Bimetal composite plate cast-rolling forming device and method

Abstract

The invention discloses a bimetal composite plate cast-rolling forming device and method, and belongs to the technical field of metal plate preparation. The device provided by the invention is composed of a coating molten metal casting system and a bimetal cladding-ingot pulling system, and the coating molten metal casting system and the bimetal cladding-ingot pulling system are arranged, so that the surface of a metal substrate is fully preheated and slightly melted by high-temperature slag liquid; the ingot pulling speed of the composite plate blank and the pouring speed of the coating metal liquid are adjusted and matched, the poured coating metal liquid penetrates through the liquid slag pool and then makes contact with the surface of the preheated metal base plate, effective element migration and diffusion are formed between the coating metal and the base plate metal, metallurgical bonding is formed, and then hot rolling is conducted to form a finished product. The bonding interface of the prepared bimetal composite plate has high cleanliness and strong bonding force, and the product specification limitation of the bimetal composite plate is broken through.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal plate preparation, and particularly relates to a casting and rolling forming device and method for a bimetallic composite plate. Background Art

[0002] Bimetallic composite plates can be widely used in the fields of wear resistance, corrosion resistance, etc. because they can optimize the matching of different performance materials according to their service performance requirements. Taking the stainless steel / carbon steel composite plate as an example, it is widely used in the fields of ships, automobiles, buildings, urban pipe corridors, etc. due to its low price and excellent comprehensive performance. At present, the main production methods of this composite plate are explosive cladding method, rolling cladding method, and explosive + rolling cladding method. Although the explosive cladding method can achieve the cladding of any metal parts, it has obvious defects such as pollution generated during explosion and difficulty in preparing thinner composite plates. The rolling cladding method for stainless steel / carbon steel composite plates mainly refers to vacuum hot rolling cladding. First, the surfaces of stainless steel and carbon steel plates are treated, and then billet assembling, welding, vacuum pumping, heating, and rolling are carried out. The thickness of the produced stainless steel / carbon steel composite plate is generally between 6 mm and 200 mm. However, even after vacuum pumping treatment after billet assembling and welding, there is still a certain oxygen partial pressure at the contact interface between stainless steel and carbon steel, and interface oxide inclusions are formed during subsequent hot rolling, seriously affecting the interface bonding performance of the stainless steel / carbon steel composite plate.

[0003] To reduce the interface oxidation problem in the preparation process of stainless steel / carbon steel composite plates, Chinese patents CN102179405A, CN116159861A, etc. respectively disclose measures such as adding nickel foil partitions and coating isolation agents between the stainless steel and carbon steel layers; Chinese patent CN102049478A discloses a solid-liquid continuous cladding device for stainless steel composite billets, realizing the continuous cladding production of stainless steel composite billets with solid stainless steel strips and ordinary structural steel molten steel as raw materials; Chinese patent CN114107683A discloses a method for preparing stainless steel / carbon steel composite cast billets by electroslag remelting connection, specifically forming a composite cast billet with carbon steel at the lower part and stainless steel at the upper part by the continuous melting of carbon steel electrodes and stainless steel electrodes, which has deficiencies such as obvious composition transition between the two metals and a large size of the performance transition section, and the need to make the cladding layer into a consumable electrode, increasing the production cost. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a casting and rolling forming device and method for a bimetallic composite plate, which has the advantages of high production efficiency, low production cost, and good bimetallic bonding quality.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A casting and rolling forming device for a bimetallic composite plate, which consists of a clad metal liquid casting system and a bimetallic cladding - ingot withdrawing system. The clad metal liquid casting system is located above the cladding - ingot withdrawing system; the said clad metal liquid casting system is composed of an induction heating tundish furnace body, tundish protective slag and a pouring speed control component; the bimetallic cladding - ingot withdrawing system includes a power supply, a power switch, a short - net, a water - cooled conductive mold, a high - temperature resistant insulating plate, a water - cooled trapezoidal mold, a water - cooled bottom mold, a water - cooled wide - face mold, a water - cooled narrow - face mold, clad metal liquid, a substrate to be compounded, a dummy bar, and a water - cooled bottom water tank;

