CN111390141A - Preparation method of double-layer or multi-layer metal composite pipe rod parison - Google Patents

Abstract

The invention relates to a preparation method of a double-layer or multi-layer metal composite pipe rod parison, which comprises the following steps: a. preparing raw materials; b. preparing a casting mold; c. filling a mold; d. casting and compounding; e. cooling and forming; f. preparing a multilayer metal composite blank; the invention realizes that the bimetallic composite pipe bar parison is obtained by adopting a conventional die casting method, and the metal composite pipe bar section bar can be obtained by subsequent plastic deformation, and has low production cost and good composite effect.

Description

A kind of preparation method of double-layer or multi-layer metal composite pipe rod parison

technical field

The invention relates to the technical field of metal material composite casting, in particular to a method for preparing a double-layer or multi-layer metal composite pipe rod parison.

Background technique

Double-layer or multi-layer metal composite materials are usually made of stainless steel, titanium alloy, nickel-based alloy, hard wear-resistant materials, etc. as the cladding material, and carbon steel, low-alloy steel and other cheap metals as the base material, which are combined by metallurgical methods. . This kind of composite material not only has the advantages of high strength, high plastic toughness, excellent welding performance and low production cost of the base material, but also has the characteristics of corrosion resistance, wear resistance, oxidation resistance, gorgeous appearance and so on of the coating material. The incomparable price advantage and performance of cladding materials. Therefore, the use of double-layer or multi-layer metal composites instead of single cladding materials has broad application prospects. Because of its high efficiency, high yield, and high output, composite rolling has so far been the best choice for preparing bi-layer or multi-layer metal composites. The composite billet is a necessary raw material for rolling composite materials. In view of the particularity of the plastic deformation of the pipe-rod profile, the composite billet prepared by the conventional casing welding method is usually difficult to withstand the repeated alternating tensile and compressive stress during rolling, which is easy to cause rolling. During the process, delamination and cracking occurred between the cladding and the substrate, resulting in failure of the composite. Therefore, it is of great significance to prepare double-layer or multi-layer metal clad pipe and rod parisons that meet the rolling requirements.

At present, there are many methods for preparing bimetallic composite steel pipe blanks. The most commonly used method is the nesting method, that is, the inner and outer surfaces of the pipe blanks to be composited are cleaned first, and then the small diameter pipe blanks are inserted into the large diameter pipe blanks. The end of the composite billet is welded and sealed, and after cold drawing or cold expansion, diffusion annealing is performed to form a composite tube blank or a composite tube. Chinese patent publications CN103982711A, CN103464508A, CN103481033A, CN102274853A, CN102537531A, CN104384859A, etc. all adopt the method of first nesting and compounding, and then performing pressure processing to prepare composite pipes. The biggest disadvantage of this type of method is that the process is cumbersome, the production efficiency is low, and a large plastic deformation is required to eliminate the gap between the coating and the substrate. The patent publications CN101670383A, CN101566256A, JPH02229616A, etc. adopt the brazing method to make billets. This method adds an isolation layer between two kinds of tube billets, which can prevent the formation of interface brittle compounds and improve the interface toughness. The interfacial bond strength can be improved by using larger plastic deformation. Chinese patent publications CN103962558A, CN101934370B, etc. adopt spray forming technology to spray another metal melt on the outer surface of the inner tube blank to prepare a composite tube blank. Although this method can obtain a surface fine-grained or ultra-fine-grained metal layer, it is The metal thickness of the surface layer is not easy to control, the injection molding efficiency is not high, and the process parameters are not easy to control. Japanese Patent Publication JPH0292436A adopts the method of continuous casting of double molds to prepare composite steel pipes. The composite pipe blank prepared by this method has the advantages of high interface bonding strength and high production efficiency. However, when continuous casting with double molds is used, the crystallization of liquid metal can be accurately controlled. It's very difficult. Chinese patent publication CN104588436A firstly uses the lost foam casting method to cast the inner layer thin-walled high alloy corrosion-resistant tube blank, and then uses the sand casting method to cast the outer layer carbon steel tube blank outside the high alloy tube blank to make a bimetallic composite tube blank. The method adopts a two-step sand casting method, and the process is complicated, the preparation efficiency is low, and the production cost is high. Patent publications CN101530898A, CN101704084A, CN101530907A, CN101804450A, CN102581250A, US5558150A, JPH0890190A, etc. all adopt the method of composite preparation of tube blanks by centrifugal casting. This type of method uses centrifugal casting equipment to pour the two metal melts to be compounded into the centrifugal casting mold in batches and layers, so that the two metal materials form metallurgical fusion at the interface. The composite tube blank cast by this method has high interface bonding strength, but the disadvantage is that the interfacial area is seriously mixed, the process is relatively complicated, and the production cost is high.

