A thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity, its preparation method and application

Abstract

This invention discloses a thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity, its preparation method, and its application, belonging to the field of metal layered composite material technology. The composite plate comprises a steel layer, an intermediate aluminum alloy layer, and a surface aluminum alloy layer; the steel layer, intermediate aluminum alloy layer, and surface aluminum alloy layer are formed from Q235B steel plate, AL6082 aluminum alloy plate, and AL5083 aluminum alloy plate, respectively; the interface between the steel layer and the intermediate aluminum alloy layer has a corrugated structure; the pull-out strength of the composite plate after simulated welding heat input treatment under conditions T1 and T2 is E1 and E2, respectively, while the pull-out strength before simulated welding heat input treatment is E0; T2 > T1, E2 > E1 > E0. This composite plate exhibits positive temperature sensitivity under simulated welding heat input conditions, effectively solving the problem of significant decrease in steel / aluminum bond strength in traditional steel-aluminum composite plates under welding heat input, and improving the load-bearing capacity and service life of the welded joint.

Description

Technical Field

[0001] This invention relates to the field of metal layered composite materials technology, and more specifically, to a thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity, its preparation method and application. Background Technology

[0002] In equipment used in shipbuilding, rail transportation, and cryogenic engineering, reliable connections between steel and aluminum alloy structures are frequently required. Direct fusion welding easily generates brittle Fe-Al intermetallic compounds, leading to joint failure. Currently, steel-aluminum composite plates are widely used in engineering as transition joints, indirectly achieving steel-aluminum connections by welding the steel side to steel and the aluminum side to aluminum.

[0003] Traditional steel-aluminum transition joints are mostly manufactured using an explosive bonding process, with a typical structure consisting of a three-layer composite plate of Q235B (steel), AL 1060 industrial pure aluminum, and AL5083 (aluminum-magnesium alloy). However, extensive engineering practice and testing have shown that when this explosively bonded plate is used as a transition joint and subjected to welding heat input, its interface temperature often reaches 350℃~450℃. Within this temperature range, the steel / aluminum bond strength decreases significantly, severely affecting the joint's load-bearing capacity and service life.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity, its preparation method and application, so as to solve or improve the above-mentioned technical problems.

[0006] This invention can be implemented as follows: In a first aspect, the present invention provides a thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity, the thick steel-aluminum corrugated rolled composite plate comprising a steel layer, an intermediate aluminum alloy layer and a surface aluminum alloy layer stacked sequentially. The steel layer is made of Q235B steel plate, the intermediate aluminum alloy layer is made of AL6082 aluminum alloy plate, and the surface aluminum alloy layer is made of AL5083 aluminum alloy plate; the interface between the steel layer and the intermediate aluminum alloy layer has a corrugated structure. The pull-out strength of the thick steel-aluminum corrugated rolled composite plate after simulated welding heat input treatment time t at temperature T1 is E1; the pull-out strength of the thick steel-aluminum corrugated rolled composite plate after simulated welding heat input treatment time t at temperature T2 is E2; and the pull-out strength of the thick steel-aluminum corrugated rolled composite plate before simulated welding heat input treatment is E0; T2>T1, E2>E1>E0.

[0007] In an optional implementation, the thickness of the thick steel-aluminum corrugated rolled composite plate is 23mm to 26mm. And / or, the thickness of Q235B steel plate is 12mm~20mm; And / or, the thickness of the AL6082 aluminum alloy sheet is 2mm~4mm; And / or, the thickness of the surface aluminum alloy layer is 20mm~29mm.

[0008] In an optional implementation, the wave height in the corrugated structure is 0.2mm~0.3mm and the wave pitch is 1mm~2mm.

[0009] In an optional implementation, 450℃≥T2>T1≥350℃; And / or, t is 25min~35min.

[0010] In an optional implementation, E2 ≥ 1.5E0.

[0011] Secondly, the present invention provides a method for preparing a thick steel-aluminum corrugated rolled composite plate as described in any of the foregoing embodiments, comprising the following steps: S1: After stacking Q235B steel plate and heated AL6082 aluminum alloy plate, corrugated rolling is performed to obtain a Q235B / AL6082 intermediate plate with a corrugated interface. S2: The Q235B / AL6082 intermediate plate and the AL5083 aluminum alloy plate are stacked and heated before being rolled by flat rolls to obtain a thick steel-aluminum corrugated composite plate.