[0007] The induction heating tundish furnace body includes a side ladle wall, an induction heat - retaining coil, a refractory heat - retaining lining, a liquid outlet and an induction heating tundish bottom ladle wall. The induction heat - retaining coil is installed in the side ladle wall, and the liquid outlet is opened on the refractory heat - retaining lining and the bottom ladle wall; the said pouring speed control component includes a hydraulic cylinder, an extension piece, a tundish sliding tube and a tundish immersion tube. The extension piece is slidably connected under the bottom ladle wall, the hydraulic cylinder is fixedly installed under the bottom ladle wall, the output end of the hydraulic cylinder is fixedly installed with the extension piece, the tundish sliding tube is fixedly installed on the side wall of the extension piece, the tundish immersion tube is fixedly installed at the bottom of the tundish sliding tube. The tundish sliding tube is communicated with the liquid outlet and the tundish immersion tube, and a slide rail slidably connected with the extension piece is fixedly installed at the bottom of the bottom ladle wall, and the cross - sectional shape of the slide rail is an inverted T - shape.

[0008] Furthermore, the water - cooled conductive mold includes a flange, a conductive graphite block, a water - cooled copper wall and hexagon bolts, and the hexagon bolts connect the flange, the conductive graphite block and the water - cooled copper wall in a threaded connection manner.

[0009] Furthermore, the water - cooled conductive mold, the water - cooled trapezoidal mold and the water - cooled bottom mold are connected in sequence from top to bottom; the high - temperature resistant insulating plate is in a "U" shape, insulating and separating the water - cooled conductive mold from the lower water - cooled trapezoidal mold and the two side water - cooled narrow - face molds. The water - cooled conductive mold, the water - cooled wide - face mold and the two water - cooled narrow - face molds jointly enclose a "mouth" - shaped cavity. Among them, the water - cooled conductive mold and the water - cooled wide - face mold are located on the wide faces of the "mouth" - shaped rectangular cavity and are opposite to each other, and the two opposite water - cooled narrow - face molds are on the narrow faces of the "mouth" - shaped rectangular cavity.

[0010] Furthermore, the substrate to be compounded is connected to the dummy bar by welding, the dummy bar is connected to the water - cooled bottom water tank by pins located at four corners, and the water - cooled bottom water tank is connected with a lead screw. The lead screw drives the water - cooled bottom water tank to move, and then drives the dummy bar, the substrate to be compounded and the solidified layer of the clad metal metallurgically bonded to the substrate to move downward.

[0011] Further, a slag-metal liquid level detector is provided above the water-cooled bottom mold, including an upper slag-metal liquid level detector and a lower slag-metal liquid level detector, which are used to monitor the real-time slag-metal interface to regulate the pouring speed of the clad metal and the ingot withdrawal speed of the composite slab, so as to achieve an effective match between the two.

[0012] A method for casting and rolling a bimetallic composite plate is realized based on the above device, and includes the following steps:

[0013] Step 1. Clean each surface of the substrate to be composite until there is no impurity residue, and then dry it. Clean the surface to be composite with ethanol and then dry it.

[0014] Step 2. Place the dried substrate to be composite into the bimetallic composite plate casting and rolling device, make the wide surface of the substrate to be composite contact with the water-cooled wide surface mold, and weld the bottom of the substrate to be composite to the dummy bar.

[0015] Step 3. Smelt the clad metal liquid with qualified composition and low impurity content through an induction melting device.

[0016] Step 4. Pour the melted clad metal liquid into the induction heating tundish for heating and heat preservation, and cover tundish protective slag above the clad metal liquid for heat preservation, gas isolation and oxidation prevention. The composition of the used tundish protective slag is 40% - 60% CaO, 30% - 50% Al 2 O 3 3, 5% - 15% SiO 2 2, 5% - 10% MgO, 0 - 5% CaF 2 2;

[0017] Step 5. Prepare and bake the slag for bimetallic composite. The composition of the used slag material is 40% - 60% CaF 2 2, 20% - 40% CaO, 20% - 30% Al 2 O 3 2, 0 - 5% MgO, 0 - 8% SiO 2 2 is configured, the above slag material is baked and dried, the baking temperature is 600°C - 800°C, the baking time is not less than 3h, and after baking, the slag is melted with a melting furnace.