SUMMARY OF THE INVENTION

The invention provides a method for preparing a double-layer or multi-layer metal composite tube-rod parison, which realizes that the bimetallic composite tube-rod parison is obtained by a conventional casting method, and the metal composite tube-rod profile can be obtained by subsequent plastic deformation. The production cost is low and the composite quality is good.

In order to achieve the above object, the present invention adopts the following technical solutions to realize:

A method for preparing a double-layer or multi-layer metal composite pipe rod parison, comprising the following steps:

a. Preparation of raw materials: Select the outer metal material of the composite tube and rod parison as the material to be cast, and use the smelting device to melt the outer metal material to obtain a liquid metal melt; select the inner layer metal material of the composite tube and rod parison as the waiting material composite solid material, and process it into a solid metal core blank, process 2 positioning bolt holes at the bottom of the solid metal core blank, remove the oxide skin on the surface of the solid metal core blank, and clean and dry the surface;

b. Preparing the casting mold: Design the shape and size of the casting mold according to the shape and size of the composite tube and rod parison. The casting mold is composed of a mold body and a mold bottom; It is a symmetrical structure, which is relatively buckled together, and is locked by a plurality of fastening bolts to form a mold cavity; the shape of the mold bottom is the same as that of the composite pipe rod parison, and the top of the mold bottom is provided with a boss, the shape of the boss, The size corresponds to the shape and size of the mold cavity. The mold body and the mold bottom are inserted into the mold cavity through the boss for positioning and fixing, and the bottom of the mold cavity is closed at the same time; two positioning bolt through holes and positioning bolt through holes are processed on the mold bottom. The position of the die corresponds to the position of the two positioning bolt holes at the bottom of the solid metal core blank; the side of the die bottom is provided with a plurality of connecting bolt through holes; the lower part of the die body is provided with a plurality of corresponding connecting bolt holes;

c. Loading the mold: Preheat the mold bottom, the mold body and the solid metal core blank, seat the solid metal core blank at the center of the mold bottom, pass the two positioning bolts through the two positioning bolt through holes and then tighten them on the corresponding Position the bolt holes so that the bottom of the die and the solid metal core blank are connected as a whole; the die body is seated on the bottom of the die, the lower part of the die cavity is sleeved on the outside of the boss, and a plurality of connecting bolts are passed through the through holes of the connecting bolts and then tightened. Connect the bolt holes to make the mold body, the mold bottom and the solid metal core blank as a whole; put the mold body, the mold bottom and the solid metal core blank assembly into the protective atmosphere chamber, cover the cover plate on the top of the protective atmosphere chamber, and A sprue cup is installed on the top of the cover plate, an annular nozzle is arranged at the bottom of the sprue cup, the lower end of the annular nozzle is inserted into the protective atmosphere chamber, and the annular molten steel outlet of the annular nozzle faces the annular gap between the solid metal core blank and the mold body below;

d. Casting compound: Fill inert gas into the protective atmosphere chamber through the inlet and exhaust pipes on the protective atmosphere chamber, and discharge the air in the protective atmosphere chamber. When the protective atmosphere chamber is completely filled with inert gas, the pre-melted liquid metal will be smelted in advance. The melt is poured into the sprue cup, and the liquid metal melt is injected into the annular gap between the solid metal core blank and the mold body through the annular nozzle at the bottom of the sprue cup;

e. Cooling and forming: After the liquid metal melt is poured, the liquid metal melt in the mold body surrounds the solid metal core blank and solidifies to form a composite blank. Open the cover plate on the top of the protective atmosphere chamber. After the composite blank is cooled to the set temperature, the The casting mold and the composite billet are taken out from the protective atmosphere chamber, and then the positioning bolts, connecting bolts and fastening bolts are removed to obtain a double-layer metal composite pipe rod parison;

f. Preparation of multi-layer metal composite blanks: using the bimetallic composite blanks as solid metal core blanks, repeating steps a to e to obtain a multi-layer metal composite tube-rod parison.