[0012] In an optional implementation, process S1 includes at least one of the following features: Feature 1: AL6082 aluminum alloy sheet is heated at 590℃~610℃ for 0.5h~1h, and then corrugated rolled with Q235B steel sheet at room temperature; Feature 2: The two-roll mill used for corrugated rolling includes corrugated rolls and flat rolls, which correspond to AL6082 aluminum alloy plates and Q235B steel plates, respectively. Feature 3: The reduction of corrugated rolling is 20%~30%, and the rolling speed is 40mm / s~60mm / s.

[0013] In an optional implementation, the S2 process includes at least one of the following features: Feature 4: The AL5083 aluminum alloy sheet is in contact with the AL6082 side of the Q235B / AL6082 intermediate plate; Feature 5: Q235B / AL6082 intermediate plate and AL5083 aluminum alloy plate are stacked and heated at 490℃~510℃ for 0.5h~1h before being rolled by flat rolls; Feature 6: The reduction of the flat roll is 30%~40%, and the rolling speed is 40mm / s~60mm / s.

[0014] Thirdly, the present invention provides an application of a thick steel-aluminum corrugated rolled composite plate according to any of the foregoing embodiments in a steel-aluminum transition joint.

[0015] Fourthly, the present invention provides an apparatus comprising a thick steel-aluminum corrugated rolled composite plate according to any of the foregoing embodiments.

[0016] The beneficial effects of this invention include: The thick steel-aluminum corrugated rolled composite plate provided by this invention exhibits increased pull-out strength with increasing temperature after simulated welding heat input. It can resist or reverse the strength decay under welding heat cycle, effectively solving the problem of significant decrease in steel / aluminum bonding strength in traditional steel-aluminum composite plates under welding heat input. This improves the load-bearing capacity and service life of welded joints and has significant engineering implications for improving the reliability and safety of steel-aluminum transition joints. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the rolling process of the thick steel-aluminum corrugated rolled composite plate provided by the present invention; Figure 2 A comparison of the pull-out strength of the composite plates of Example 1 and Comparative Examples 1-3 in Experiment 1. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0020] The following is a detailed description of the thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity provided by the present invention, its preparation method and application.

[0021] The present invention provides a thick steel-aluminum corrugated rolled composite plate with positive temperature sensitivity, the thick steel-aluminum corrugated rolled composite plate comprising a steel layer, an intermediate aluminum alloy layer and a surface aluminum alloy layer stacked in sequence.

[0022] The steel layer is formed of Q235B steel plate, and the thickness of the Q235B steel plate can be 12mm~20mm, such as 12mm, 15mm, 18mm or 20mm, or other values ​​within the range of 12mm~20mm.

[0023] The intermediate aluminum alloy layer is formed of AL6082 aluminum alloy sheet. The thickness of the AL6082 aluminum alloy sheet can be 2mm to 4mm, such as 2mm, 2.5mm, 3mm, 3.5mm or 4mm, or other values ​​within the range of 2mm to 4mm.

[0024] The surface aluminum alloy layer is formed from AL5083 aluminum alloy sheet. The thickness of the surface aluminum alloy layer can be 20mm~29mm, such as 20mm, 22mm, 25mm, 28mm or 29mm, or other values ​​within the range of 20mm~29mm.

[0025] The thickness of the Q235B steel plate, the thickness of the AL6082 aluminum alloy plate, and the thickness of the surface aluminum alloy layer mentioned above all refer to the thickness of the raw material plate used before rolling.

[0026] It should be noted that the aluminum alloy grade used in the aforementioned intermediate aluminum alloy layer has a decisive influence on the thermal stability of the composite plate. When the intermediate layer is made of AL1060, AL6061, or AL6063 aluminum alloy and the composite plate is prepared using the same process described in this invention, the pull-out strength of the resulting composite plate decreases after simulated heat inputs at T1 and T2 compared to the plate without heat input. Only when AL6082 is used as the intermediate layer in this application does the resulting composite plate exhibit a positive temperature sensitivity, with the pull-out strength increasing with the increase of the heat input temperature. The reason for this may be that during the specific corrugated rolling and hot working process of this invention, the Mg and Si elements contained in the 6082 aluminum alloy form a unique interfacial strengthening structure during interfacial diffusion, solid solution, and reprecipitation. This structure is further strengthened by aging under subsequent heating, pinning the interface and resulting in an abnormally high bonding strength.

