Titanium alloy / carbon steel composite plate and preparation method thereof

Abstract

The present invention provides a titanium alloy / carbon steel composite plate and a preparation method thereof, belonging to the technical field of metal composite plate material processing. The present invention grooves the carbon steel plate and corrugates the titanium alloy plate, and the grooves and corrugated teeth are engaged with each other during the assembly, so that the titanium and steel can be effectively deformed in coordination, the titanium layer applies tensile stress to the steel layer, and the steel layer applies compressive stress to the titanium layer; the rough rolling and fine rolling rolling processes are adopted in the rolling process, which can effectively break up the surface metal and the interface impurity layer to form a tightly bonded titanium / steel interface, thereby promoting the formation of the titanium / steel interface; the assembly is sealed and vacuumed, which reduces the oxidation of the metal surface of the rolled titanium / steel composite plate, inhibits the generation of brittle compounds between metals, and reduces the interface residual stress. The titanium alloy / carbon steel composite plate interface obtained by the preparation method provided by the present invention has the characteristics of tight interface bonding and low interface residual stress.

Description

Technical Field

[0001] The invention relates to the technical field of metal composite plate material processing, and in particular to a titanium alloy / carbon steel composite plate and a preparation method thereof. Background Art

[0002] With the continuous development of science and technology, the performance of a single material is increasingly difficult to meet the needs of industrial production. Metal layered composite plates are widely recognized by people because of their high cost-effectiveness, good comprehensive performance, strong adaptability to various complex environments, and the ability to meet performance requirements that a single metal cannot meet. Titanium / steel composite plates have both the excellent corrosion resistance and thermal stability of titanium and the toughness and good weldability of alloy steel. Titanium / steel composite plates are widely used in many fields such as automobiles, petrochemicals, aerospace, marine engineering, and ships.

[0003] The production and preparation technologies of titanium / steel composite plates mainly include explosive composite method, diffusion composite method, rolling composite method, etc. The explosive composite method is a process method that uses the instantaneous high temperature and high pressure environment generated by the explosion of explosives to composite dissimilar metals. The explosive composite method can make dissimilar metals combine well, but it will also produce interface stress concentration, which has a great potential threat to the long-term use of the composite plate. In addition, some components of the explosive will remain on the bonding surface of the titanium-steel composite plate, causing inclusions, crack expansion and cracking or local stress concentration during the use of the titanium / steel composite plate, which will lead to adverse effects such as warping. The advantages of the rolling composite method for producing heterogeneous metal composite plates are: a large product size range, high production efficiency, and suitable for mass production. However, rolling titanium / steel composite plates at high temperatures is a relatively complicated process, because titanium alloys and carbon steels have different deformation resistance at the same temperature, and their thermal properties are quite different. In the rolling process, the titanium alloys and carbon steels will be deformed in an uncoordinated manner. Due to the uncoordinated deformation of titanium alloys and carbon steels, large residual stress is generated at the titanium / steel interface, which not only affects the interface bonding strength of the titanium / steel composite plate, but also causes warping of the titanium / steel composite plate after rolling. In the subsequent forming and use of the plate, excessive residual strain will cause microcracks at the interface, and then crack expansion will cause the deterioration of the interface performance. In summary, the existing production processes of titanium / steel composite plates all have the problem of large residual stress at the bonding interface, which can easily cause crack expansion and cracking or local stress concentration during the use of the titanium / steel composite plate, leading to warping.

[0004] In the actual production process, residual stress is often reduced by heat treatment and natural aging. The commonly used annealing process during heat treatment is generally overall annealing, which is to put the overall composite slab into an annealing furnace for annealing. During the heating process, there is a difference in the internal and external heating time, resulting in problems such as inconsistent bonding strength of the composite plate. Long-term natural aging greatly prolongs the entire processing time, resulting in reduced production efficiency and increased costs.