Mechanical or chemical methods are used to remove iron oxide scale.

The mold body and the mold bottom are cast by cast iron, or welded with steel plates.

When preparing a hollow composite tube blank, the solid metal core blank is a hollow tubular structure, and when preparing a solid composite tube rod parison, the solid metal core blank is a solid rod body structure.

The pouring cup is composed of a cup wall, a refractory material layer, a connecting rib plate, a cup bottom and an annular nozzle. The cup wall is a funnel-shaped structure with a large upper mouth and a small lower mouth. The lower mouth of the cup wall and the bottom of the cup are connected and fixed by a plurality of connecting ribs arranged at intervals, so that an annular channel is formed between the cup wall and the bottom of the cup, and the annular channel is correspondingly connected with the annular nozzle; the refractory material layer is coated on the cup wall The inner surface of the cup bottom, the upper surface of the cup bottom and the outer surface of the connecting rib.

The cup wall, the cup bottom and the connecting ribs are fixed by welding.

After reheating the prepared double-layer metal clad tube-rod parison or multi-layer metal cladding tube-rod parison, through forging, rolling, extrusion, drawing or other metal calendering, the double-layer or multi-layer metal cladding is finally obtained. Composite tube and rod profiles.

Compared with the prior art, the beneficial effects of the present invention are:

(1) Compared with the existing solid-solid composite billet-making method, the present invention adopts the liquid-solid casting composite billet-making process, and the technological process is greatly simplified, eliminating the need for surface processing and sheathing in the solid-solid composite method. , welding, sealing and vacuuming processes, the composite efficiency is greatly improved, the process cost is reduced, and the comprehensive production cost is reduced;

(2) Compared with the existing solid-solid phase composite blank-making method, the present invention adopts the liquid-solid casting composite blank-making method, and the inner layer solid metal core blank is covered by the outer layer liquid metal melt to solidify, and the shrinkage solidification structure Compressive stress is generated on the inner solid metal core blank, there is no gap between the inner and outer layers of materials, and element diffusion occurs at high temperature, so the liquid-solid interface can be combined more firmly, so that the final composite blank is of better quality .

Description of drawings

FIG. 1 is a schematic diagram of the process of preparing a double-layer metal composite tube and rod parison by the method of the present invention.

FIG. 2 is an A-A view in FIG. 1 .

Figure 3 is a top view of the pouring cup of the present invention.

FIG. 4 is a schematic diagram of the process of preparing a hollow composite tube blank by the method of the present invention.

In the figure: 1. Mould bottom 2. Connecting bolts 3. Mould body 4. Fastening bolts 5. Protective atmosphere chamber 6. Intake and exhaust pipes 7. Cover plate 8. Sprue cup 81. Cup wall 82. Refractory layer 83. Connecting ribs 84. Annular nozzle 85. Cup bottom 9. Solid metal core blank 10. Liquid metal melt 11. Positioning bolt

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

As shown in Figure 1, Figure 2, Figure 4, the method for preparing a double-layer or multi-layer metal composite pipe rod parison according to the present invention includes the following steps:

a. Preparation of raw materials: Select the outer metal material of the composite tube and rod parison as the material to be cast, and use the smelting device to melt the outer metal material to obtain a liquid metal melt; select the inner layer metal material of the composite tube and rod parison as the waiting material composite solid material, and process it into a solid metal core blank 9, process 2 positioning bolt holes at the bottom of the solid metal core blank 9, remove the oxide skin on the surface of the solid metal core blank 9, and clean the surface and dry it;