[0018] Step 6. Pour the high-temperature slag liquid obtained by melting into the "mouth"-shaped cavity formed by the substrate to be composite and the mold. The liquid level of the high-temperature slag liquid is 50mm - 80mm higher than the lower edge of the conductive graphite ring, and turn on the power switch to conduct the conductive circuit of the bimetallic electroslag composite system; among them, the temperature of the slag liquid is 1600°C - 1650°C.

[0019] Step 7. A conductive loop is formed by the power supply - short network - water-cooled conductive crystallizer - slag for double-metal electroslag cladding - clad metal liquid + solidified layer of clad metal + substrate to be clad - dummy bar - water-cooled bottom water tank - short network - power supply. The current flows through the slag liquid to generate Joule heat, gradually heating and raising the temperature of the slag liquid until the temperature at the center position of the slag liquid reaches 1650 °C - 1800 °C. Meanwhile, the substrate to be clad is continuously preheated from the initial temperature (room temperature); among them, the parameters of loop voltage, current, and slag pool depth are set according to requirements;

[0020] Step 8. When the substrate to be clad is preheated to the set temperature, control the pouring speed control component of the induction heating tundish, and pour the clad metal liquid into the liquid slag pool. During the process of the clad metal liquid passing through the liquid slag layer, slag-metal reactions occur, further purifying and refining the clad metal liquid; among them, the set temperature is 10 °C - 30 °C lower than the solidus temperature of the substrate to be clad;

[0021] Step 9. With the pouring of the clad metal liquid, the metal liquid passing through the slag layer continuously deposits and forms a metal molten pool, which comes into contact with the surface of the well-preheated substrate to be clad and undergoes metallurgical bonding. Meanwhile, the pouring of the metal liquid causes the slag layer to move upward, affecting the stability of the conductive loop;

[0022] Step 10. To maintain the depth stability of the liquid slag layer submerging the lower edge of the conductive graphite ring, adjust and match the drawing speed of the substrate to be clad and the pouring speed of the clad metal liquid, and always control the actual slag-metal liquid level within the height range of the upper slag-metal liquid level detector and the lower slag-metal liquid level detector;

[0023] Step 11. As the double-metal cladding process continues, when the length of the substrate to be clad increases to the required length, stop pouring the clad metal liquid and drawing, continue to energize for 5 min - 10 min for hot capping and feeding, then turn off the power switch, and take out the double-metal clad slab after it cools down to obtain a double-metal clad slab;

[0024] Step 12. Send the double-metal clad slab into a heating furnace and heat it to 950 °C - 1150 °C; then, according to the corresponding rolling process, place the double-metal clad slab between the rolling rolls and use the controlled rolling and controlled cooling technology for rolling to finally obtain a double-metal clad plate with a good metallurgical bonding interface; among them, during the rolling process, the reduction rate per pass is not greater than 30%, and the rolling passes are determined according to the size of the double-metal clad slab and the requirements of the size of the rolled clad plate.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) In the bimetallic electroslag composite process, first, the high-temperature slag liquid fully preheats and slightly melts the surface of the metal substrate to remove the surface oxide layer, oil stains, etc.; secondly, the poured coating metal liquid passes through the liquid slag pool and contacts the preheated metal substrate surface to form a metallurgical bond. In this process, effective element migration and diffusion are formed between the coating metal and the substrate metal, and the bond is firm. Therefore, the bimetallic composite plate prepared by this method has a bonding interface with both high cleanliness (no oxide inclusions) and strong bonding force.

[0027] (2) The method provided by the present invention can be used to prepare bimetallic composite slabs with large thickness. Compared with the traditional hot-rolled composite method for directly preparing bimetallic composite plates, the hot-rolled material produced by the metallurgically bonded bimetallic composite slabs can greatly reduce the requirements for the rolling force of the rolling mill. That is, the bimetallic composite plates that can be prepared under the same rolling force of the rolling mill can be thicker, breaking through the product specifications of the bimetallic composite plates.

[0028] (3) The interface bonding quality control of the bimetallic composite slab preparation process is achieved by regulating the pouring temperature of the coating metal liquid, the power supply of the bimetallic electroslag composite process, the slag pool depth, and the size ratio of the coating to the substrate.

