CN105499545A - Method for preparing double-metal composite material by solid-liquid combination of solid-state steel material and rolling composition - Google Patents

Abstract

The invention discloses a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel; the method includes the steps of preparing a bimetallic rolling blank by solid-liquid composite casting and rolling the blank to prepare a bimetallic composite material A step of. The present invention is characterized in that it utilizes the process means of solid-liquid connection after the surface zinc layer is protected, which solves a series of problems such as air holes, burn-through, and excessive thickness of the intermediate compound layer that are easy to occur when traditional welding methods are used to connect steel and other materials, and overcomes the problems of steel and other materials. It is easy to form an oxide film on the surface at high temperature to hinder the formation of metallurgical bonding between steel and other materials, and then form it by rolling to break the intermediate compound formed on the interface during the solid-liquid composite process, improving the bimetallic composite material and matrix material. mechanical and physical properties. The invention does not need gas protection, simple composite technology, wide process conditions and easy operation, simple process equipment requirements, high interface bonding strength, and good electrical and thermal conductivity.

Description

Method for preparing bimetallic composite material by solid-liquid compounding and rolling combination of solid steel

technical field

The invention belongs to the field of preparation of bimetallic composite materials, and specifically relates to a method for preparing bimetallic composite materials through solid-liquid composite casting and rolling combination of solid steel, that is, a method for preparing bimetallic composite materials through solid-liquid composite casting followed by rolling combination technology Methods.

Background technique

With the development of modern industrial technology, the requirements for the comprehensive performance of materials are getting higher and higher. Under many working conditions, it is difficult for a single component metal material to meet the requirements. Therefore, the research and preparation of new composite materials has become an important development direction in the field of materials science and engineering. Bimetallic composite material is a new type of composite material prepared by combining two metals with different properties through various composite technologies. Compared with single-element metal materials, bimetallic composite materials can comprehensively utilize the physical and chemical properties of the two metal materials to obtain comprehensive properties that single-element metals cannot have at the same time, which can better meet the rapid development of industry and technology. Higher and higher requirements are placed on materials. Compared with single metal materials, its advantages are embodied in the following three aspects: (1) excellent comprehensive performance; (2) good economic benefits; (3) extensive designability.

Due to its excellent comprehensive mechanical properties, steel is widely used in aviation, machinery, automobile, petroleum, construction and other industries, and is one of the most widely used metals. After investigation, it was found that bimetallic composites formed by combining steel and other materials, such as steel-aluminum bimetallic composites, steel-magnesium bimetallic composites, etc., have received more and more attention. However, when using traditional welding methods to prepare bimetallic composites, various defects often appear due to the large difference in physical and chemical properties between the two metals. For example, steel-aluminum bimetallic materials, the melting point difference between the two metals is close to 1000°C, so it is difficult to achieve welding. At the same time, a series of problems such as pores, burn-through, and excessive thickness of the intermediate compound layer often appear in the welded joints. According to the search of the prior art, it is found that, in addition to the welding method, the common methods of steel-aluminum composite can be divided into solid-liquid composite, solid-solid composite and liquid-liquid composite according to the state of the material. For solid connection methods, such as extrusion, the production efficiency is high, but because aluminum and titanium are very easy to oxidize in the atmospheric environment, especially under high temperature conditions, a dense oxide film will be formed between the two metals, and the oxide film Presence will hinder the formation of metallurgical bonds. The liquid-liquid connection is often limited by equipment, and there are very strict requirements on the shape and size of the material, which also limits the promotion and application of bimetallic materials such as steel-magnesium and steel-aluminum to a certain extent. Compared with solid-solid composite and liquid-liquid composite, solid-liquid composite technology has simple procedures, less constraints on shape conditions, simple process equipment requirements, and higher production efficiency, and is receiving more and more attention. However, solid-liquid composites also have certain deficiencies. After searching, it was found that Mechanical testing of steel/aluminium-silicon interfaces by pushout (Study on the mechanical properties of steel and aluminum-silicon alloy interfaces) published by Dezellus et al. , in the liquid-solid composite process, when the pouring temperature is high, it is easy to generate a thicker intermediate compound on the interface, which affects the bonding strength and physical properties of the steel-aluminum bimetallic composite. It can be seen that each method has its unique advantages, but also has certain limitations.