[0027] In this invention, the interface between the steel layer and the intermediate aluminum alloy layer has a corrugated structure.

[0028] In some alternative implementations, the above-described corrugated structure has a periodic waveform, which may exemplarily be an arch shape.

[0029] In some optional implementations, the wave height in the corrugated structure can be 0.2mm to 0.3mm, such as 0.2mm, 0.25mm, or 0.3mm, or other values ​​within the range of 0.2mm to 0.3mm. The wave pitch can be 1mm to 2mm, such as 1mm, 1.5mm, or 2mm, or other values ​​within the range of 1mm to 2mm. The term "wave height" refers to the distance between the highest and lowest points of a single waveform; "wave pitch" refers to the distance between two adjacent waveforms.

[0030] It should be noted that the aforementioned corrugated structure can increase the interfacial contact area and achieve mechanical interlocking and metallurgical bonding. Specifically, the wave height affects the depth of mechanical interlocking and the degree of local deformation. If the wave height is too low, the interface undulations are not obvious, the mechanical interlocking effect is weak, and it is difficult to effectively improve the bonding area and shear resistance. If the wave height is too high, the local deformation during corrugated rolling is too large, easily leading to microcracks, excessively thick brittle intermetallic compound layers, or residual stress concentration at the wave crests or troughs, thus reducing the interfacial bonding strength. The wave pitch affects the distribution density and stress uniformity of the interfacial corrugations. If the wave pitch is too short, the spacing between adjacent corrugations is too small, limiting the metal flow space during rolling, easily causing folding, unwelded defects, or stress superposition, which is not conducive to forming a continuous and dense metallurgical bond. If the wave pitch is too long, the corrugation distribution is sparse, the increase in interfacial contact area is limited, the mechanical interlocking effect is weakened, the improvement in bonding strength is not significant, and it is difficult to fully utilize the advantages of the corrugated structure.

[0031] In some optional embodiments, the thickness of the thick steel-aluminum corrugated rolled composite plate can be 23mm to 26mm, such as 23mm, 24mm, 25mm, or 26mm, or other values ​​within the range of 23mm to 26mm. In some more typical embodiments, the thickness of the thick steel-aluminum corrugated rolled composite plate can be 24mm to 25mm.

[0032] In this invention, the pull-out strength of the thick steel-aluminum corrugated rolled composite plate after simulated welding heat input treatment time t at temperature T1 is E1; the pull-out strength of the thick steel-aluminum corrugated rolled composite plate after simulated welding heat input treatment time t at temperature T2 is E2; and the pull-out strength of the thick steel-aluminum corrugated rolled composite plate before simulated welding heat input treatment is E0; T2 > T1, E2 > E1 > E0.

[0033] In other words, the composite plate exhibits positive temperature sensitivity under simulated welding heat input conditions, meaning that the pull-out strength increases with increasing temperature under simulated welding heat input conditions.

[0034] In some alternative implementations, 450℃≥T2>T1≥350℃. That is, T1 and T2 can be any value within the range of 350℃~450℃, such as 350℃, 380℃, 400℃, 420℃ or 450℃, provided that T2>T1.

[0035] In some alternative implementations, t can be 25 min to 35 min, such as 25 min, 30 min or 35 min, or other values ​​within the range of 25 min to 35 min.

[0036] In some alternative implementations, E2 ≥ 1.5E0.

[0037] In some optional implementations, E0 is 112MPa~116MPa, such as 112.3MPa~115.8MPa.

[0038] In some optional implementations, E1 is not less than 150 MPa, such as 152.1 MPa to 156.2 MPa.

[0039] In some optional implementations, E2 is not less than 170 MPa, such as 171.5 MPa to 175.3 MPa.

[0040] As mentioned above, the pull-out strength of the thick steel-aluminum corrugated rolled composite plate provided by this invention increases with the increase of temperature after simulated welding heat input. It can resist or reverse the strength decay under welding thermal cycle, which can significantly improve the thermal service reliability of the transition joint. It has important engineering significance for improving the reliability and safety of steel-aluminum transition joints.

[0041] Accordingly, this invention provides a method for preparing the above-mentioned thick steel-aluminum corrugated rolled composite plate. Please refer to [link to method]. Figure 1 This includes the following steps: S1: After stacking Q235B steel plate and heated AL6082 aluminum alloy plate, corrugated rolling is performed to obtain a Q235B / AL6082 intermediate plate with a corrugated interface.