[0029] (4) The method provided by the present invention directly uses molten metal for bimetallic composite, which has a short process flow and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the casting and rolling process of bimetallic composite plates;

[0031] Figure 2 Schematic diagram of bimetallic electroslag composite process;

[0032] Figure 3 Schematic diagram of the cooling assembly on the wide side;

[0033] Figure 4 Inclusions at the interface of the stainless steel / carbon steel composite ingot in Example 1 of the present invention; wherein (a) is the interface inclusion situation of the conventional hot rolling composite method, (b) is the interface inclusion situation of the conventional hot rolling composite method, (c) is the interface inclusion situation of the casting and rolling forming method of the present invention, and (d) is the interface inclusion situation of the casting and rolling forming method of the present invention;

[0034] Figure 5 Microstructure of the stainless steel / carbon steel composite ingot bonding interface in Example 1 of the present invention; wherein (a) is the bonding condition of the edge interface of the stainless steel / carbon steel composite ingot, and (b) is a 100X magnified view of the edge interface;

[0035] Figure 6Tensile properties of the stainless steel / carbon steel composite casting billet with an interface specimen in Example 1 of the present invention; among them, (a) is the tensile curve of three parallel specimens at the same position; (b) is the tensile fracture position and microstructure morphology of the corresponding three specimens.

[0036] Figure 7 Microstructure and tensile properties of the bonding interface of the DC53 / 42CrMo composite casting billet in Example 2 of the present invention; among them, (a) is the tensile curve of two parallel specimens at the same position, (b) is the tensile fracture position and microstructure morphology of sample A1; (c) is the tensile fracture position and microstructure morphology of sample A2.

[0037] In the figure: 1 power supply, 2 power switch, 3 short network, 4 water-cooled conductive mold, 41 flange, 42 hexagon bolt, 43 conductive graphite ring, 44 water-cooled copper wall, 5 slag for double-metal electroslag composite, 6 clad metal liquid, 7 induction heating tundish furnace body, 71 side wall of the tundish, 72 induction heat preservation coil, 73 refractory heat preservation furnace lining, 74 liquid outlet, 8 bottom wall of the tundish, 9 casting speed control component, 91 hydraulic cylinder, 92 extension piece, 93 tundish sliding tube, 94 tundish immersion tube, 10 tundish powder, 11 substrate to be composite, 12 solidified layer of clad metal, 13 double-metal bonding interface, 14 dummy bar, 15 water-cooled bottom water tank, 16 high-temperature insulating board, 17 water-cooled trapezoidal mold, 18 water-cooled bottom mold, 19 water-cooled wide face mold, 20 slag-metal liquid level detector, 201 upper slag-metal liquid level detector, 202 lower slag-metal liquid level detector, 21 roll, 22 water-cooled narrow face mold. Detailed implementation manners

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0039] Example 1

[0040] This example provides a device and method for casting and rolling a bimetallic composite plate, and the casting and rolling process of the bimetallic composite plate is as Figure 1 shown.

[0041] The device for casting and rolling a bimetallic composite plate provided by the present invention comprises a clad metal liquid casting system and a bimetallic cladding-drawing system, and the clad metal liquid casting system is located above the bimetallic cladding-drawing system; the said clad metal liquid casting system is composed of an induction heating tundish furnace body 7, a tundish powder 10 and a casting speed control component 9; the composition of the bimetallic cladding-drawing system includes a power supply 1, a power switch 2, a short network 3, a water-cooled conductive mold 4, a high-temperature insulating board 16, a water-cooled trapezoidal mold 17, a water-cooled bottom mold 18, a water-cooled wide face mold 19, a water-cooled narrow face mold 22, a clad metal liquid 6, a substrate to be composite 11, a dummy bar 14, and a water-cooled bottom water tank 15.