A further search of the prior art found that researchers began to prepare bimetallic composites by combining two composite methods to overcome the shortcomings of a single method. Chinese patent CN101364459A discloses a production method and equipment for a copper-clad aluminum busbar. This technology uses extrusion and hot rolling to prepare copper-aluminum bimetallic composite materials, but because it uses two solid connection methods, and in order to avoid the influence of oxide film, inert gas protection is introduced in the heat treatment process. and higher preparation conditions. Chinese patent CN101465171A discloses a method for continuously manufacturing copper-clad aluminum busbars by cladding welding and rolling. This technology uses clad welding and rolling combination method to prepare copper-aluminum bimetallic composite materials, but also uses two solid connection methods, and in order to avoid the influence of oxide film, an inert gas protection is introduced in the heat treatment process , higher requirements for equipment and preparation conditions.

Contents of the invention

In view of the defects in the prior art, the purpose of the present invention is to provide a method for preparing bimetallic composite materials by combining solid-liquid composite casting and rolling of solid steel, so as to solve the problem of the formation of joint regions often caused by the existing composite technology when connecting steel and other materials A series of problems such as pores, oxide slag inclusions, burn-through, etc., while solving a series of problems such as the existence of oxide films and intermediate compounds that seriously affect the interaction between the two metals and the low performance of bimetallic composites, make the two A metallurgical bond is formed between the two alloys, which has excellent mechanical properties.

The present invention is achieved through the following technical solutions:

The invention provides a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel. The method includes the steps of preparing a bimetallic rolling blank by solid-liquid composite casting and rolling the blank to prepare a bimetallic composite material. step.

Preferably, the step of preparing the bimetal rolling blank by solid-liquid composite casting specifically includes:

Treatment preset: Surface treatment is carried out on the solid copper preset material to be connected, and it is preset in the mold cavity after treatment;

Casting combination: pouring the liquid material to be poured into the cavity of the mold, and casting to form a bimetal rolling billet.

Preferably, the casting material includes a metal or alloy with a melting point lower than or equal to that of solid steel; wherein the metal or alloy includes aluminum, magnesium, steel, and the like. When the pouring material is steel, because there are many types of steel, although they are all steel, different types of steel can be selected, and the different performance advantages of different steels can also be combined to obtain bimetallic composite materials with excellent performance.

Preferably, in the pre-treatment step, the surface treatment specifically refers to a galvanized protective layer;

Preferably, the implementation of the zinc protective layer includes electroplating, electroless plating, hot-dip plating, thermal spraying, vapor deposition, etc.; the thickness of the zinc protective layer is 0.1-50 μm. If the zinc layer is too thin, it will vaporize before pouring, and the surface will then oxidize, which cannot play a protective role. Too thick will cause the zinc layer to not fully dissolve into the castable material, resulting in failure to form a metallurgical bond. Or there is zinc aggregation at the metallurgical bonding interface, which will affect the performance of the bimetallic composite.

Preferably, in the step of combining casting, the casting method includes sand casting, metal casting, low pressure casting, high pressure casting, vacuum casting, squeeze casting, centrifugal casting and the like.

Preferably, in the step of casting bonding, the pouring temperature is 450-1800°C; the pouring temperature is lower than 450°C, it is difficult to fill the mold, and at the same time it is difficult to melt the surface zinc layer, so metallurgical bonding cannot be formed. Higher than 1800°C may cause severe melting of the preset steel, which loses its significance as a high-performance preset material; further preferably, the pouring temperature is 650-1800°C; especially preferably, the pouring temperature is 1600-1800°C ℃.

Preferably, in the step of rolling the billet to prepare bimetallic composite material, the rolling method is double-layer rolling or three-layer rolling; the rolling is cold rolling, warm rolling or hot rolling; the rolling The rolling temperature is -100°C to 100°C below the melting point of the casting material; the rolling reduction rate is 10-75%, and the rolling speed is 0.01-10m/s. When the rolling temperature is lower than -100°C, the formability is poor, and defects such as cracks will appear during the rolling process. When the temperature is higher than the upper limit, it is possible to reach the melting point of the pouring material or even the steel, resulting in the melting of the material and failing to form the required bimetallic material. When the reduction rate is lower than 10%, there is basically no deformation effect, and the damage effect on the intermediate compound is very weak, and there will be a thicker intermediate compound on the interface of the obtained material, which will affect the performance. And lower than 0.01m/s, the production efficiency is low. Further preferably, the rolling temperature is -100°C to 500°C.