b. Prepare the casting mold: Design the shape and size of the casting mold according to the shape and size of the composite tube and rod parison. The casting mold consists of a mold body 3 and a mold bottom 1; , the mold groove is a symmetrical structure, which is relatively buckled together, and the mold cavity is formed after being locked by a plurality of fastening bolts 4; , the shape and size of the boss correspond to the shape and size of the mold cavity. The mold body 3 and the mold bottom 1 are inserted into the mold cavity through the boss for positioning and fixing, and the bottom of the mold cavity is closed at the same time; 2 positioning is processed on the mold bottom. Bolt through holes, the positions of the positioning bolt through holes correspond to the positions of the two positioning bolt holes at the bottom of the solid metal core blank 9; the side of the die bottom 1 is provided with a plurality of connecting bolt through holes; the lower part of the die body 3 is provided with a plurality of corresponding connection Bolt hole;

c. Loading the mold: Preheat the mold bottom 1, the mold body 3 and the solid metal core blank 9, seat the solid metal core blank 9 at the center of the mold bottom 1, and pass the two positioning bolts 11 through the two positioning bolts. After the holes are tightened in the corresponding positioning bolt holes, the die bottom 1 and the solid metal core blank 9 are connected into a whole; The bolts 2 pass through the connecting bolt through holes and then are tightened in the connecting bolt holes, so that the mold body 3, the mold bottom 1 and the solid metal core blank 9 form a whole; the mold body 3, the mold bottom 1 and the solid metal core blank 9 are assembled into pieces Put it into the protective atmosphere chamber 5, cover the cover plate 7 on the top of the protective atmosphere chamber 5, and install the pouring cup 8 on the top of the cover plate 7. The bottom of the pouring cup 8 is provided with an annular nozzle 84, and the lower end of the annular nozzle 84 is inserted into In the protective atmosphere chamber 5, the annular molten steel outlet of the annular nozzle 84 is facing the annular gap between the solid metal core blank 9 and the die body 3 below;

d. Casting compound: Fill the protective atmosphere chamber 5 with inert gas through the inlet and exhaust pipes 6 on the protective atmosphere chamber 5, and discharge the air in the protective atmosphere chamber 5. When the protective atmosphere chamber 5 is completely filled with inert gas , pour the pre-melted liquid metal melt 10 into the sprue cup 8, and the liquid metal melt 10 is injected into the annular gap between the solid metal core blank 9 and the mold body 3 through the annular nozzle 84 at the bottom of the sprue cup 8 ;

e. Cooling and forming: After the liquid metal melt 10 is poured, the liquid metal melt 10 in the mold body 3 surrounds the solid metal core blank 9 and solidifies to form a composite blank, open the cover plate 7 on the top of the protective atmosphere chamber 5, and wait for the composite blank to cool. After reaching the set temperature, the casting mold and the composite billet are taken out from the protective atmosphere chamber 5, and then the positioning bolts 11, the connecting bolts 2 and the fastening bolts 4 are removed to obtain a double-layer metal composite pipe rod parison;

f. Preparation of multi-layer metal composite blanks: using the bimetallic composite blanks as solid metal core blanks, repeating steps a to e to obtain a multi-layer metal composite tube-rod parison.

Mechanical or chemical methods are used to remove iron oxide scale.

Both the mold body 3 and the mold bottom 1 are made of cast iron or welded with steel plates.

When preparing a hollow composite tube blank, the solid metal core blank 9 is a hollow tubular structure, and when preparing a solid composite tube rod parison, the solid metal core blank 9 is a solid rod body structure.

As shown in FIG. 3 , the sprue cup 8 is composed of a cup wall 81, a refractory material layer 82, a connecting rib 83, a cup bottom 85 and an annular nozzle 84. The cup wall 81 is in the shape of a funnel with a large upper opening and a small lower opening. Structure, the bottom 85 of the cup is arranged at the lower mouth of the cup wall 81, the lower mouth of the cup wall 81 and the cup bottom 85 are connected and fixed by a plurality of connecting ribs 83 arranged at intervals, so that the gap between the cup wall 81 and the cup bottom 85 is fixed. An annular channel is formed, and the annular channel is correspondingly connected with the annular nozzle 84;

The cup wall 81, the cup bottom 85, and the connecting rib plate 83 are all made of ordinary steel, and the three are fixed by welding.