[0042] The induction heating tundish furnace body 7 includes a side ladle wall 71, an induction heat preservation coil 72, a refractory heat preservation furnace lining 73, a liquid outlet 74, and an induction heating tundish bottom ladle wall 8. The induction heat preservation coil 72 is installed in the side ladle wall 71, and the liquid outlet 74 is opened on the refractory heat preservation furnace lining 73 and the bottom ladle wall 8. The pouring speed control assembly 9 includes a hydraulic cylinder 91, an extension 92, a tundish sliding tube 93, and a tundish immersion tube 94. The extension 92 is slidably connected under the bottom ladle wall 8. The hydraulic cylinder 91 is fixedly installed under the bottom ladle wall 8, and the output end of the hydraulic cylinder 91 is fixedly installed with the extension 92. The tundish sliding tube 93 is fixedly installed on the side wall of the extension 92, and the tundish immersion tube 94 is fixedly installed at the bottom of the tundish sliding tube 93. The tundish sliding tube 93 is communicated with the liquid outlet 74 and the tundish immersion tube 94. A slide rail slidably connected with the extension 92 is fixedly installed at the bottom of the bottom ladle wall 8, and the cross-sectional shape of the slide rail is an inverted T shape.

[0043] The water-cooled conductive mold 4 includes a flange 41, a conductive graphite block, a water-cooled copper wall 44, and hexagonal bolts 42. The hexagonal bolts 42 connect the flange 41, the conductive graphite block, and the water-cooled copper wall 44 by means of threaded connection.

[0044] In this embodiment, the bimetal cladding - ingot withdrawal system is as Figure 2 shown, and the schematic diagram of the cooling component on the wide face side is shown in Figure 3 . The water-cooled conductive mold 4, the water-cooled trapezoidal mold 17, and the water-cooled bottom mold 18 are connected in sequence from top to bottom. The high-temperature insulating board 16 is in a "U" shape, and insulates and separates the water-cooled conductive mold 4 from the lower water-cooled trapezoidal mold 17 and the two water-cooled narrow face molds 22 on both sides. The water-cooled conductive mold 4, the water-cooled wide face mold 19, and the two water-cooled narrow face molds 22 together enclose a "mouth" - shaped cavity. Among them, the water-cooled conductive mold 4 and the water-cooled wide face mold 19 are located on the wide face of the "mouth" - shaped rectangular cavity and are opposite to each other, and the two opposite water-cooled narrow face molds 22 are on the narrow face of the "mouth" - shaped rectangular cavity.

[0045] The substrate to be clad 11 is connected to the dummy bar 14 by welding. The dummy bar 14 is connected to the water-cooled bottom water tank 15 by pins located at the four corners. The water-cooled bottom water tank 15 is connected with a lead screw, and the lead screw drives the water-cooled bottom water tank 15 to move, thereby driving the dummy bar 14, the substrate to be clad 11, and the clad metal solidified layer 12 metallurgically bonded to the substrate to move downward. A slag-metal liquid level detector 20 is arranged above the water-cooled bottom mold 18, including an upper slag-metal liquid level detector 201 and a lower slag-metal liquid level detector 202, which monitors the real-time slag-metal interface to regulate the pouring speed of the clad metal and the ingot withdrawal speed of the composite slab, so as to achieve an effective match between the two.

[0046] A method for preparing a cast-rolling formed stainless steel / carbon steel composite plate provided by this embodiment, according to the bimetal size ratio of the stainless steel / carbon steel composite plate and the cast-rolling forming process characteristics of the present invention, determines that the thin-sized 304 stainless steel is the base plate and the thick-sized Q235 carbon steel is the clad metal, and is realized by the above device, and specifically carried out according to the following steps;

[0047] Step 1: Mechanically clean the surface of the 304 stainless steel base plate and wash it with anhydrous ethanol until there is no impurity residue on the surface, and then dry it.

[0048] Step 2: Place the dried base plate into the rectangular mold of the liquid-solid composite process of the clad metal and the base plate, make its wide surface closely adhere to the inner side of the water-cooled wide surface mold 19, and weld the bottom to the dummy bar 14;

[0049] Step 3: Melt the Q235 clad metal in an intermediate frequency induction furnace, its composition meets the requirements of national standard GB / T700-2024, and control the content of oxygen and sulfur impurities in the steel to be lower than 30 ppm, heat it up to 1600 °C and keep it warm for 10 min;

[0050] Step 4: Then pour it into the induction heating tundish, energize the induction coil of the tundish, adjust the temperature of the Q235 clad metal liquid 6 to 1560 °C and keep it warm, cover the tundish protective slag 10 above the molten steel for heat preservation, gas isolation and oxidation prevention, and the composition of the tundish protective slag 10 is 45% CaO - 35% Al 2 O 3 -10% SiO 2 -7% MgO - 3% CaF 2 configured, and its melting temperature is about 1200 °C;