Preferably, the step of rolling the billet to prepare the bimetallic composite further includes annealing the obtained bimetallic composite after rolling.

Preferably, the temperature of the annealing treatment is 100° C. to 100° C. below the melting point of the casting material, and the time of the annealing treatment is 5 to 300 minutes. When the temperature is lower than 100°C or the time is less than 5 minutes, the stress relief effect cannot be achieved, and the interaction between the two metals is weak, and it is difficult to react, resulting in poor performance of the bimetallic composite. When the temperature is higher than the upper limit or the time is longer than 300 minutes, the two metals react violently, and the thickness of the intermediate compound layer will be very thick. The hard and brittle nature of the intermediate compound will affect the performance of the bimetallic composite material, or it may exceed the performance of the castable material or even the steel. Melting point, which causes the material to melt and cannot form bimetallic materials. Further preferably, the temperature of the annealing treatment is 300-400°C.

Preferably, the step of rolling the billet to prepare the bimetallic composite material further includes annealing the obtained bimetallic rolled billet before rolling.

Preferably, the temperature of the annealing treatment before rolling is 100° C. to 100° C. below the melting point of the castable material, and the annealing treatment time is 0 to 300 minutes. Rolling may be performed without heat treatment before rolling. If the heat treatment before rolling is carried out, when the temperature is lower than 100°C, the effect of stress relief cannot be achieved. When the temperature is higher than the upper limit or the time is longer than 300min, the two metals react violently, the thickness of the intermediate compound layer will be very thick, and defects such as cracks may appear, which will affect the rolling process and the performance of the obtained bimetallic composite material, or cause Castable materials and even solid steel preforms melt and cannot form the desired bimetallic composite.

Compared with other existing technologies, the present invention has the following beneficial effects:

1. Compared with the traditional welding method, it avoids the occurrence of problems such as pores, oxidized slag inclusions, burn-through, and excessive thickness of the intermediate compound layer;

2. Compared with the single liquid-liquid composite method, it has lower requirements for equipment, and lower requirements for the shape and size of materials;

3. Compared with the single solid-solid composite method, the problem of surface oxide film is solved, and a uniform and continuous zinc layer can be formed on the surface of the solid steel preset material, so that the physical properties of the bimetallic composite material can reach a higher level;

4. Compared with the single solid-liquid composite method, it solves the problem that a thicker intermediate compound will be formed on the interface when the pouring temperature is not well controlled, and improves the mechanical and physical properties of the bimetallic composite material. Compared with the single solid-liquid composite method Composite, stripping performance improvement is very obvious. At the same time, the properties of the steel and castable matrix materials have also been improved.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Figure 1 is a schematic diagram of the preparation of bimetallic composite materials by combining solid-liquid composite casting and rolling after the solid steel is preset, in which 1 is the solid preset steel material, and 2 is the liquid casting molding material.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

The composite material obtained in the embodiment of the present invention is shown in FIG. 1 ; wherein, 1 is a solid preset steel material, and 2 is a liquid cast molding material.

Example 1

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel, including the following steps:

Step 1. Perform thermal spraying zinc surface treatment on the pre-installed material of the solid Q235A structural steel to be connected, and the thickness of the zinc layer is 10 μm;

Step 2, presetting the surface-treated solid Q235A structural steel at the required position in the mold cavity;

Step 3: Melt 6101 extruded aluminum alloy in the cavity of the resistance furnace, use the processing technology of metal mold casting, and the pouring temperature is 750°C, so that the metallurgical bond between steel and aluminum is formed;

Step 4. Perform annealing treatment on the obtained Q235-6101 steel-aluminum bimetallic rolling billet before rolling. The annealing temperature is 100° C. and the time is 100 minutes. 150℃, rolling speed 5m/s;

Step 5. Put the obtained steel-aluminum bimetallic composite material into an annealing furnace for post-rolling annealing treatment. The annealing temperature is 100° C. and the annealing time is 300 minutes.