[0005] Therefore, how to improve production efficiency and further reduce the interface residual stress of titanium alloy / carbon steel composite plates to produce titanium alloy / carbon steel composite plates with tight interface bonding and low interface residual stress has become a technical problem to be solved urgently in this field. Summary of the invention

[0006] The object of the present invention is to provide a titanium alloy / carbon steel composite plate and a preparation method thereof. The titanium alloy / carbon steel composite plate obtained by the preparation method provided by the present invention has a tight interface and low interface residual stress.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a titanium alloy / carbon steel composite plate, comprising the following steps:

[0009] (1) mechanically groove the surface of the carbon steel plate to be composited to obtain a grooved carbon steel plate;

[0010] (2) corrugating the surface of the titanium alloy plate to be composited to obtain a rolled titanium alloy plate;

[0011] (3) placing the composite surfaces of the grooved carbon steel plate obtained in step (1) and the rolled titanium alloy plate obtained in step (2) opposite to each other for assembling to obtain a composite blank;

[0012] (4) sealing and evacuating the composite blank obtained in step (3) in sequence to obtain a blank to be rolled;

[0013] (5) sequentially heating, rough rolling, finish rolling and heat treating the billet to be rolled obtained in step (4) to obtain a titanium alloy / carbon steel composite plate;

[0014] There is no order of precedence between step (1) and step (2);

[0015] The grooves of the grooved carbon steel plate in step (1) and the corrugated teeth of the rolled titanium alloy plate in step (2) engage with each other.

[0016] Preferably, the groove width of the grooved carbon steel plate in step (1) is 6 to 10 mm, and the depth is 2 to 5 mm.

[0017] Preferably, in the step (2), the relationship between the corrugation height s and the corrugation width t of the rolled titanium alloy plate is: t=(1-5)s.

[0018] Preferably, when the titanium alloy / carbon steel composite plate is a "sandwich" structure of carbon steel-titanium alloy-carbon steel, the upper and lower surfaces of the rolled titanium alloy plate are both corrugated surfaces, and the assembly in step (3) includes: placing a grooved carbon steel plate on the upper and lower sides of the rolled titanium alloy plate, respectively, so that the corrugated teeth of the rolled titanium alloy plate and the grooves of the composite surface of the grooved carbon steel plate are engaged with each other and then fixed.

[0019] Preferably, the sealing in step (3) comprises: using four sealing strips to seal and weld the four sides of the composite blank.

[0020] Preferably, the rough rolling in step (4) is performed in two passes, the rolling temperature of the rough rolling is 850-900° C., the reduction ratio of the first pass of the rough rolling is 10-15%, and the reduction ratio of the second pass of the rough rolling is 15-20%.

[0021] Preferably, the finishing rolling in step (4) is performed in two passes, the rolling temperature of the finishing rolling is 850-900° C., the reduction ratio of the first finishing rolling pass is 15-20%, and the reduction ratio of the second finishing rolling pass is 25-30%.

[0022] Preferably, the total reduction ratio of rough rolling and finish rolling in step (4) is 65-85%.

[0023] Preferably, the heat treatment temperature in step (4) is 500-650° C., and the heat treatment time is 1.5-2.5 h.

[0024] The present invention also provides a titanium alloy / carbon steel composite plate prepared by the preparation method described in the above technical solution.

[0025] The present invention provides a method for preparing a titanium alloy / carbon steel composite plate, comprising the following steps: (1) mechanically notching a surface of a carbon steel plate to be composited to obtain a notched carbon steel plate; (2) corrugating the surface of the titanium alloy plate to be composited to obtain a rolled titanium alloy plate; (3) placing the notched carbon steel plate obtained in step (1) and the composite surface of the rolled titanium alloy plate obtained in step (2) relative to each other for assembly to obtain a composite blank; (4) sealing and evacuating the composite blank obtained in step (3) in turn to obtain a blank to be rolled; (5) heating, rough rolling, finish rolling and heat treatment the blank to be rolled obtained in step (4) in turn to obtain a titanium alloy / carbon steel composite plate; there is no order between step (1) and step (2); the notches of the notched carbon steel plate in step (1) and the corrugated teeth of the rolled titanium alloy plate in step (2) are engaged with each other. The present invention grooves the carbon steel plate and corrugates the titanium alloy plate, and the grooves and corrugated teeth are engaged with each other during the assembly, so that the titanium and steel can be effectively deformed in coordination, the titanium layer applies tensile stress to the steel layer, and the steel layer applies compressive stress to the titanium layer; the rough rolling and fine rolling rolling processes are adopted in the rolling process, which can effectively break the surface metal and the interface impurity layer to form a tightly bonded titanium / steel interface, thereby promoting the formation of the titanium / steel interface; the assembly is sealed and vacuumed, which reduces the oxidation of the metal surface of the rolled titanium / steel composite plate, inhibits the generation of brittle compounds between metals, and reduces the interface residual stress. The results of the embodiment show that the interface bonding rate of the titanium alloy / carbon steel composite plate obtained by the preparation method provided by the present invention reaches 100%, the shear strength is 336-352MPa, and the residual stress at the interface of the composite plate is 23-31MPa, which has the characteristics of tight interface bonding and low interface residual stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the shape of the grooved carbon steel plate in Example 1 of the present invention;