[0042] In some alternative embodiments, the AL6082 aluminum alloy sheet is heated at 590℃~610℃ (e.g., 590℃, 600℃, or 610℃) for 0.5h~1h, and then corrugated rolled with Q235B steel sheet at room temperature. The heating process can be carried out in a box-type resistance furnace.

[0043] In some alternative embodiments, the two-roll mill used for corrugated rolling includes corrugated rolls and flat rolls, which correspond to AL6082 aluminum alloy plates and Q235B steel plates, respectively.

[0044] In some alternative embodiments, the reduction in corrugated rolling can be 20% to 30%, such as 20%, 22%, 25%, 28%, or 30%, or other values ​​within the range of 20% to 30%. The rolling speed can be 40 mm / s to 60 mm / s, such as 40 mm / s, 45 mm / s, 50 mm / s, 55 mm / s, or 60 mm / s, or other values ​​within the range of 40 mm / s to 60 mm / s.

[0045] If the reduction in corrugated rolling is too small, the corrugated interface will not be able to form sufficient wave height and depth, resulting in weak mechanical interlocking. At the same time, the atoms at the interface cannot achieve sufficient diffusion and bonding, which can easily lead to low overall bonding strength of the composite plate, and even delamination during subsequent flat rolling or use. If the reduction in corrugated rolling is too large, the aluminum alloy layer will undergo excessive lateral extension, resulting in severe local thinning and even microcracks. At the same time, the severe deformation will generate a large amount of deformation heat, which will promote the rapid growth of Fe-Al intermetallic compounds at the interface, forming a brittle layer, which will seriously weaken the bonding performance. If the rolling speed of corrugated rolling is too slow, the aluminum alloy plate will experience a significant temperature drop due to prolonged contact with the rolls and air during the rolling deformation process. This will reduce the material's plasticity and increase its deformation resistance, making it difficult to form a regular corrugated interface and potentially leading to poor interface bonding or localized non-welding. If the rolling speed of corrugated rolling is too fast, the metal will not have enough time to fully flow and fill the corrugated die cavity, resulting in an incomplete corrugated shape. At the same time, the interface contact time is too short under high-speed deformation, resulting in insufficient atomic diffusion, poor metallurgical bonding, and a tendency to produce surface wrinkles or wave defects, affecting the interface uniformity and stability of the composite plate.

[0046] S2: The Q235B / AL6082 intermediate plate and the AL5083 aluminum alloy plate are stacked and heated before being rolled by flat rolls to obtain a thick steel-aluminum corrugated composite plate.

[0047] In some alternative implementations, the AL5083 aluminum alloy sheet layer contacts the AL6082 side of the Q235B / AL6082 intermediate plate. In practice, steel wire can be used to securely bind the layers together around their perimeter.

[0048] In some optional embodiments, the Q235B / AL6082 intermediate plate and the AL5083 aluminum alloy plate are stacked and heated at 490℃~510℃ (e.g., 490℃, 500℃, or 510℃) for 0.5h~1h before being rolled by flat rolls. The heating process can be carried out in a box-type resistance furnace.

[0049] In some alternative embodiments, the two-roll mill used for flat roll rolling is always flat roll. The reduction in flat roll rolling can be 30% to 40%, such as 30%, 35%, or 40%, or other values ​​within the range of 30% to 40%. The rolling speed can be 40 mm / s to 60 mm / s, such as 40 mm / s, 45 mm / s, 50 mm / s, 55 mm / s, or 60 mm / s, or other values ​​within the range of 40 mm / s to 60 mm / s.

[0050] As mentioned above, the preparation method of the thick steel-aluminum corrugated rolled composite plate provided by the present invention is relatively simple to operate, the process is simple and controllable, and it is suitable for industrial production.

[0051] In addition, the present invention also provides an application of the above-mentioned thick steel-aluminum corrugated rolled composite plate in steel-aluminum transition joints.

[0052] In addition, the present invention also provides an apparatus comprising the aforementioned thick steel-aluminum corrugated rolled composite plate.