After testing, it was found that there were no defects such as pores, oxidized slag inclusions, burn-through, and excessive thickness of the intermediate compound layer in the bonding area. A metallurgical bond is formed between the two materials, and there is a continuous distribution of intermetallic compounds in the interface area, indicating that a metallurgical bond is formed between the two metals. After testing, the performance of the steel-aluminum bimetallic composite material is good, and the peel strength is 48N/mm.

Example 2

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel, including the following steps:

Step 1. Perform thermal spraying zinc surface treatment on the solid 316L stainless steel preset material to be connected, and the thickness of the zinc layer is 25 μm;

Step 2, presetting the surface-treated solid 316L stainless steel at the required position in the mold cavity;

Step 3: Melt the A356 cast aluminum alloy in the resistance furnace and pour it into the mold cavity. Using the processing technology of squeeze casting, the pouring temperature is 650°C, and the squeeze casting pressure is 70MPa to form a metallurgical bond between steel and aluminum;

Step 4. Perform annealing treatment on the obtained 316L-A356 steel-aluminum bimetallic rolling billet before rolling. The annealing temperature is 300° C. for 20 minutes, and then hot rolling is continued. The reduction rate is 60%, and the rolling temperature 450℃, rolling speed 5m/s;

Step 5. Put the obtained steel-aluminum bimetallic composite material into an annealing furnace for post-rolling annealing treatment. The annealing temperature is 100° C. and the annealing time is 200 minutes.

After testing, it was found that there were no defects such as pores, oxidized slag inclusions, burn-through, and excessive thickness of the intermediate compound layer in the bonding area. A metallurgical bond is formed between the two materials, and there is a continuous distribution of intermetallic compounds in the interface area, indicating that a metallurgical bond is formed between the two metals. After testing, the performance of the steel-aluminum bimetallic composite material is good, and the peel strength is 55N/mm.

Example 3

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel, including the following steps:

Step 1. Perform thermal spraying zinc surface treatment on the solid 316L stainless steel preset material to be connected, and the thickness of the zinc layer is 25 μm;

Step 2, presetting the surface-treated solid 316L stainless steel at the required position in the mold cavity;

Step 3: Melt the AZ91 magnesium alloy in the resistance furnace and pour it into the mold cavity. Using the processing technology of squeeze casting, the pouring temperature is 700 ° C, and the squeeze casting pressure is 50 MPa to form a metallurgical bond between steel and magnesium;

Step 4, the obtained 316L-AZ91 steel-magnesium bimetallic rolling billet is annealed before rolling, the annealing temperature is 350°C, the time is 5min, and then the warm rolling process is continued, the reduction rate is 40%, the rolling temperature 100℃, rolling speed is 10m/s;

Step 5. Put the obtained steel-magnesium bimetallic composite material into an annealing furnace for post-rolling annealing treatment. The annealing temperature is 100° C. and the annealing time is 5 minutes.

After testing, it was found that there were no defects such as pores, oxidized slag inclusions, burn-through, and excessive thickness of the intermediate compound layer in the bonding area. A metallurgical bond is formed between the two materials, and there is a continuous distribution of intermetallic compounds in the interface area, indicating that a metallurgical bond is formed between the two metals. After testing, the performance of the steel-magnesium bimetallic composite material is good, and the peel strength is 50N/mm.

Example 4

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel, including the following steps:

Step 1. Perform thermal spraying zinc surface treatment on the solid 16MnL low-alloy high-strength steel preset material to be connected, and the thickness of the zinc layer is 50 μm;

Step 2, presetting the surface-treated solid 16MnL low-alloy high-strength steel at the required position in the mold cavity;

Step 3: Melt the AZ31 magnesium alloy in the resistance furnace and pour it into the mold cavity. Using the sand casting process, the pouring temperature is 720°C, so that the metallurgical bond between the steel and the magnesium is formed;

Step 4, continue hot-rolling the obtained 16MnL-AZ31 magnesium steel, the reduction rate is 70%, the rolling temperature is 100°C, and the rolling speed is 0.5m/s;

Step 5. Put the obtained steel-magnesium bimetallic composite material into an annealing furnace for post-rolling annealing treatment. The annealing temperature is 200° C. and the annealing time is 60 minutes.