[0027] Figure 2 Schematic diagram of the shape of the rolled titanium alloy plate in Example 1 of the present invention; wherein s is the corrugation height of the titanium alloy plate after rolling, t is the corrugation width, and h is the thickness of the titanium alloy plate after rolling excluding the corrugation height;

[0028] Figure 3 This is a schematic diagram of assembling a carbon steel plate and a titanium alloy plate in Example 1 of the present invention;

[0029] Figure 4 This is a schematic diagram of rough rolling of a titanium alloy / carbon steel composite plate in Example 1 of the present invention;

[0030] Figure 5 This is a schematic diagram of the finish rolling of the titanium alloy / carbon steel composite plate in Example 1 of the present invention;

[0031] Figure 6Schematic diagram of the structure of the titanium alloy / carbon steel composite plate obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The present invention provides a method for preparing a titanium alloy / carbon steel composite plate, comprising the following steps:

[0033] (1) mechanically groove the surface of the carbon steel plate to be composited to obtain a grooved carbon steel plate;

[0034] (2) corrugating the surface of the titanium alloy plate to be composited to obtain a rolled titanium alloy plate;

[0035] (3) placing the composite surfaces of the grooved carbon steel plate obtained in step (1) and the rolled titanium alloy plate obtained in step (2) opposite to each other for assembling to obtain a composite blank;

[0036] (4) sealing and evacuating the composite blank obtained in step (3) in sequence to obtain a blank to be rolled;

[0037] (5) sequentially heating, rough rolling, finish rolling and heat treating the billet to be rolled obtained in step (4) to obtain a titanium alloy / carbon steel composite plate;

[0038] There is no order of precedence between step (1) and step (2);

[0039] The grooves of the grooved carbon steel plate in step (1) and the corrugated teeth of the rolled titanium alloy plate in step (2) engage with each other.

[0040] The present invention mechanically grooves the surface to be composited of the carbon steel plate to obtain the grooved carbon steel plate.

[0041] In the present invention, the material of the carbon steel plate is preferably one of Q215, Q235, Q345 and Q355; the thickness of the carbon steel plate is preferably 10 to 30 mm, more preferably 20 to 30 mm. The present invention limits the material and size of the carbon steel plate to the above range to ensure smooth feeding.

[0042] In the present invention, the width of the groove of the grooved carbon steel plate is preferably 6-10 mm, more preferably 7-9 mm, and further preferably 8 mm; the depth of the groove of the grooved carbon steel plate is preferably 2-5 mm, and more preferably 3-4 mm. In the present invention, setting the groove parameters of the grooved carbon steel plate within the above range can facilitate the subsequent composite with the titanium alloy plate.

[0043] The present invention preferably pre-treats the surface to be composited of the carbon steel plate before mechanical grooving.

[0044] In the present invention, the process of pre-treating the surface to be composited of the carbon steel plate preferably includes grinding and cleaning.

[0045] In the present invention, the grinding is preferably to remove the oxide layer on the surface of the carbon steel plate substrate by a grinding wheel or a wire brush, and then to grind with fine sandpaper until the roughness of the surface to be composited is less than 2 μm. The present invention can expose fresh metal by grinding, and ensure that the surface is flat and smooth, which is conducive to the subsequent composite board composite.