After reheating the prepared double-layer metal clad tube-rod parison or multi-layer metal cladding tube-rod parison, through forging, rolling, extrusion, drawing or other metal calendering, the double-layer or multi-layer metal cladding is finally obtained. Composite tube and rod profiles.

The following examples are implemented on the premise of the technical solutions of the present invention, and provide detailed embodiments and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[Example 1]

In this example, 304 stainless steel is used as the cladding material, and Q345 low-alloy steel is used as the inner layer material to prepare a 304/Q345 bimetallic composite round bar. In the finished bimetal composite round bar, the thickness of the 304 stainless steel cladding material is 20mm, the diameter of the Q345 low alloy steel inner layer material is φ200mm, the outer diameter of the finished product is φ240mm, and the length is 2000mm. The specific preparation process is as follows:

a. Select 304 stainless steel as the outer layer material to be cast, and use an induction furnace to melt the 304 stainless steel to obtain a 304 stainless steel melt; select a Q345 ordinary carbon steel bar with a diameter of 202mm and a length of 2050mm as the inner layer material to be composited. Two M16×20mm locating bolt holes are processed at the bottom of the steel core, and the iron oxide scale on the surface of the Q345 steel core is removed by mechanical processing, and then the surface is cleaned and dried;

b. According to the size of the ingot, the casting mold is designed to be circular. The casting mold consists of a mold body and a mold bottom. The mold body is composed of two cast iron mold grooves with lugs. The wall thickness of the mold groove is 12mm; There are fastening bolt holes in the height direction, and 8 M16×80mm fastening bolts are used to connect the two mold grooves together to form a mold cavity. The inner diameter of the mold cavity is φ240mm and the length is 2250mm. The cross section of the die bottom is circular, and the top of the die bottom is machined with a boss with a diameter of 239.8mm, and the height of the boss is 15mm. Two φ20mm through holes for positioning bolts are machined on the bottom of the die. The position of the through holes for the positioning bolts is the same as The positions of the 2 positioning bolt holes at the bottom of the Q345 steel core correspond to;

c. Preheat the mold bottom, mold body and Q345 steel core to 120~150℃, sit the Q345 steel core on the mold bottom, use M16 positioning bolts to pass through the positioning bolt through holes of the mold bottom, and connect the mold bottom to the Q345 The steel core is connected as a whole; then the mold body is seated on the mold bottom, so that the mold cavity is set on the boss of the mold bottom, and M12 connecting bolts are used to connect the mold body and the mold bottom together. Put the mold body, mold bottom and Q345 steel core assembly into the protective atmosphere chamber, cover the cover plate on the top of the protective atmosphere chamber, install the sprue cup on the top of the cover plate, the bottom of the sprue cup is provided with an annular nozzle, the annular nozzle The size is φ214 (inner diameter)/φ226mm (outer diameter), the lower end of the annular nozzle is inserted into the protective atmosphere chamber, aiming at the annular gap between the Q 345 steel core and the mold body;

d. Fill the protective atmosphere chamber with 99.99% high-purity argon through the inlet and exhaust pipes, replace the air in the protective atmosphere chamber, and then inject the pre-melted 304 stainless steel melt into the mold through the sprue cup and annular nozzle Inside, the Q345 steel core is surrounded by 304 stainless steel melt and solidifies;

e. After the 304 stainless steel melt is completely solidified, open the cover on the top of the protective atmosphere chamber, take out the casting mold and the composite billet, and then remove the positioning bolts, connecting bolts, and fastening bolts to obtain 304 stainless steel/Q345 low-alloy steel bimetallic composite The bar billet is made of this composite bar billet as raw material, through perforation and tube rolling, 304 stainless steel/Q345 low alloy steel bimetal composite steel pipe is obtained.