After testing, it was found that there were no defects such as pores, oxidized slag inclusions, burn-through, and excessive thickness of the intermediate compound layer in the bonding area. A metallurgical bond is formed between the two materials, and there is a continuous distribution of intermetallic compounds in the interface area, indicating that a metallurgical bond is formed between the two metals. After testing, the performance of the steel-magnesium bimetallic composite material is good, and the peel strength is 48N/mm.

Example 5

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel, including the following steps:

Step 1. Electrogalvanizing surface treatment is carried out on the preset material of solid 16MnL low-alloy high-strength steel to be connected, and the thickness of the zinc layer is 0.1 μm;

Step 2, presetting the surface-treated solid 16MnL low-alloy high-strength steel at the required position in the mold cavity;

Step 3. Melt Q235 structural steel in the resistance furnace and pour it into the mold cavity. Using the processing technology of squeeze casting, the pouring temperature is 1600 ° C, and the squeeze casting pressure is 50 MPa to form a metallurgical bond between steel and steel;

Step 4: Perform annealing treatment on the obtained 16MnL-Q235 steel bimetallic rolling billet before rolling, the annealing temperature is 300°C, the time is 10min, then continue the cold rolling process, the reduction rate is 10%, the rolling temperature -100℃, rolling speed is 0.01m/s;

Step 5. Put the obtained steel-steel bimetallic composite material into an annealing furnace for post-rolling annealing treatment. The annealing temperature is 300° C. and the annealing time is 50 minutes.

After testing, it is found that there are no defects such as oxidized slag inclusions, gas absorption, hot cracks, etc. in the bonding area; there is no obvious interface between the two steels, forming a metallurgical bond. Combine to form puzzles. After testing, the performance of the steel-steel bimetal composite material is good, and the peel strength is 228N/mm.

Example 6

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel, including the following steps:

Step 1. Perform hot-dip galvanizing surface treatment on the solid 304 stainless steel preset material to be connected, and the thickness of the zinc layer is 50 μm;

Step 2, presetting the surface-treated solid 304 stainless steel at the required position in the mold cavity;

Step 3: Melt 16MnL low-alloy high-strength steel in a resistance furnace and pour it into the mold cavity. Using the processing technology of squeeze casting, the pouring temperature is 1800 ° C, and the squeeze casting pressure is 70 MPa to form a metallurgical bond between the steel and the steel. Combine;

Step 4: Perform annealing treatment on the obtained 304-16MnL steel bimetallic rolling billet before rolling, the annealing temperature is 100°C, the time is 100min, then continue the hot rolling processing, the reduction rate is 40%, the rolling temperature 100℃, rolling speed 10m/s;

Step 5. Put the obtained steel-steel bimetallic composite material into an annealing furnace for post-rolling annealing treatment. The annealing temperature is 400° C. and the annealing time is 5 minutes.

After testing, it is found that there are no defects such as oxidized slag inclusions, gas absorption, hot cracks, etc. in the bonding area; there is no obvious interface between the two steels, forming a metallurgical bond. Combine to form puzzles. After testing, the performance of the steel-steel bimetal composite material is good, and the peel strength is 230N/mm.

Comparative example 1

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel. The technical solution is the same as that of Embodiment 1, except that the thickness of the galvanized layer is 80 μm.

After testing, it was found that defects such as oxidized slag inclusions, pores, and hot cracks appeared in the bonding area. No metallurgical bond can be formed between the two materials, no continuous and uniform intermetallic compound is formed in the interface area, and zinc elements gather at the interface, and obvious cracks appear on the interface. After testing, the mechanical properties of the steel-aluminum bimetal composite are poor, and the peel strength is less than 10N/mm.

Comparative example 2

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel. The technical solution is the same as that of embodiment 1, except that the rolling process is not performed after solid-liquid compound casting.

