heating mold 5 6 and the bottom wall 7 are provided with a heating element 8, and the heat of the heating element 8 causes the molten metal 2 to be heated. The inner wall surface of the heating mold 5 in contact with the mold is heated to a temperature higher than the solidification temperature of the cast metal. heating element 8 consists of an electric resistance heating element whose temperature changes depending on the supplied current; The temperature of the inner wall of the thermal mold 5 is adjusted by this heating element 8. 9 is a metal molded body dummy -, so that it can be inserted into the heating mold 5 from the exit side of the heating mold 5 so as to be able to move forward and backward. ing.

[0014] Above the opening of the heating mold 5, there is a hole in contact with the rear end of the metal molded body dummy 9 in the drawing direction. A cooling spray 1 which is a cooling means for cooling the metal molded body 10 that has been touched and pulled out. 1 is located. This cooling spray 11 sprays cooling water onto the metal molded body 10. It should be taken out and cooled. The cooling spray 11 covers almost the entire width of the metal molded body 10. is arranged to inject cooling water over the heating mold 5 and the cooling water is heated at the outlet of the mold 5 The molten metal 2 is arranged so that water is not splashed on the molten metal 2 by injecting it in the direction. heating casting The upper surface between the side wall 3 side of the molten metal holding furnace 1 of the mold 5 and the cooling spray 11 is a shielding member. 12, and the upper surface of the molten metal holding furnace 1 is also shielded from the outside air by a lid 13. ing. The lid 13 has a space between the upper surface of the molten metal 2 in the molten metal holding furnace 1 and the lower surface of the lid 13. A gas supply pipe 14 for supplying an inert gas such as argon gas to the gap is installed. It is attached. The inert gas supplied from the gas supply pipe 14 is passed through the opening 4. The cooling spray passes through the gap between the upper surface of the molten metal 2 in the heating mold 5 and the lower surface of the shielding member 12. - released from 11 parts. This inert gas is applied to the upper surface of the molten metal 2 in the heating mold 5. Spraying, water vapor and splashes generated when the metal molded body 10 is cooled by the cooling spray 11. This prevents the molten metal 2 from being oxidized by the sprinkled water.

[0015] Next, the production of a band-shaped metal ingot using the casting apparatus configured as described above will be explained. First, the temperature of the inner wall of the heating mold 5 in contact with the molten metal 2 is controlled by controlling the current supplied to the heating element 8. and adjust the temperature to above the solidification temperature of the metal to be cast. This temperature is also the heating mold 5 Considering that the front half is cooled by cooling water when viewed from the pull-out direction, It is necessary to set the temperature considerably higher than the solidification temperature of the genus. In this state, the metal molded body Insert the dummy 9 from the outlet end of the heating mold 5 in the opening 4 directions and hold the molten metal. A molten metal 2 is supplied from a furnace 1 to a heating mold 5. Heating mold at the rear end of metal molded body dummy 9 The molten metal 2 is brought into contact with the molten metal 2 flowing in from the inlet 5. When inserting the metal molded body dummy 9, The upper surface of the molten metal 2 is cooled by the cooling spray 11, so that the molten metal 2 reaches a temperature higher than the solidification temperature. It came into contact with the cooled metal molded body dummy 9 while avoiding the inner wall surface of the heated mold 5 that was maintained. Coagulation starts from that part. Next, pull the metal molded body dummy 9 to the right in the drawing. By drawing out the metal molded body dummy 9, it is formed sequentially from the part attached to the rear end. The metal molded body 10 is located below the cooling spray 11, where it is cooled and solidified. A band-shaped metal molded body 10 having a desired cross-sectional shape is obtained. cooling spray 1 When cooling molten metal 2 with cooling water from 1, water vapor is generated, and this water vapor causes molten metal 2 may oxidize, especially copper, silicon or stainless steel. It is necessary to prevent oxidation in cases where the Then, the inert gas from the gas supply pipe 14 flows through the opening 4 into the molten metal in the heating mold 5. The cooling spray 11 is released through the gap between the upper surface of 2 and the lower surface of the shielding member 12. The upper surface of the molten metal is covered with a kind of air curtain. Therefore, it can be maintained in an inert atmosphere.

[0016] In this way, it is cooled in the heating mold 5 to complete solidification. Therefore, even if the metal molded body 10 is pulled out at a high speed, breakout with the molten metal 2 will not occur. The metal molded body 10 can be continuously pulled out without being pulled out. Furthermore, as mentioned above By tilting the heating mold 5 and the drawing direction downward, the cooling spray 1 The cooling water from 1 does not flow to the molten metal 2 side, but can flow naturally to the outlet side. Not only that, but the molten metal 2 can be continuously flowed into the heating mold 5. To reliably prevent the occurrence of cuts, etc. due to drawing out between the molten metal 2 and the metal molded body 10. I can do that.