[Example 2]

As shown in Figure 1 and Figure 2, in this embodiment, 2205 duplex stainless steel is used as the cladding material, and 20MnSi low alloy steel is used as the inner layer material to prepare a 2205 duplex stainless steel/20MnSi low alloy steel bimetallic composite rectangular bar , In the finished product of bimetallic composite rectangular bar, the thickness of 2205 duplex stainless steel cladding is 20mm, the cross-sectional dimension of 20MnSi low alloy steel core is 240×320mm, and the length of the finished product is 2000mm. Specific steps are as follows:

a. Select 2205 duplex stainless steel as the outer layer material to be cast, and use an induction furnace to melt the 2205 duplex stainless steel to obtain a 2205 duplex stainless steel melt; select 20MnSi low-alloy square steel with a section size of 200×280mm as the solid metal to be composited Steel core, its length is 2050mm. Two M16×20mm locating bolt holes were machined at the bottom of the 20MnSi steel core, and the iron oxide scale on the surface of the 20MnSi steel core was removed by grinding, and then the surface was cleaned and dried;

b. According to the size of the ingot, the mold is designed to be rectangular. The mold consists of a mold body and a mold bottom. The mold body is composed of two cast iron mold grooves with lugs. The thickness of the mold groove is 20mm. There are multiple fastening bolt holes, and 8 M16×80mm fastening bolts are used to connect the two mold grooves together to form a mold cavity. The cross-sectional size of the mold cavity is 240×

320mm, length is 2250mm. The cross section of the die bottom is rectangular, the top of the die bottom is processed with a rectangular boss with a size of 240×320mm, and the height of the boss is 20mm. The bottom of the mold bottom is machined with 2 through holes of φ20mm positioning bolts, and the positions of the through holes of the positioning bolts correspond to the positions of the two positioning bolt holes at the bottom of the 20MnSi steel core;

c. Preheat the mold bottom, mold body and 20MnSi steel core to 120~150℃, place the Q 235 steel core on the mold bottom, use M16 positioning bolts to pass through the positioning bolt through holes of the mold bottom, and connect the mold bottom to the 20MnSi steel core. The steel core is connected as a whole; then the mold body is seated on the mold bottom, the mold cavity is set on the rectangular boss of the mold bottom, and M16 connecting bolts are used to connect the mold body and the mold bottom together. Put the assembly of the mold body, the mold bottom and the 20MnSi steel core into the protective atmosphere chamber, cover the cover plate on the top of the protective atmosphere chamber, install the pouring cup on the top of the cover plate, the bottom of the pouring cup is provided with an annular nozzle, the annular nozzle The cross section of the die is rectangular, and the lower end of the annular nozzle is inserted into the protective atmosphere chamber, aiming at the annular gap between the 20MnSi steel core and the mold body;

d. Fill the protective atmosphere chamber with 99.99% high-purity argon through the inlet and exhaust pipes to replace the air in the protective atmosphere chamber, and then pass the pre-melted 2205 duplex stainless steel melt through the sprue cup and annular nozzle Inject into the casting mold, so that the 2205 duplex stainless steel melt surrounds the 20MnSi steel core and solidifies;

e. After the 2205 duplex stainless steel melt is completely solidified, open the cover on the top of the protective atmosphere chamber, take out the casting mold and the composite billet, and then remove the positioning bolts, connecting bolts, and fastening bolts to obtain 2205 duplex stainless steel/20MnSi low alloy Steel bimetallic composite rectangular bar billet, the bimetallic rectangular bar billet is blanked, and then rolled by a high-speed wire mill to obtain 2205 duplex stainless steel/20MnSi steel bimetallic composite threaded steel bar.

[Example 3]

As shown in FIG. 4 , in this embodiment, Q215 plain carbon steel is used as the base material, and TA2 titanium alloy is used as the inner layer material to prepare a Q215 plain carbon steel/TA2 titanium alloy bimetal composite tube blank. In the finished bimetal composite tube blank, the thickness of the Q215 plain carbon steel base material is 100mm, the thickness of the TA2 titanium alloy inner layer material is 40mm, and the length of the finished product is 1500mm. The specific preparation process is as follows:

a. Select Q215 steel as the outer layer material to be cast, and use a melting furnace to melt Q215 steel to obtain a Q215 steel melt; select TA2 titanium alloy pipes with a diameter of 200mm and a wall thickness of 40mm as the inner layer material to be compounded, TA2 titanium The length of the alloy tube is 1550mm. One end of the TA2 titanium alloy pipe is closed with an end plate, and two M10×15mm positioning bolt holes are machined on the end plate. The oxide scale on the surface of the TA2 titanium alloy pipe is removed with a wire brush, and then the surface is washed and dried. ;