[0046] In the present invention, the cleaning is preferably carried out by using acetone and alcohol in sequence or by using acetone, acid solution and alcohol in sequence. The present invention has no special restrictions on the cleaning operation and the concentration of the solvent, and the surface to be composited of the carbon steel plate substrate can be cleaned by using cleaning steps well known to those skilled in the art.

[0047] The present invention performs corrugation rolling on the surface to be composited of the titanium alloy plate to obtain a rolled titanium alloy plate.

[0048] In the present invention, the material of the titanium alloy plate is preferably one of TA1, TA2 and TC4; the thickness of the titanium alloy plate is preferably 10 to 30 mm, more preferably 10 to 16 mm. The present invention limits the material and size of the titanium alloy plate to the above range to ensure smooth feeding.

[0049] In the present invention, the cross-sectional shape of the corrugation of the rolled titanium alloy plate is preferably an arc, an ellipse, a sine wave, a triangle, a trapezoid or a rectangle. In the present invention, the corrugation rolling is preferably carried out in a double-roll mill; the double rolls of the double-roll mill are preferably corrugated rolls, and the lines are symmetrically distributed; the reduction rate of the corrugation rolling is preferably not less than 35%; the corrugation rolling speed is preferably 20 to 40 r / min.

[0050] In the present invention, the relationship between the corrugation height s and the corrugation width t of the rolled titanium alloy plate is preferably: t = (1 ~ 5) s, more preferably t = (2 ~ 4) s, and further preferably t = 3s. In the present invention, the relationship between the thickness h and s of the rolled titanium alloy plate excluding the corrugation height is preferably s / h = (0.1 ~ 0.8), more preferably s / h = (0.3 ~ 0.5), and further preferably s / h = 0.4. In the present invention, the minimum height of the corrugation is preferably greater than 10% of the thickness h of the rolled composite plate, and more preferably greater than 40% of the thickness h of the rolled composite plate. In the present invention, the bending angle of the rolled titanium alloy plate is preferably not more than 15°, and more preferably not more than 13°. The present invention limits the corrugation size of the rolled titanium alloy plate to the above range so that it can be better compounded with the carbon steel plate.

[0051] The present invention preferably pre-treats the surface to be composited of the titanium alloy plate before corrugation rolling.

[0052] The process of pre-treating the surface to be composited of the titanium alloy plate of the present invention is the same as the process of pre-treating the surface to be composited of the carbon steel plate, which will not be described in detail here.

[0053] After obtaining the grooved carbon steel plate and the rolled titanium alloy plate, the composite surfaces of the grooved carbon steel plate and the rolled titanium alloy plate are placed opposite to each other for blanking to obtain a composite blank.

[0054] In the present invention, when the titanium alloy / carbon steel composite plate is a "sandwich" structure of carbon steel-titanium alloy-carbon steel, the upper and lower surfaces of the rolled titanium alloy plate are preferably both corrugated surfaces.

[0055] In the present invention, the assembling preferably includes: placing a grooved carbon steel plate above and below the rolled titanium alloy plate respectively, so that the corrugated teeth of the rolled titanium alloy plate and the grooves of the grooved carbon steel plate are engaged with each other and then fixed.

[0056] In the present invention, the fixing is preferably electron beam spot welding.

[0057] After obtaining the composite blank, the present invention sequentially seals and vacuumizes the composite blank to obtain the blank to be rolled.

[0058] In the present invention, the sealing preferably includes: using four sealing strips to seal and weld the four sides of the blank.

[0059] In the present invention, the width of the seal is preferably the thickness of the symmetrical blank; the material of the seal is preferably carbon steel. The present invention limits the width and material of the seal to the above range, which is more conducive to welding and forming a sealed blank.

[0060] In the present invention, the vacuuming preferably includes: drilling a through hole in the seal, welding the carbon steel pipe to the seal, and after vacuuming by a vacuum device, flattening the carbon steel pipe to seal it.

[0061] The present invention has no special limitation on the position of the through hole, as long as the pores in the composite slab can be connected to the outside.

