A continuous casting apparatus for superalloy tubes

Abstract

The application belongs to the technical field of metal material preparation, and discloses a continuous casting equipment for high-temperature alloy pipe. The equipment comprises a supporting base, a crucible, an induction heating device, a core material, a graphite heating and heat preservation device, a graphite cooling jacket, a drawing device, a secondary water cooling device, a casting mold and a thermocouple temperature measuring device. The equipment is based on a downward drawing type high-temperature alloy continuous casting technology, adopts a core material made of boron nitride ceramic material which is resistant to high-temperature alloy melt erosion and has low thermal conductivity and a graphite heating and cooling device, and realizes direct continuous manufacturing of the high-temperature alloy pipe. The equipment develops an equipment structure which can prevent the high-temperature alloy dummy bar head from being easily broken before continuous casting, and the reaction of the high-temperature alloy melt and the graphite casting mold or the surface oxidation, so as to solve the problems of low stability and poor surface quality of the high-temperature alloy continuous casting. The equipment has very important significance for accelerating the development and application of the high-temperature alloy pipe.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal material preparation, and in particular, a continuous casting equipment for high-temperature alloy pipe is designed. BACKGROUND

[0002] High-temperature alloy pipe has a broad application prospect in the fields of petroleum chemical industry, energy, metallurgy and power due to its excellent high-temperature resistance, corrosion resistance, oxidation resistance and other properties. High-temperature alloy pipe needs to serve safely for a long time in harsh environments, which puts forward higher requirements for high-temperature alloy pipe (such as nickel-based and iron-based). However, the current high-temperature alloy has the characteristics of high alloying degree, serious segregation, large deformation resistance, difficult organization control, low product performance and long production process, which makes it a big problem to produce high-temperature alloy pipe with excellent quality.

[0003] At present, the traditional high-temperature alloy seamless pipe mainly adopts the methods of "centrifugal casting pipe blank-welding splicing-multi-pass cold rolling-annealing", "melting-homogenization annealing-forging breaking down-hot extrusion-multi-pass cold rolling-intermediate annealing" and "melting-homogenization annealing-casting ingot breaking down-perforation-spinning-annealing". However, the above traditional methods have the following problems: (1) the method of centrifugal casting pipe-welding to prepare pipe blank will cause uneven composition distribution, and the performance of the pipe cannot be guaranteed, which cannot directly produce longer high-temperature alloy pipe profiles; (2) high-temperature alloy cold forming is difficult, and the hot extrusion process parameters are difficult to control; (3) the pipe blank for hot perforation is prone to cracks or even breakage, and it is difficult to ensure coaxiality when mechanical drilling is used for long blanks, which not only makes the perforation quality uneven, but also has low production efficiency. Moreover, most of the equipment for producing pipe is not an integrated continuous casting equipment. The inner sleeve material of the current hollow pipe continuous casting equipment is still graphite, which is easy to react with iron and other metal elements, not only damaging the graphite crystallizer, but also affecting the castings themselves. Therefore, such equipment is difficult to meet the demand of high-temperature alloy continuous casting, and cannot be applied to the continuous casting of high-temperature alloy pipe. The above problems of traditional equipment have become a bottleneck problem restricting the production of high-performance high-temperature alloy pipe, and need to be improved.

[0004] In summary, in view of the problems existing in the prior art and equipment, an equipment structure and method are developed to prevent the high-temperature alloy starter rod head from being easily broken before continuous casting, and the reaction of high-temperature alloy melt with graphite mold or surface oxidation, which solves the problems of low stability and poor surface quality of high-temperature alloy continuous casting. It has very important significance for speeding up the development and application of high-temperature alloy pipe. SUMMARY

[0005] To solve the above problems, the application discloses a continuous casting equipment for high-temperature alloy pipes, which comprises a crucible, an induction heating device, a graphite heating and heat preservation device, a flow guide channel, a core material, a casting mold, a thermocouple temperature measuring device, a drawing device, a graphite cooling jacket, a support base and a secondary water cooling device.

[0006] As a further design of the present scheme, the crucible is made of a material that does not react with alloy elements in the high-temperature alloy melt, such as boron nitride, zirconium oxide and silicon carbide, so that the melting point of the crucible material is higher than the melting point of the high-temperature alloy by 300 degrees Celsius, thereby ensuring the production of high-quality high-temperature alloy pipes.