After testing, it was found that there were no defects such as oxidized slag inclusions, pores, and thermal cracks in the bonding area. A metallurgical bond is formed between the two materials, and intermetallic compounds are continuously distributed in the interface area, indicating that a metallurgical bond is formed between the two metals, but a hard and thick intermediate compound is formed between the two metals, which seriously affects the connection performance. After testing, the mechanical properties of the steel-aluminum bimetal composite are poor, and the peel strength is 18N/mm.

Comparative example 3

This embodiment relates to a method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel. The technical solution is the same as that of embodiment 1, except that the rolling blank is a steel material that has not been connected by solid-liquid compound casting and Magnesium material, mechanically put together for rolling process.

After testing, it was found that there were no defects such as oxidized slag inclusions, pores, and thermal cracks in the bonding area. A metallurgical bond is formed between the two materials, and there is an intermetallic compound in the interface area, indicating that a metallurgical bond is formed between the two metals, but the intermetallic compound is not continuous, and there is an oxide scale between the two metals, which is precisely due to the presence of the oxide scale The formation of a continuous intermetallic compound between the two metals is affected, resulting in poorer connection performance and conductivity than in Example 1. After testing, the mechanical properties of the steel-aluminum bimetal composite are poor, and the peel strength is 10N/mm.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (10)

1. A method for preparing bimetallic composite materials through solid-liquid compounding and rolling combination of solid steel, characterized in that, the method comprises the step of preparing bimetallic rolling blanks by solid-liquid composite casting, rolling the blanks to prepare bimetallic composites Composite steps. 2. the method for preparing bimetallic composite materials by solid-liquid composite and rolling combination of solid steel according to claim 1, is characterized in that, the step of preparing bimetallic rolling stock by solid-liquid composite casting specifically comprises: Treatment preset: Surface treatment is carried out on the solid copper preset material to be connected, and it is preset in the mold cavity after treatment; Casting combination: pouring the liquid material to be poured into the cavity of the mold, and casting to form a bimetal rolling billet. 3 . The method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel according to claim 2 , wherein the pouring material includes a metal or alloy having a melting point lower than or equal to that of the solid steel material. 4 . 4. The method for preparing a bimetallic composite material by combining solid-liquid compounding and rolling of solid steel according to claim 2, characterized in that, in the step of pre-processing, the surface treatment specifically refers to a galvanized protective layer. 5. The method for preparing bimetallic composite materials by combining solid-liquid compounding and rolling of solid steel according to claim 2, is characterized in that, in the step of casting combination, the method of casting includes sand casting, metal mold casting, low-pressure casting Casting, high pressure casting, vacuum casting, squeeze casting or centrifugal casting; the pouring temperature is 450-1800°C. 6. the method for preparing bimetallic composite material according to solid-liquid compounding of solid steel according to claim 1 and rolling combination, it is characterized in that, in the step of rolling described billet preparation bimetallic composite material, the mode of described rolling It is double-layer rolling or three-layer rolling; said rolling is cold rolling, warm rolling or hot rolling; The rolling temperature is -100°C to 100°C below the melting point of the casting material; The reduction rate of the rolling is 10-75%, and the rolling speed is 0.01-10m/s. 7. according to claim 1 or 6, solid-liquid compounding of solid steel and rolling combination prepare the method for bimetallic composite material, it is characterized in that, the step of described rolling described billet preparation bimetallic composite material also comprises to gained Bimetallic composites are annealed after rolling. 8. The method for preparing bimetallic composite materials by combining solid-liquid composite and rolling of solid steel according to claim 7, characterized in that, the temperature of the annealing treatment is 100°C to 100°C below the melting point of the casting material, and the time for the annealing treatment is 100°C. 5 to 300 minutes. 9. according to claim 1 or 6, solid-liquid compounding of solid steel and rolling combination prepare the method for bimetallic composite material, it is characterized in that, the step of described rolling described billet preparation bimetallic composite material also comprises to gained Bimetallic rolled billets are annealed before rolling. 10. The method for preparing bimetallic composite materials by combining solid-liquid compounding and rolling of solid steel according to claim 9, characterized in that, the temperature of the annealing treatment is 100°C to 100°C below the melting point of the casting material, and the time of the annealing treatment is 100°C. 0-300min.