[0017] The thickness of the metal molded body 10 is determined by the thickness of the molten metal holding furnace 1 relative to the level of the bottom wall 7 of the heating mold 5. It can be set by adjusting the level of the molten metal 2 inside. In this case, the molten metal 2 The gap between the upper surface and the lower surface of the shielding member 12 is narrowed to reduce contact with water vapor. In both cases, it is desirable to increase the flow rate of the inert gas to strengthen the air curtain effect. stomach. Note that the width of the metal molded body 10 is determined by the width of the opening 4 of the side wall 3 of the molten metal holding furnace 1 and It can be set by adjusting the width between the side walls 6 of the heating mold 5.

[0018] The heating mold 5 is made of graphite for alloys with low solidification temperatures, such as aluminum and copper alloys. For steel, cast iron, or high melting point alloys, alumina, silica, and berlin are used. rear, magnesia, toriya, zirconia, boronite, silicon carbide, silicon Molds made of refractory materials such as recon nitride may be used, but please be careful when choosing. Therefore, it is necessary to choose a material that will react with the molten metal and will not be corroded.

[0019] In the above embodiment, in order to supply inert gas to the lid 13 of the molten metal holding furnace 1, However, as shown by the two-dot chain line in Fig. 1, the hot casting A gas supply pipe 15 may be provided on the shielding member 12 of the mold 5. Also, metals such as copper If so, use a reducing gas such as carbon monoxide gas instead of an inert gas, and create a reducing atmosphere. May be retained.

[0020]

[Effect of the idea]

As described above, the horizontal continuous casting device for band-shaped metal ingots of this invention is equipped with cooling means. The metal mold is placed over the upper opening of the mold, and the metal molded body is heated from the tip where it begins to solidify. Provided in front of the direction of movement of the molded body and behind the outlet of the heating mold. Therefore, when solidifying the molten metal, avoid the inner wall surface of the heating mold that is kept above the solidification temperature. Solidification starts only from the part where the dummy member comes into contact with the dummy member, and the dummy member cannot be pulled out. By doing this, the shape is shaped sequentially starting from the part attached to the rear end when viewed from the direction in which the dummy member is pulled out. The formed metal compact is cooled, and the desired solidified section is formed at the exit side of the heating mold. A band-shaped metal molded body exhibiting a planar shape can be obtained. In this way, inside the heated mold Since the metal molded body is cooled and solidified at a high speed, Continuously forms metal at high speed without causing breakout with the molten metal even when pulled out Processing that allows the body to be pulled out, without the risk of surface cracks, and without center segregation or cavities. Creates a band-shaped metal ingot with a perfect unidirectional solidification structure extending in the casting direction with excellent properties. can be done.

[0021] Furthermore, the top surface of the heating mold from the side wall of the molten metal holding furnace to the cooling means is shielded from outside air. A shielding member is provided for Inert gas is placed in the gap between the top surface of the molten metal and the top surface of the molten metal. The molten metal will be covered with an air curtain, and water vapor will be generated when the molten metal is cooled. It is possible to reliably prevent molten metal from being oxidized by steam, so oxidation prevention is effective. Suitable for casting metals such as copper, silicon or stainless steel as required It is.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view schematically showing the main parts of an embodiment of a horizontal continuous casting apparatus for band-shaped metal ingots according to the present invention.

FIG. 2 is a perspective view showing the heating mold portion.

[Explanation of symbols]

1 Molten metal holding furnace 2 Molten metal 3 Side wall 4 Opening 5 Heating mold 8 Heating element 9 Metal molded body dummy 10 Metal molded body 11 Cooling spray 12 Shielding member 13 Lid body 14,15 Gas supply pipe

Claims (1)

[Scope of utility model registration request] 1. A molten metal holding furnace, a heating mold having one end communicating with the side wall of the molten metal holding furnace, having a substantially gutter-like shape with an open upper part, and heated to a temperature equal to or higher than the solidification temperature of the cast metal by heating means; Horizontal continuous casting of a band-shaped metal ingot, which has a dummy member for drawing out a metal molded body formed from the molten cast metal supplied to the heating mold, and a cooling means for cooling the metal molded body. In the apparatus, the cooling means is located above the upper opening of the heating mold, and is located in front of the solidification start tip of the metal molded body with respect to the movement direction of the metal molded body and behind the outlet of the heating mold. A shielding member is provided to isolate the upper surface of the heating mold from the side wall side of the molten metal holding furnace to the cooling means from outside air, and the back surface of the shielding member and the molten metal facing the back surface An apparatus for horizontal continuous casting of band-shaped metal ingots, characterized in that an inert gas is introduced into the gap between the top surface and the top surface of the metal ingot.