[0007] As a further design of the present scheme, the induction heating device comprises a first induction heating device and a second induction heating device, which are respectively located outside the graphite heating and heat preservation device above the large crucible, the small crucible and the casting mold, and are used for metal melting and heat preservation.

[0008] As a further design of the present scheme, the graphite heating and heat preservation device comprises graphite heating bodies and graphite heating bodies b, which are made of graphite and have the advantages of uniform heating structure, good electrical conductivity, high electrical load, strong corrosion resistance and oxidation resistance, high energy saving and efficiency, etc.

[0009] As a further design of the scheme, the core material is made of boron nitride ceramic material with high temperature resistance, high temperature alloy melt corrosion resistance and low thermal conductivity, which can avoid the reaction between the high temperature alloy and the core material, the metal liquid in the small crucible enters the space between the core material and the casting through the flow pipe, and the metal liquid above the casting and the small crucible is heated and kept warm, and the casting below is cooled by the graphite cooling sleeve, so that the solid-liquid interface of the high temperature alloy melt is controlled below the casting inlet and above the bottom of the core material, so that the melt is solidified below the core material to form a pipe.

[0010] As a further design of the scheme, the drawing device is composed of an ingot head and an ingot rod, the ingot head is made of boron nitride ceramic material with high temperature resistance, high temperature alloy melt corrosion resistance and low thermal conductivity, which can avoid the reaction between the high temperature alloy and the core material, the ingot rod is made of ordinary steel, and the purpose is to uniformly draw the high temperature alloy pipe blank.

[0011] As a further design of the scheme, the thermocouple temperature measuring device is connected with the large crucible, the small crucible and the core material, which can realize real-time temperature control and real-time monitoring during the melting and keeping warm of the metal and the drawing and solidification of the blank, the temperature of the large crucible is not less than 1700 DEG C, the temperature of the small crucible is not less than 1000 DEG C, and the temperature of the casting outlet is lower than 200 DEG C, so that the casting and the core material maintain a large directional solidification gradient temperature, and the preparation of high quality high temperature alloy pipe blank is ensured.

[0012] (2) beneficial effects

[0013] The application provides a continuous casting equipment for high temperature alloy pipes.

[0014] (1) The device is mainly used for continuous casting forming of high temperature alloy pipes, the ingot head, the casting and the core material are made of materials with high temperature resistance, high temperature alloy melt corrosion resistance and low thermal conductivity, the ingot head is located in the heat preservation casting, the ingot head is cooled by water cooling from below, based on the principle of controlling metal heat transfer, the problem of high temperature alloy melting or serious surface oxidation caused by the temperature rise of the ingot head before the continuous casting of the melt is prevented, the temperature of the heat preservation casting cavity can be controlled in a large range, the process window of the continuous casting of the high temperature alloy pipe is widened, and the stability and interface quality of the continuous casting of the high temperature alloy pipe are improved.

[0015] (2) The device adopts graphite heating bodies to heat the smelting crucible and the heat preservation casting, which prevents the reaction between the high temperature alloy melt and the contact materials, ensures the accurate control of the temperature of the casting in contact with the melt, forms an axial temperature gradient in the casting, reduces the cold deformation resistance of the alloy, and realizes the continuous preparation of the high temperature alloy seamless pipe with high yield, high efficiency and high quality stability.

[0016] (3) The high-temperature alloy pipe prepared by the device can prepare high-temperature alloy pipes of various specifications by adjusting the structure of the casting mold and the core material, and the prepared high-temperature alloy pipe has good surface finish, compact structure, and uniform plastic processing performance, mechanical properties, physical properties and chemical composition, which are superior to the high-temperature alloy pipes of the same chemical composition prepared by using the traditional centrifugal casting technology. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 、 One A top view of a continuous casting equipment for high-temperature alloy pipes;

[0018] Figure 2 、 One A schematic diagram of a continuous casting equipment for high-temperature alloy pipes;

[0019] Figure 3 、 Figure 2 An enlarged view of area A in FIG. 1;

[0020] LIST OF REFERENCE NUMBERS: 1-flow channel; 2-large crucible; 3-induction coil; 4-water-cooled copper pipe; 5-core material; 6-supporting base; 7-graphite cooling sleeve; 8-dragging rod; 9-secondary water cooling device; 10-dragging head; 11-casting mold; 12-second induction heating device; 13-graphite heating body b; 14-small crucible; 15-graphite heating body a; 16-first thermocouple; 17-second thermocouple; 18-third thermocouple c; 19-fourth thermocouple. DETAILED DESCRIPTION

[0021] The present application will be further illustrated below in conjunction with the drawings and specific embodiments, and it should be understood that the following specific embodiments are only used to illustrate the present application and not to limit the scope of the present application. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "in" and "out" refer to the directions towards or away from the geometric center of a particular component.