[0053] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0054] Example 1 This embodiment provides a thick steel-aluminum corrugated rolled composite plate. See [link / reference] Figure 1 Its preparation method includes: S1: AL6082 aluminum alloy sheet (length × width × thickness 200mm × 100mm × 3mm) is heated to 600℃ in a box-type resistance furnace and held for 1 hour. It is then quickly removed and stacked with a Q235B steel sheet (length × width × thickness 200mm × 100mm × 16mm) at room temperature, and fed into a two-roll mill. The upper roll of the two-roll mill is a corrugated roll (corresponding to the AL6082 aluminum sheet side), and the lower roll is a flat roll (corresponding to the Q235B steel sheet side). The reduction is 20%, and the rolling speed is 60mm / s, resulting in a Q235B / AL6082 intermediate plate with a corrugated interface. The corrugated structure has a wave height of 0.2mm and a wave pitch of 1mm~2mm.

[0055] S2: The AL6082 side of the Q235B / AL6082 intermediate plate is stacked with the AL5083 aluminum alloy plate (length × width × thickness 200mm × 100mm × 20mm) to form a billet, and the stack is secured tightly around the perimeter with steel wire. The billet is placed in a box-type resistance furnace, heated to 500℃ and held for 1 hour. After removal, it is quickly rolled on a two-roll mill with flat rolls, where both the upper and lower rolls are flat, the reduction is 30%, and the rolling speed is 60mm / s, ultimately obtaining a thick steel-aluminum corrugated rolled composite plate.

[0056] Example 2 This embodiment provides a thick steel-aluminum corrugated rolled composite plate, the preparation method of which includes: S1: AL6082 aluminum alloy sheet (length × width × thickness 200mm × 100mm × 2mm) is heated to 590℃ in a box-type resistance furnace and held for 1 hour. It is then quickly removed and stacked with a Q235B steel sheet (length × width × thickness 200mm × 100mm × 12mm) at room temperature, and fed into a two-roll mill. The upper roll of the two-roll mill is a corrugated roll (corresponding to the AL6082 aluminum sheet side), and the lower roll is a flat roll (corresponding to the Q235B steel sheet side). The reduction is 25%, and the rolling speed is 40mm / s, resulting in a Q235B / AL6082 intermediate plate with a corrugated interface. The corrugated structure has a wave height of 0.25mm and a wave pitch of 1mm~2mm.

[0057] S2: The AL6082 side of the Q235B / AL6082 intermediate plate is stacked with the AL5083 aluminum alloy plate (length × width × thickness 200mm × 100mm × 25mm) to form a billet, and the stack is secured tightly around the perimeter with steel wire. The billet is placed in a box-type resistance furnace, heated to 490℃ and held for 1 hour. After removal, it is quickly rolled on a two-roll mill with flat rolls on both the upper and lower rolls, a reduction of 35%, and a rolling speed of 40mm / s, ultimately obtaining a thick steel-aluminum corrugated rolled composite plate.

[0058] Example 3 This embodiment provides a thick steel-aluminum corrugated rolled composite plate, the preparation method of which includes: S1: AL6082 aluminum alloy sheet (length × width × thickness 200mm × 100mm × 4mm) is heated to 610℃ in a box-type resistance furnace and held at that temperature for 0.5h. It is then quickly removed and stacked with a Q235B steel sheet (length × width × thickness 200mm × 100mm × 20mm) at room temperature, and fed into a two-roll mill. The upper roll of the two-roll mill is a corrugated roll (corresponding to the AL6082 aluminum sheet side), and the lower roll is a flat roll (corresponding to the Q235B steel sheet side). The reduction is 30%, and the rolling speed is 50mm / s, resulting in a Q235B / AL6082 intermediate plate with a corrugated interface. The corrugated structure has a wave height of 0.3mm and a wave pitch of 1mm~2mm.

[0059] S2: The AL6082 side of the Q235B / AL6082 intermediate plate is stacked with the AL5083 aluminum alloy plate (length × width × thickness 200mm × 100mm × 29mm) to form a billet, and the stack is secured tightly around the perimeter with steel wire. The billet is placed in a box-type resistance furnace, heated to 510℃ and held for 0.5 hours. After removal, it is quickly rolled on a two-roll mill with flat rolls on both the upper and lower rolls, a reduction of 40%, and a rolling speed of 50mm / s, ultimately obtaining a thick steel-aluminum corrugated rolled composite plate.

[0060] Comparative Example 1 The difference between this comparative example and Example 1 is that the AL6082 aluminum alloy plate is replaced with an AL1060 pure aluminum plate of the same size.

[0061] Comparative Example 2 The difference between this comparative example and Example 1 is that the AL6082 aluminum alloy plate is replaced with an AL6061 aluminum alloy plate of the same size.