b. According to the size of the ingot, the casting mold is designed to be circular. The casting mold is composed of a mold body and a mold bottom. The mold body is composed of two cast iron mold grooves with lugs. The thickness of the mold groove is 20mm, and eight M16× The 80mm fastening bolts connect the two mold grooves together to form a mold cavity. The inner diameter of the mold cavity is φ400mm and the length is 1600mm. The bottom of the die is round, the top of the die bottom is machined with a φ400mm boss, the height of the boss is 40mm, and the bottom of the die bottom is machined with two φ16mm through holes for positioning bolts, and the positions of the through holes for the positioning bolts are the same as the bottom of the TA2 titanium alloy tube The positions of the positioning bolt holes correspond to;

c. Preheat the mold bottom, mold body and TA2 titanium alloy tube to 100~120℃, place the TA2 titanium alloy tube on the mold bottom, use M10 positioning bolts to pass through the positioning bolt through holes of the mold bottom, and connect the mold bottom to the mold bottom. The TA2 titanium alloy tube is connected as a whole; then the mold body is seated on the mold bottom, the mold cavity is set on the boss of the mold bottom, and the mold body and the mold bottom are connected together with M16 connecting bolts. Put the assembly of mold body, mold bottom and TA2 titanium alloy tube into the protective atmosphere chamber, cover the cover plate on the top of the protective atmosphere chamber, install the pouring cup on the top of the cover plate, and there is an annular nozzle at the bottom of the pouring cup. The size of the nozzle is φ320 (inner diameter)/φ335mm (outer diameter), and the lower end of the annular nozzle is inserted into the protective atmosphere chamber and aligned with the annular gap between the TA2 titanium alloy tube and the mold body;

d. Fill the protective atmosphere chamber with 99.99% high-purity argon through the inlet and exhaust pipes to replace the air in the protective atmosphere chamber, and then inject the pre-melted Q235 steel melt into the mold through the sprue cup and the annular nozzle Inside, the TA2 titanium alloy tube is surrounded by Q235 steel melt and solidifies;

e. After the Q235 steel melt is completely solidified, open the cover at the top of the protective atmosphere chamber, take out the casting mold and the composite billet, and then remove the positioning bolts, connecting bolts, and fastening bolts to obtain TA2 titanium alloy tube/Q235 plain carbon steel double Metal composite tube blank, further rolling the bimetal composite tube blank to obtain TA2 titanium alloy tube/Q235 plain carbon steel bimetal composite tube.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (7)