[0062] In the present invention, the vacuum degree of the vacuum pumping is preferably 10 -3 Pa; the flattening seal is preferably achieved by heating the carbon steel pipe to 800-1100°C with a welding torch, flattening it with hydraulic pliers, removing excess parts, and then sealing it with vacuum mud.

[0063] The present invention can reduce oxidation of the metal surface of the rolled titanium / steel composite plate by vacuuming, inhibit the generation of brittle compounds between metals, and reduce interface residual stress.

[0064] After the blank to be rolled is obtained, the present invention sequentially heats, roughly rolls, finish rolls and heat treats the blank to be rolled to obtain a titanium alloy / carbon steel composite plate.

[0065] In the present invention, the heating is preferably vacuum heating; the heating temperature is preferably 600-800°C, more preferably 700°C; the heating time is ≥1h, more preferably 1-2h. The present invention has no special limitation on the vacuum heating equipment, and the vacuum heating equipment commonly used by those skilled in the art can be used. The present invention limits the heating temperature and time to the above ranges so that the billet to be rolled can be softened, which is more conducive to the subsequent rolling.

[0066] In the present invention, the rough rolling is preferably performed in two passes; the rolling temperature of the rough rolling is preferably 850-900°C, more preferably 880°C; the first pass reduction rate of the rough rolling is preferably 10-15%, more preferably 13%; the first pass rolling speed of the rough rolling is preferably 30-35r / min, more preferably 30r / min; the second pass reduction rate of the rough rolling is preferably 15-20%, more preferably 18%; the second pass rolling speed of the rough rolling is preferably 30-35r / min, more preferably 35r / min. The equipment used for the rough rolling is preferably a flat roll mill.

[0067] In the present invention, it is preferred to introduce protective gas into the rolling channel in advance before rough rolling. When the oxygen content in the rolling channel is lower than 1%, the vacuum heating furnace is turned on, and protective gas is continuously introduced at the entrance of the vacuum heating furnace, and the billet is pushed into the flat rolling mill for rough rolling. In the present invention, the protective gas is preferably argon.

[0068] In the present invention, the finishing rolling is preferably 2 passes; the rolling temperature of the finishing rolling is preferably 850-900°C, more preferably 880°C; the first pass reduction rate of the finishing rolling is preferably 15-20%, more preferably 18%; the first pass rolling speed of the finishing rolling is preferably 30-35r / min, more preferably 35r / min; the second pass reduction rate of the finishing rolling is preferably 25-30%, more preferably 28%; the second pass rolling speed of the finishing rolling is preferably 30-40r / min, more preferably 35-40r / min, and further preferably 40r / min. The equipment used for the finishing rolling is preferably a two-roll flat rolling mill.

[0069] The present invention sets the temperature and pass reduction rate of rough rolling and finish rolling within the above range so that the rolling has a large reduction amount, which can effectively break up the surface metal and interface impurity layer, form a tightly bonded titanium / steel interface, and thus promote the formation of the titanium / steel interface.

[0070] In the present invention, the total reduction ratio of the rough rolling and the finish rolling is preferably 65-85%, more preferably 70-80%, and further preferably 75%. The present invention limits the total reduction ratio of the rough rolling and the finish rolling to the above range to promote the formation of the titanium / steel interface and make the interface bond more closely.

[0071] In the present invention, the temperature of the heat treatment is preferably 500-650°C, more preferably 550-600°C; the time of the heat treatment is preferably 1.5-2.5h, more preferably 2h. In the present invention, the cooling method of the heat treatment is preferably furnace cooling. The present invention limits the temperature, time and cooling method of the heat treatment to the above ranges to fully eliminate the residual stress at the interface of the composite plate.

[0072] The present invention grooves the carbon steel plate and corrugates the titanium alloy plate, and makes the grooves and corrugated teeth mesh with each other during assembly, so that the titanium and steel can be effectively deformed in coordination, the titanium layer applies tensile stress to the steel layer, and the steel layer applies compressive stress to the titanium layer; in the rolling process, rough rolling and fine rolling are adopted to effectively break up the surface metal and the interface impurity layer, form a tightly combined titanium / steel interface, and thus promote the formation of the titanium / steel interface; the assembly is sealed and vacuumed, so that the oxidation of the metal surface of the rolled titanium / steel composite plate is reduced, the generation of brittle compounds between metals is suppressed, and the interface residual stress is reduced.