[0051] Step: 5: Configure the slag 5 for bimetal electroslag composite according to 60% CaF 2 -20% CaO - 20% Al 2 O 3 configured, and its melting temperature is about 1287 °C; the slag material is baked at 800 °C for 6 h and then melted in an induction furnace;

[0052] Step 6: After the slag is melted and clarified, pour it into the rectangular cavity surrounded by the stainless steel base plate and the water-cooled mold, and make the liquid level of the slag liquid higher than the lower edge of the conductive graphite ring 43 of the water-cooled conductive mold 4 by 60 mm, and turn on the power switch 2 to conduct the conductive circuit of the bimetal electroslag composite system;

[0053] Step 7: Set the voltage and current of the conductive circuit, the voltage is 28 V - 35 V, the current is 2000 A - 3500 A, further increase the slag temperature and preheat the stainless steel base plate;

[0054] Step 8: When the surface of the stainless steel substrate measured at a fixed position above the water-cooled conductive mold 4 is preheated to 400°C to 500°C, start the pouring speed control component 9 at the lower part of the induction heating tundish, and start pouring the carbon steel liquid; wait for the carbon steel liquid to pass through the slag for double-metal electroslag composite to obtain further refining and purification;

[0055] Step 9: Under the action of the surrounding water-cooled mold and the bottom water-cooled bottom water tank 15, the poured Q235 steel liquid gradually completes metallurgical bonding with the preheated stainless steel substrate surface and solidifies;

[0056] Step 10: While pouring the Q235 steel liquid, adjust the drawing speed of the composite slab to make it well match the pouring speed of the steel liquid, and always control the actual slag-metal interface within the height range of the upper slag-metal liquid level detector 201 and the lower slag-metal liquid level detector 202;

[0057] Step 11: As the double-metal electroslag composite process progresses, the length of the drawn stainless steel / carbon steel composite slab continuously increases. When it reaches the required length, stop pouring and drawing; continue to energize for 5 min to 10 min for hot capping and feeding, and then turn off the power switch 1. After the composite slab cools, take it out, and the preparation of the stainless steel / carbon steel composite slab is completed. The inclusions and microstructure of the bimetallic bonding interface 13 are as attached Figure 4 、 Figure 5 shown. The tensile strength of the interface composite specimen in the as-cast state is as high as over 465 MPa, far higher than the national standard requirements.

[0058] Step 12: Send the composite slab into the heating furnace and heat it to 1200°C; place the composite slab between the rolling rolls 21, and then roll it according to the corresponding hot rolling process. During the rolling process, the reduction ratio per pass is not greater than 30%. Determine the rolling passes according to the size of the composite slab billet and the size requirements of the rolled composite slab, and finally obtain a stainless steel / carbon steel composite plate with a good metallurgical bonding interface (the tensile properties of the stainless steel / carbon steel composite slab billet containing the interface specimen are as Figure 6 ).

[0059] Example 2

[0060] This example uses the same double-metal composite plate casting and rolling forming device as in Example 1.

[0061] This example provides a casting and rolling forming preparation method for a wear-resistant steel / alloy structural steel composite plate. The wear-resistant steel used is high-carbon and high-alloy DC53 (Cr8Mo2SiV) steel, and the alloy structural steel used is 42CrMo steel. The composition of the slag 5 for double-metal electroslag composite is by mass percentage CaF 2 44%, CaO 36%, Al 2 O 3 15%, SiO 25%, the melting temperature of the slag is about 1176 °C; during the bimetallic electroslag composite process, the voltage of the conductive circuit is 28 - 32 V and the current is 2000 - 3000 A. The rest of the method is the same as that of Example 1. The microstructure and tensile properties of the as-cast bonding interface of the DC53 / 42CrMo bimetallic composite slab are as shown in the appendix Figure 7 As shown, the tensile property test results of the interfacial composite specimen show that the tensile fracture does not occur at the bimetallic bonding interface, fully indicating the high bimetallic bonding strength.