[0022] Specific implementation cases:

[0023] Example 1: Prepare a GH2038 high-temperature alloy pipe with an outer diameter of 40 mm and a wall thickness of 4 mm.

[0024] The composition of the continuously cast GH2038 high-temperature alloy pipe according to the embodiment of the present application is shown in the following table. From the analysis of the content of the alloying elements in the experimental alloy, the material used in the present application is a high-purity alloy material with low impurity content and uniform composition. The content of Al and Ti is less than 1.5%, which effectively reduces the impurity content.

[0025] Table 1

[0026]

[0027] Put the GH2038 high-temperature alloy in the large crucible, start the induction heating device to heat the graphite, and then heat the high-temperature alloy in the large crucible to 1640℃ by the graphite heating and insulation device, and cool the induction coil by flowing 20L / min of cooling water; at the same time, start the thermocouple temperature measuring device, and collect temperature data in real time to control the temperature of the whole process of preparing the high-temperature alloy pipe; under the action of gravity, the molten metal in the large crucible flows into the small crucible for transition insulation, the induction heating device is started to heat the graphite, the graphite heating and insulation device is used to heat the melt in the small crucible to 1550℃ for 5min, and the graphite heating and insulation device is used to continuously heat the upper part of the mold to keep the temperature at 1450℃, and the graphite cooling copper sleeve is used to continuously cool the lower cooling section of the mold to ensure that the solid-liquid interface of the high-temperature alloy melt is controlled below the inlet of the mold and above the bottom of the core material; under the action of gravity, the high-temperature alloy melt in the small crucible enters the gap between the mold and the core material in the temperature control stage through the metal flow pipeline (the inner diameter of the mold is φ40mm, and the diameter of the core material is φ32mm); start the drawing mechanism, and draw the high-temperature alloy pipe blank by the initial drawing speed of 20mm / min with the aid of the dummy bar, and open the secondary cooling control mechanism to cool the pipe blank to a temperature of not higher than 35℃ with a cooling water flow of 10L / min, so that the pipe blank is further cooled and solidified to form a pipe blank; finally, the pipe blank is cut by a sawing machine to obtain a high-quality high-temperature alloy pipe blank with a desired length.

[0028] Table 2 Comparison of traditional method and the present method for producing φ40x4mm GH2038 high-temperature alloy pipe and performance

[0029]

[0030] Example 2: Preparation of K418 high-temperature alloy pipe with an outer diameter of 50mm and a wall thickness of 7mm.

[0031] The composition of the continuous casting K418 high-temperature alloy pipe according to the embodiment of the present application is shown in the following table. According to the analysis of the content of alloying elements in the experimental alloy, the material used in the present application is a high-purity alloy material with low impurity content and uniform composition. The content of Al and Ti is less than 1.5%, which effectively reduces the impurity content.

[0032] Table 1

[0033]

[0034] K418 high-temperature alloy is placed in a large crucible, the induction heating device is started to heat the graphite, then the graphite heating and heat preservation device is started to melt the high-temperature alloy in the large crucible at 1560 DEG C, the induction coil is cooled by a cooling water flow with a flow rate of 20 L / min for cooling protection; meanwhile, the graphite heating and heat preservation device and the thermocouple temperature measuring device are started, the temperature measuring device collects temperature data in real time, and temperature control is performed on the whole process of preparing the high-temperature alloy pipe; the molten metal in the large crucible flows into a small crucible under the action of gravity for transition heat preservation, the induction heating device is started to heat the graphite, the graphite heating and heat preservation device is started to heat the melt in the small crucible at 1460 DEG C for 10 min, and the graphite heating and heat preservation device is started to continuously heat the mold, so that the temperature is kept at 1460 DEG C; the graphite cooling copper sleeve continuously cools the lower cooling section of the mold, so that the solid-liquid interface of the high-temperature alloy melt is controlled below the mold inlet and above the bottom of the core material; the high-temperature alloy melt in the small crucible flows into the gap between the mold and the core material in the temperature control stage under the action of gravity through the metal flow pipeline (the inner diameter of the mold is 50 mm, and the diameter of the core material is 36 mm); the drawing mechanism is started, the solidified part of the alloy is drawn into the high-temperature alloy pipe blank by the dummy bar at an initial drawing speed of 20 mm / min, and the secondary cooling control mechanism is opened to cool the pipe blank at a temperature of not higher than 35 DEG C at a flow rate of 10 L / h, so that the pipe blank is further cooled and solidified to form a shape; finally, the pipe blank is sawn by a sawing machine to obtain a high-quality high-temperature alloy pipe blank with a required length.