[0062] Comparative Example 3 The difference between this comparative example and Example 1 is that the AL6082 aluminum alloy plate is replaced with an AL6063 aluminum alloy plate of the same size.

[0063] Comparative Example 4 The difference between this comparative example and Example 1 is that in S1, corrugated rolling is replaced by flat roll rolling, and the rolling conditions are the same as in S2.

[0064] Comparative Example 5 The difference between this comparative example and Example 1 is that in S1, the thickness of the AL6082 aluminum alloy plate is 1 mm.

[0065] Comparative Example 6 The difference between this comparative example and Example 1 is that in S1, the thickness of the AL6082 aluminum alloy plate is 5mm.

[0066] Comparative Example 7 The difference between this comparative example and Example 1 is that in S1, the reduction of the corrugated rolling is 10%.

[0067] Comparative Example 8 The difference between this comparative example and Example 1 is that in S1, the reduction of the corrugated rolling is 40%.

[0068] Comparative Example 9 The difference between this comparative example and Example 1 is that in S1, the rolling speed of the corrugated rolling is 30 mm / s.

[0069] Comparative Example 10 The difference between this comparative example and Example 1 is that in S1, the rolling speed of the corrugated rolling is 70 mm / s.

[0070] Test case The composite plates prepared in Examples 1-3 and Comparative Examples 1-10 were subjected to simulated welding heat input tests. Specifically, pull-out samples were cut from the final composite plates and heated to 350℃ for 30 min followed by air cooling to room temperature, and then heated to 450℃ for 30 min followed by air cooling to room temperature before pull-out strength testing. The pull-out strength test was conducted in accordance with GB / T 228.1-2021. Each experiment was repeated three times, and the average value was taken. The results are shown in Table 1 and... Figure 2 As shown.

[0071] Table 1. Pull-out strength (MPa) of composite plates

[0072] As can be seen from Table 1, the pull-out strength of the composite plates prepared in Examples 1-3 increases significantly with the increase of the simulated heat input temperature, exhibiting positive temperature sensitivity, and E2 > 1.5E0.

[0073] The pull-out strength of the composite plate prepared in Comparative Example 1 decreased with increasing simulated heat input temperature; the pull-out strength of the composite plates prepared in Comparative Examples 2 and 3 also decreased with increasing simulated heat input temperature. Therefore, when using AL1060, AL6061, and AL6063 as interlayers, the bond strength of the steel-aluminum composite plate decreased after being subjected to heat at 350℃ and above; however, when using AL6082 as the interlayer, the pull-out strength not only did not decrease but increased with increasing temperature. After holding at 450℃ for 30 minutes, the strength increased by approximately 51.9% compared to before heat input, exhibiting a remarkably rare positive temperature sensitivity. This characteristic allows the Q235 / AL6082 / AL5083 composite plate, when used as a transition joint, to maintain or even enhance the interfacial bond at high welding temperatures, significantly improving the safety margin of the structural components.

[0074] In addition, in Comparative Example 4, there was no corrugated interface; in Comparative Examples 5 and 6, the AL6082 intermediate layer thickness was too thin or too thick; in Comparative Examples 7 and 8, the corrugated rolling reduction was too small or too large; and in Comparative Examples 9 and 10, the corrugated rolling speed was too slow or too fast. Although all of them used AL6082 as the intermediate layer and could still maintain a certain positive temperature sensitivity (E2 > E1 > E0), their pull-out strength after treatment at 450°C did not reach 1.5 times the strength before heat input (i.e., E2 < 1.5E0), and the strengthening range was significantly lower than that of Example 1 (E2 > 1.5E0). This indicates that only when the thickness of the intermediate layer of AL6082 (2mm~4mm), the corrugated structure (wave height 0.2mm~0.3mm, wave pitch 1mm~2mm), the corrugated rolling reduction (20%~30%), and the rolling speed (40mm / s~60mm / s) are all within the range of this application can significant positive temperature sensitivity and excellent resistance to thermal decay (E2>1.5E0) be obtained.

[0075] The present invention is not limited to the above embodiments. According to the concept of the present invention, by optimizing the thickness of the intermediate layer of AL6082, the rolling reduction, the corrugation parameters and the heat treatment process, the intensity window and the amplification level of positive temperature sensitivity can be further controlled.