[0062] The above technical solutions elaborate on the technical idea of the present invention. The protection scope of the present invention cannot be limited thereby. Any modification and decoration made to the above technical solutions based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A bimetallic composite plate casting and rolling forming device, characterized in that: It consists of a clad metal liquid casting system and a bimetal cladding - ingot withdrawing system. The clad metal liquid casting system is located above the cladding - ingot withdrawing system. The clad metal liquid casting system is composed of an induction heating tundish furnace body, tundish protective slag, and pouring speed control components. The bimetal cladding - ingot withdrawing system includes a power supply, a power switch, a short - net, a water - cooled conductive mold, a high - temperature resistant insulating board, a water - cooled trapezoidal mold, a water - cooled bottom mold, a water - cooled wide - face mold, a water - cooled narrow - face mold, clad metal liquid, a substrate to be compounded, a dummy bar, and a water - cooled bottom water tank.

2. A bimetallic composite plate casting and rolling forming device according to claim 1, characterized in that: The induction heating tundish furnace body includes a side tundish wall, an induction heat - retaining coil, a refractory heat - retaining lining, a liquid outlet, and an induction heating tundish bottom wall. The induction heat - retaining coil is installed in the side tundish wall, and the liquid outlet is opened on the refractory heat - retaining lining and the bottom wall. The pouring speed control components include a hydraulic cylinder, an extension piece, a tundish sliding tube, and a tundish immersion tube. The extension piece is slidably connected under the bottom wall. The hydraulic cylinder is fixedly installed under the bottom wall, and the output end of the hydraulic cylinder is fixedly installed with the extension piece. The tundish sliding tube is fixedly installed on the side wall of the extension piece, and the tundish immersion tube is fixedly installed at the bottom of the tundish sliding tube. The tundish sliding tube is communicated with the liquid outlet and the tundish immersion tube. A slide rail slidably connected with the extension piece is fixedly installed at the bottom of the bottom wall, and the cross - sectional shape of the slide rail is an inverted T - shape.

3. The bimetallic composite plate casting and rolling forming device according to claim 1, characterized in that: The water - cooled conductive mold includes a flange, a conductive graphite block, a water - cooled copper wall, and hexagonal bolts. The hexagonal bolts connect the flange, the conductive graphite block, and the water - cooled copper wall in a threaded connection manner. The water - cooled conductive mold, the water - cooled trapezoidal mold, and the water - cooled bottom mold are connected in sequence from top to bottom. The high - temperature resistant insulating board is in a "U" shape and insulates and separates the water - cooled conductive mold from the lower water - cooled trapezoidal mold and the two side water - cooled narrow - face molds. The water - cooled conductive mold, the water - cooled wide - face mold, and the two water - cooled narrow - face molds jointly enclose a "square" - shaped cavity. Among them, the water - cooled conductive mold and the water - cooled wide - face mold are located on the wide faces of the "square" - shaped rectangular cavity and are opposite to each other. The two opposite water - cooled narrow - face molds are on the narrow faces of the "square" - shaped rectangular cavity.

4. The bimetallic composite plate casting and rolling forming device according to claim 1, characterized in that: The substrate to be compounded is connected to the dummy bar by welding. The dummy bar is connected to the water - cooled bottom water tank by pins at four corners. The water - cooled bottom water tank is connected with a lead screw, and the lead screw drives the water - cooled bottom water tank to move, thereby driving the dummy bar, the substrate to be compounded, and the solidified layer of the clad metal metallurgically bonded to the substrate to move downward.

5. The bimetallic composite plate casting and rolling forming device according to claim 1, characterized in that: A slag - metal liquid level detector is arranged on the upper part of the water - cooled bottom mold, including an upper slag - metal liquid level detector and a lower slag - metal liquid level detector, which real - time monitors the slag - metal interface, regulates the pouring speed of the clad metal and the ingot withdrawing speed of the substrate to be compounded, and realizes the effective matching of the two.