[0073] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0074] Example 1

[0075] A method for preparing a titanium alloy / carbon steel composite plate comprises the following steps:

[0076] (1) The surfaces of two Q345 carbon steel plates with a thickness of 20 mm and a length and width of 1800 mm × 1000 mm to be composited were ground with a grinding wheel and then with 150-2000# sandpaper until they were flat and uniform with a roughness of less than 2 μm. They were then cleaned with acetone and then cleaned with alcohol and mechanically grooved to obtain grooved carbon steel plates (the shape diagram of the grooved carbon steel plates is shown in FIG. Figure 1 The width of the mechanical groove is 6mm and the depth is 3mm;

[0077] (2) The surface to be composited of a TA2 titanium alloy plate with a thickness of 14 mm and a length and width of 1800 mm × 1000 mm was ground with a grinding wheel and then with 150-2000# sandpaper until it was flat and uniform with a roughness of less than 2 μm, and then cleaned with acetone, and then cleaned with alcohol, and corrugated with a toothed double roller to obtain a rolled titanium alloy plate (the shape diagram of the rolled titanium alloy plate is shown in FIG. Figure 2As shown); the cross-sectional shape of the corrugation formed by the corrugation rolling is a trapezoid, and the trapezoidal corrugation is perpendicular to the surface of the TA2 titanium alloy plate; the corrugation height s is 3mm, the corrugation width t is 6mm, and the thickness h of the titanium alloy plate after rolling excluding the corrugation height is 7mm; the bending angle of the rolled titanium alloy plate does not exceed 10°; s / h=0.43, t=2s;

[0078] (3) The grooved carbon steel plate obtained in step (1) and the composite surface of the rolled titanium alloy plate obtained in step (2) are placed opposite to each other for assembly (a schematic diagram of the assembly of the carbon steel plate and the titanium alloy plate is shown in FIG. Figure 3 As shown), a "sandwich" structure of carbon steel-titanium alloy-carbon steel is formed, whereby the corrugated teeth of the rolled titanium alloy plate and the grooves of the composite surface of the grooved carbon steel plate are engaged with each other and then fixed together by electron beam spot welding to obtain a composite blank;

[0079] (4) The composite blank obtained in step (3) is sealed and welded around four sealing strips, and then a through hole is drilled in any one of the four sealing strips, and a carbon steel pipe is welded to the sealing strip. A leak detection device is used to check to ensure that the welding package is intact, and a vacuum device containing a mechanical pump, a magnetic pump and a diffusion pump is used to evacuate the blank to a vacuum degree of 10 -3 Pa, heat the carbon steel pipe to 850℃ with an argon arc welding gun, seal the carbon steel pipe with a hydraulic clamp, cut off the excess part, and finally seal the stainless steel pipe with vacuum mud to obtain the billet to be rolled; the width of the seal is 54.8mm;

[0080] (5) The billet to be rolled obtained in step (4) is vacuum heated to 600° C. and kept warm for 1.5 h. A protective gas is introduced into the rolling channel in advance. When the oxygen content in the rolling channel measured by the oxygen content detector is lower than 1%, the vacuum furnace is turned on, and the protective gas is continuously introduced into the inlet of the vacuum furnace. The billet is quickly pushed into the flat roll mill for rough rolling using a push rod (a schematic diagram of rough rolling of titanium alloy / carbon steel composite plate is shown in FIG. 1 ). Figure 4 As shown), and then finish rolling (the schematic diagram of the finish rolling of titanium alloy / carbon steel composite plate is as shown Figure 5 The rolled titanium alloy / carbon steel composite plate is placed in a heat treatment device and heated to 590°C for 1.6 hours to obtain a titanium alloy / carbon steel composite plate (the structural schematic diagram of the titanium alloy / carbon steel composite plate is shown in FIG. Figure 6The rough rolling is performed in two passes; the rolling temperature of the rough rolling is 890°C; the first pass reduction rate of the rough rolling is 15%; the first pass rolling speed of the rough rolling is 30r / min; the second pass reduction rate of the rough rolling is 20%; the second pass rolling speed of the rough rolling is 30r / min; the finish rolling is performed in two passes; the rolling temperature of the finish rolling is 860°C; the first pass reduction rate of the finish rolling is 20%; the first pass rolling speed of the finish rolling is 30r / min; the second pass reduction rate of the finish rolling is 25%; the second pass rolling speed of the finish rolling is 30r / min;