[0076] In summary, the solution provided by this invention successfully yields a thick steel-aluminum corrugated rolled composite plate with excellent positive temperature sensitivity. Especially under welding heat conditions of 350℃~450℃, the bonding strength of the composite plate increases with increasing temperature, fundamentally overcoming the fatal defect of strength attenuation in traditional transition joints within this temperature range. This significantly improves the reliability and safety of the welded joint, meeting the requirements of transition joints for heavy-duty structures. Furthermore, the manufacturing process of this composite plate is simple and controllable, suitable for industrial production; it can be achieved using a common box-type resistance furnace and a two-roll mill, without the need for a vacuum or protective atmosphere, resulting in better cost and efficiency than explosive bonding.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A large thickness steel-aluminum corrugated roll-bonded clad plate having positive temperature sensitivity, characterized by, The thick steel-aluminum corrugated rolled composite plate includes a steel layer, an intermediate aluminum alloy layer and a surface aluminum alloy layer stacked in sequence. The steel layer is formed of Q235B steel plate, the intermediate aluminum alloy layer is formed of AL6082 aluminum alloy plate, and the surface aluminum alloy layer is formed of AL5083 aluminum alloy plate; the interface between the steel layer and the intermediate aluminum alloy layer has a corrugated structure. The pull-out strength of the thick steel-aluminum corrugated rolled composite plate after simulated welding heat input treatment time t at temperature T1 is E1; the pull-out strength of the thick steel-aluminum corrugated rolled composite plate after simulated welding heat input treatment time t at temperature T2 is E2; and the pull-out strength of the thick steel-aluminum corrugated rolled composite plate before simulated welding heat input treatment is E0; T2 > T1, E2 > E1 > E0.

2. The thick steel-aluminum corrugated rolled composite plate according to claim 1, characterized in that, The thickness of the thick steel-aluminum corrugated rolled composite plate is 23mm~26mm; And / or, the thickness of the Q235B steel plate is 12mm~20mm; And / or, the thickness of the AL6082 aluminum alloy plate is 2mm~4mm; And / or, the thickness of the surface aluminum alloy layer is 20mm~29mm.

3. The thick steel-aluminum corrugated rolled composite plate according to claim 1, characterized in that, The wave height in the corrugated structure is 0.2mm~0.3mm, and the wave pitch is 1mm~2mm.

4. The large-gauge steel-aluminum corrugated roll-bonded panel according to claim 1, characterized by, 450℃≥T2>T1≥350℃; And / or, t is 25min~35min.

5. The large-gauge steel-aluminum corrugated roll composite sheet according to claim 1, characterized by E2≥1.5E0.

6. A method for preparing a thick steel-aluminum corrugated rolled composite plate as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1: After stacking Q235B steel plate and heated AL6082 aluminum alloy plate, corrugated rolling is performed to obtain a Q235B / AL6082 intermediate plate with a corrugated interface. S2: The Q235B / AL6082 intermediate plate and AL5083 aluminum alloy plate are stacked together, heated and then rolled by flat rolls to obtain a thick steel-aluminum corrugated rolled composite plate.

7. The production method according to claim 6, wherein The S1 process includes at least one of the following characteristics: Feature 1: The AL6082 aluminum alloy plate is heated at 590℃~610℃ for 0.5h~1h, and then corrugated rolled with Q235B steel plate at room temperature; Feature 2: The two-roll mill used for corrugated rolling includes corrugated rolls and flat rolls, which correspond to AL6082 aluminum alloy plate and Q235B steel plate, respectively; Feature 3: The reduction of corrugated rolling is 20%~30%, and the rolling speed is 40mm / s~60mm / s.

8. The preparation method according to claim 6, characterized in that, The S2 process includes at least one of the following characteristics: Feature 4: The AL5083 aluminum alloy plate layer is in contact with the AL6082 side of the Q235B / AL6082 intermediate plate; Feature 5: The Q235B / AL6082 intermediate plate and AL5083 aluminum alloy plate are stacked and then rolled by flat rolls after being heated at 490℃~510℃ for 0.5h~1h. Feature 6: The reduction of the flat roll is 30%~40%, and the rolling speed is 40mm / s~60mm / s.

9. The application of a thick steel-aluminum corrugated rolled composite plate as described in any one of claims 1 to 5 in a steel-aluminum transition joint.

10. An apparatus, comprising: Including the thick steel-aluminum corrugated rolled composite plate as described in any one of claims 1 to 5.

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