6. A method for casting and rolling a bimetallic composite plate, implemented by using the device according to any one of claims 1 to 4, characterized in that: It includes the following steps: Step 1. Clean each surface of the substrate to be compounded until there is no impurity residue and then dry it. Clean the surface to be compounded with ethanol and then dry it. Step 2. Place the dried substrate to be compounded into the bimetal composite plate casting and rolling forming device, make the wide face of the substrate to be compounded contact with the water - cooled wide - face mold, and weld the bottom of the substrate to be compounded to the dummy bar. Step 3. Melting the cladding metal liquid by induction melting equipment; Step 4: pouring the coating metal liquid into the induction heating tundish for heating and heat preservation, and covering the coating metal liquid with tundish protection slag for heat preservation, gas isolation and oxidation prevention; Step 5. Prepare and bake the bimetallic composite slag, prepare the bimetallic composite slag according to the set ratio, bake and dry it, and then use a smelting furnace to melt the slag to obtain high-temperature slag liquid; Step 6. Pour the high-temperature slag liquid obtained by smelting into the "mouth"-shaped cavity surrounded by the substrate to be composited and the crystallizer, start the power switch, and the conductive circuit of the bimetallic electroslag composite system is turned on; Step 7. A conductive circuit is formed by power supply-short net-water-cooled conductive crystallizer-bimetallic electroslag composite slag-coating metal liquid+coating metal solidified layer+substrate to be composited-starting plate-water-cooled bottom water tank-short net-power supply, and the slag liquid is gradually heated and heated up, and at the same time, the substrate to be composited is continuously preheated from the initial temperature; Step 8. When the substrate to be composited is preheated to the set temperature, the induction heating tundish pouring speed control component is controlled to pour the coating metal liquid into the liquid slag pool. The coating metal liquid undergoes a slag-metal reaction when passing through the liquid slag layer, and the coating metal liquid is further purified and refined; wherein the set temperature is that the temperature of the substrate to be composited is 10°C to 30°C lower than its solidus temperature; Step 9. As the coating metal liquid is poured in, the metal liquid that passes through the slag layer is continuously deposited and forms a molten metal pool, which contacts the surface of the substrate to be composited that has been well preheated and undergoes metallurgical bonding; Step 10. Adjust and match the composite substrate ingot extraction speed and the coating metal liquid pouring speed to always control the actual slag metal liquid level within the height range of the upper slag metal liquid level detector and the lower slag metal liquid level detector; Step 11. As the bimetallic composite process continues, when the length of the substrate to be composited increases to the required length, the pouring of the coating metal liquid and the withdrawal of the ingot are stopped, and the power is continued to be turned on for 5 to 10 minutes for hot capping and shrinkage compensation, and then the power switch is turned off, and the composite substrate is taken out after cooling to obtain a bimetallic composite slab; Step 12. Place the bimetallic composite slab into a heating furnace and heat it to 950°C to 1150°C; then place the bimetallic composite slab between rollers according to the corresponding rolling process, and roll it using controlled rolling and controlled cooling technology to finally obtain a bimetallic composite plate with a good metallurgical bonding interface; wherein, during the rolling process, the reduction rate of each pass is not greater than 30%, and the rolling passes are determined according to the size of the bimetallic composite slab and the size requirements of the composite plate after rolling.

7. A casting and rolling method for a bimetallic composite plate according to claim 6, characterized in that: In step 4, the components of the tundish protection slag are CaO 40% to 60%, Al2O3 30% to 50%, SiO2 5 to 15%, MgO 5 to 10%, and CaF2 0 to 5% by mass percentage.

8. The casting and rolling forming method of a bimetallic composite plate according to claim 6, characterized in that: In step 5, the composition of the bimetallic composite slag is CaF2 40%-60%, CaO 20%-40%, Al2O3 20%-30%, MgO0-5%, SiO2 0-8% by mass percentage; the baking temperature is 600°C-800°C, and the baking time is not less than 3h.

9. A bimetallic composite plate casting and rolling forming method according to claim 6, characterized in that: In step 6, the liquid level of the high-temperature slag liquid is 50 mm to 80 mm higher than the lower edge of the conductive graphite ring; the temperature of the slag liquid is 1600° C. to 1650° C.

10. The casting and rolling forming method of a bimetallic composite plate according to claim 6, characterized in that: In step 7, the temperature at the center of the slag liquid is raised to 1650°C to 1800°C; the initial temperature is room temperature; in the conductive circuit, the circuit voltage, current, and slag pool depth parameters are set as needed.

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