1. a preparation method of double-layer or multi-layer metal composite pipe rod parison, is characterized in that, comprises the following steps: a. Preparation of raw materials: Select the outer metal material of the composite tube and rod parison as the material to be cast, and use the smelting device to melt the outer metal material to obtain a liquid metal melt; select the inner layer metal material of the composite tube and rod parison as the waiting material composite solid material, and process it into a solid metal core blank, process 2 positioning bolt holes at the bottom of the solid metal core blank, remove the oxide skin on the surface of the solid metal core blank, and clean and dry the surface; b. Preparing the casting mold: Design the shape and size of the casting mold according to the shape and size of the composite tube and rod parison. The casting mold is composed of a mold body and a mold bottom; It is a symmetrical structure, which is relatively buckled together, and is locked by a plurality of fastening bolts to form a mold cavity; the shape of the mold bottom is the same as that of the composite pipe rod parison, and the top of the mold bottom is provided with a boss, the shape of the boss, The size corresponds to the shape and size of the mold cavity. The mold body and the mold bottom are inserted into the mold cavity through the boss for positioning and fixing, and the bottom of the mold cavity is closed at the same time; two positioning bolt through holes and positioning bolt through holes are processed on the mold bottom. The position of the die corresponds to the position of the two positioning bolt holes at the bottom of the solid metal core blank; the side of the die bottom is provided with a plurality of connecting bolt through holes; the lower part of the die body is provided with a plurality of corresponding connecting bolt holes; c. Loading the mold: Preheat the mold bottom, the mold body and the solid metal core blank, seat the solid metal core blank at the center of the mold bottom, pass the two positioning bolts through the two positioning bolt through holes and then tighten them on the corresponding Position the bolt holes so that the bottom of the die and the solid metal core blank are connected as a whole; the die body is seated on the bottom of the die, the lower part of the die cavity is sleeved on the outside of the boss, and a plurality of connecting bolts are passed through the through holes of the connecting bolts and then tightened. Connect the bolt holes to make the mold body, the mold bottom and the solid metal core blank as a whole; put the mold body, the mold bottom and the solid metal core blank assembly into the protective atmosphere chamber, cover the cover plate on the top of the protective atmosphere chamber, and A sprue cup is installed on the top of the cover plate, an annular nozzle is arranged at the bottom of the sprue cup, the lower end of the annular nozzle is inserted into the protective atmosphere chamber, and the annular molten steel outlet of the annular nozzle faces the annular gap between the solid metal core blank and the mold body below; d. Casting compound: Fill inert gas into the protective atmosphere chamber through the inlet and exhaust pipes on the protective atmosphere chamber, and discharge the air in the protective atmosphere chamber. When the protective atmosphere chamber is completely filled with inert gas, the pre-melted liquid metal will be smelted in advance. The melt is poured into the sprue cup, and the liquid metal melt is injected into the annular gap between the solid metal core blank and the mold body through the annular nozzle at the bottom of the sprue cup; e. Cooling and forming: After the liquid metal melt is poured, the liquid metal melt in the mold body surrounds the solid metal core blank and solidifies to form a composite blank. Open the cover plate on the top of the protective atmosphere chamber. After the composite blank is cooled to the set temperature, the The casting mold and the composite billet are taken out from the protective atmosphere chamber, and then the positioning bolts, connecting bolts and fastening bolts are removed to obtain a double-layer metal composite pipe rod parison; f. Preparation of multi-layer metal composite blanks: using the bimetallic composite blanks as solid metal core blanks, repeating steps a to e to obtain a multi-layer metal composite tube-rod parison. 2 . The method for preparing a double-layer or multi-layer metal composite tube and rod parison according to claim 1 , wherein a mechanical method or a chemical method is used when the scale is removed. 3 . 3. the preparation method of a kind of double-layer or multi-layer metal composite pipe rod parison according to claim 1, is characterized in that, described mould body and mould bottom all adopt cast iron to cast, or adopt steel plate welding to make and make. to make. 4. The method for preparing a double-layer or multi-layer metal composite tube bar parison according to claim 1, wherein when preparing a hollow composite tube blank, the solid metal core blank is a hollow tubular structure, and a solid metal core blank is prepared. When compounding the tube and rod parison, the solid metal core blank is a solid rod body structure. 5. The method for preparing a double-layer or multi-layer metal composite tube and rod parison according to claim 1, wherein the pouring cup is composed of a cup wall, a refractory material layer, a connecting rib, a cup bottom and a It consists of an annular nozzle. The wall of the cup is a funnel-shaped structure with a large upper mouth and a small lower mouth. The bottom of the cup is located at the lower mouth of the cup wall. The lower mouth of the cup wall and the bottom of the cup are connected by a plurality of connecting ribs arranged at intervals. Fix, so that an annular channel is formed between the cup wall and the cup bottom, and the annular channel is connected with the annular nozzle correspondingly; the refractory material layer is coated on the inner surface of the cup wall, the upper surface of the cup bottom and the outer surface of the connecting rib. 6 . The method for preparing a double-layer or multi-layer metal composite tube and rod parison according to claim 5 , wherein the cup wall, the cup bottom and the connecting ribs are fixed by welding. 7 . 7. The method for preparing a double-layer or multi-layer metal clad pipe rod parison according to claim 1, wherein the prepared double-layer metal clad pipe rod parison or multi-layer metal clad pipe rod parison After the billet is reheated, it is processed by forging, rolling, extrusion, drawing or other metal calendering to finally obtain double-layer or multi-layer metal clad pipe and rod profiles.

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