[0081] There is no order of precedence for step (1) and step (2).

[0082] The titanium-steel composite plate prepared by the preparation method of this embodiment has an interface bonding rate of 100% and a shear strength of 352 MPa. The residual stress at the interface of the composite plate after stress elimination measured by X-ray method is 23 MPa.

[0083] Example 2

[0084] A method for preparing a titanium alloy / carbon steel composite plate comprises the following steps:

[0085] (1) The surfaces to be combined of two Q235 carbon steel plates with a thickness of 25 mm and a length and width of 500 mm × 200 mm were ground with a grinding wheel and then ground with 150-2000# sandpaper until they were flat and uniform with a roughness of less than 2 μm, and then cleaned with acetone, and then cleaned with an acid solution, and finally cleaned with alcohol and mechanically grooved to obtain grooved carbon steel plates; the width of the mechanical groove was 8 mm and the depth was 5 mm;

[0086] (2) The surface to be combined of a TC4 titanium alloy plate with a thickness of 16 mm and a length and width of 500 mm×200 mm was ground with a grinding wheel and then ground with 150-2000# sandpaper until it was flat and uniform with a roughness of less than 2 μm, and then cleaned with acetone, and then cleaned with an acid solution, and finally cleaned with alcohol and corrugated with a toothed double roller to obtain a rolled titanium alloy plate; the corrugated cross-section shape formed by the corrugated rolling was a triangle, and the trapezoidal corrugation was perpendicular to the surface of the TA4 titanium alloy plate; the corrugation height s was 4.5 mm, the corrugation width t was 8 mm, and the thickness h of the rolled titanium alloy plate excluding the corrugation height was 8 mm; the bending angle of the rolled titanium alloy plate did not exceed 13°; s / h=0.56, t=1.8s;

[0087] (3) placing the grooved carbon steel plate obtained in step (1) and the composite surface of the rolled titanium alloy plate obtained in step (2) opposite to each other for assembly to form a "sandwich" structure of carbon steel-titanium alloy-carbon steel, so that the corrugated teeth of the rolled titanium alloy plate and the grooves of the composite surface of the grooved carbon steel plate are engaged with each other and then fixed together by electron beam spot welding to obtain a composite blank;

[0088] (4) The composite blank obtained in step (3) is sealed and welded around four sealing strips, and then a through hole is drilled in any one of the four sealing strips, and a carbon steel pipe is welded to the sealing strip. A leak detection device is used to check to ensure that the welding package is intact, and a vacuum device containing a mechanical pump, a magnetic pump and a diffusion pump is used to evacuate the blank to a vacuum degree of 10 -3 Pa, heat the carbon steel pipe to 880℃ with an argon arc welding gun, seal the carbon steel pipe with a hydraulic clamp, cut off the excess part, and finally seal the stainless steel pipe with vacuum mud to obtain the billet to be rolled; the width of the seal is 71mm;