[0035] Table 2 Comparison of traditional method and the method for producing φ40*4mm K418 high-temperature alloy pipe and performance

[0036]

[0037] The technical means disclosed in the scheme of the present application are not limited to the technical means disclosed in the above-mentioned embodiments, and also include technical solutions composed of any combination of the above technical features.

Claims

1. A continuous casting equipment for high-temperature alloy pipes, characterized in that, The utility model relates to a graphite crucible, induction heating device, graphite heating insulation device, drainage channel (1), core material (5), casting (11), thermocouple temperature measuring device, drawing device, graphite cooling jacket (7), support base (6), secondary water cooling device (9), the graphite crucible includes large crucible (2) and small crucible (14) are nested by graphite heating insulation device, and the large crucible (2) is above small crucible (14), and both sides are connected by the channel of same material quality, the core material (5) is wrapped in small crucible (14) below by casting (11), and the core material upper end is fixed in the middle of casting (11), surrounds a circle drainage channel (1), and the melt in small crucible (14) flows into the clearance between core material (5) and casting (11) by drainage channel (1), and the lower end of core material (5) is equipped with drawing device for drawing out pipe blank, the upper side of casting (11) is wrapped by graphite heating insulation device, and the lower side of casting (11) is cooled by graphite cooling jacket (7), controls the inside metal liquid cooling solidification gradient, and it is convenient for high quality pipe blank to form, the support base (6) is equipped with in the outermost side of whole equipment, plays the role of stable support, the secondary water cooling device (9) is outside the guide pin (8), and acts on high-temperature superalloy pipe blank and carries out secondary cooling.

2. The continuous casting apparatus for a superalloy pipe according to claim 1, wherein The crucible is made of a material that does not react with alloy elements in the high-temperature superalloy melt.

3. The continuous casting apparatus for a superalloy pipe according to claim 1, wherein The induction heating device includes first and second induction heating devices (12) located outside the graphite heating insulation devices above the large crucible (2) and the small crucible (14) and the casting, respectively, for melting and heat preservation of the metal.

4. The continuous casting apparatus for a superalloy tube as recited in claim 1, wherein The core material (5) is made of boron nitride, silicon carbide or zirconia ceramic material that is resistant to high temperature and high-temperature superalloy melt erosion and has low thermal conductivity, so that the high-temperature superalloy does not react with the core material. The metal liquid in the small crucible (14) enters the space between the core material (5) and the casting (11) through the drainage channel (1), and the metal liquid above the casting (11) and at the position of the small crucible (14) is heated and preserved. The casting (11) is cooled by the graphite cooling jacket (7) below, so that the solid-liquid interface of the high-temperature superalloy melt is controlled below the inlet of the casting (11) and above the bottom of the core material (5), and the melt solidifies into a pipe below the core material (5).

5. The continuous casting apparatus for a superalloy tube as recited in claim 1, wherein The drawing device includes a dummy head (10) and a guide pin (8), and the dummy head is made of boron nitride, silicon carbide or zirconia ceramic material that is resistant to high temperature and high-temperature superalloy melt erosion and has low thermal conductivity, so that the high-temperature superalloy does not react with the dummy head.

6. The continuous casting apparatus for a superalloy tube as recited in claim 1, wherein The thermocouple temperature measuring device comprises a first thermocouple (16), a second thermocouple (17), a third thermocouple (18) and a fourth thermocouple (19) connected with the large crucible (2), the small crucible (14) and the core material (5), can realize real-time temperature control in the smelting and heat preservation metal stage and the blank drawing and solidification stage, and can collect temperature data in real time, and guarantee preparation of high-quality high-temperature alloy pipe blanks.

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