[0089] (5) vacuum heating the billet to be rolled obtained in step (4) to 750° C., keeping the temperature for 1.2 h, introducing protective gas into the rolling channel in advance, and when the oxygen content in the rolling channel measured by the oxygen content detector is lower than 1%, opening the vacuum furnace, continuously introducing protective gas into the entrance of the vacuum furnace, and using a push rod to quickly push the billet into the flat roll mill for rough rolling, and then performing finish rolling, placing the rolled titanium alloy / carbon steel composite plate into a heat treatment device and heating it to 550° C., keeping the temperature for 1.5 h, to obtain a titanium alloy / carbon steel composite plate; the rough rolling is performed in two passes; the rough rolling is performed in two passes. The rolling temperature is 900℃; the first pass reduction rate of the rough rolling is 10%; the first pass rolling speed of the rough rolling is 30r / min; the second pass reduction rate of the rough rolling is preferably 20%; the second pass rolling speed of the rough rolling is 35r / min; the finishing rolling is 2 passes; the rolling temperature of the finishing rolling is 870℃; the first pass reduction rate of the finishing rolling is 20%; the first pass rolling speed of the finishing rolling is 35r / min; the second pass reduction rate of the finishing rolling is 25%; the second pass rolling speed of the finishing rolling is 40r / min;

[0090] There is no order of precedence for step (1) and step (2).

[0091] The shear strength of the titanium alloy / carbon steel composite plate obtained by the preparation method of this embodiment reaches 336 MPa. The residual stress at the interface of the composite plate after stress relief measured by X-ray method is 31 MPa, and the titanium alloy / carbon steel composite plate does not experience obvious warping.

[0092] The titanium alloy / carbon steel composite plate prepared by the preparation method of the present invention has a bonding rate of 100%, a shear strength of 336-352 MPa, and a residual stress at the interface of the composite plate of 23-31 MPa. It has the characteristics of tight interface bonding and low interface residual stress, and provides a feasible method for industrially realizing the production of low residual stress titanium alloy / carbon steel composite plates.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a titanium alloy / carbon steel composite plate, comprising the following steps: (1) mechanically groove the surface of the carbon steel plate to be composited to obtain a grooved carbon steel plate; (2) corrugating the surface of the titanium alloy plate to be composited to obtain a rolled titanium alloy plate; (3) placing the grooved carbon steel plate obtained in step (1) and the rolled titanium alloy plate obtained in step (2) with their surfaces to be composited facing each other for assembling to obtain a composite blank; (4) sealing and evacuating the composite blank obtained in step (3) in sequence to obtain a blank to be rolled; (5) sequentially heating, rough rolling, finish rolling and heat treating the billet to be rolled obtained in step (4) to obtain a titanium alloy / carbon steel composite plate; There is no order of precedence between step (1) and step (2); The grooves of the grooved carbon steel plate in step (1) and the corrugated teeth of the rolled titanium alloy plate in step (2) are engaged with each other; In the step (1), the groove width of the grooved carbon steel plate is 6 to 10 mm, and the depth is 2 to 5 mm; The relationship between the corrugation height s and the corrugation width t of the rolled titanium alloy plate in step (2) is: t = (1 to 5) s; The rough rolling in step (5) is performed in two passes, the rolling temperature of the rough rolling is 850-900°C, the first pass reduction rate of the rough rolling is 10-15%, and the second pass reduction rate of the rough rolling is 15-20%; the finishing rolling in step (5) is performed in two passes, the rolling temperature of the finishing rolling is 850-900°C, the first pass reduction rate of the finishing rolling is 15-20%, and the second pass reduction rate of the finishing rolling is 25-30%; the total reduction rate of the rough rolling and the finishing rolling in step (5) is 65-85%; the temperature of the heat treatment in step (5) is 500-650°C, and the heat treatment time is 1.5-2.5h.

2. The preparation method according to claim 1, characterized in that: When the titanium alloy / carbon steel composite plate is a "sandwich" structure of carbon steel-titanium alloy-carbon steel, the upper and lower surfaces of the rolled titanium alloy plate are both corrugated surfaces, and the assembly of the step (3) includes: placing a grooved carbon steel plate on the upper and lower sides of the rolled titanium alloy plate respectively, so that the corrugated teeth of the rolled titanium alloy plate and the grooves of the grooved carbon steel plate are engaged with each other and then fixed.

3. The preparation method according to claim 1 or 2, characterized in that: The sealing in step (4) includes: using four sealing strips to seal and weld the four sides of the composite blank.

4. The titanium alloy / carbon steel composite plate prepared by the preparation method according to any one of claims 1 to 3.

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