Aluminum alloy bar, hot rolling method of aluminum alloy bar

Abstract

The present invention provides an aluminum alloy bar and a hot rolling method for the aluminum alloy bar. The hot rolling method comprises: performing a three-dimensional scanning on the hot rolling mill to obtain the nominal diameter D of each roller. n , Wire inscribed circle diameter d n , get the reduction ratio k n , calculate the hole cross-sectional area S n ; According to the flow ratio F n Calculate the flow rate L n ; Calculate the roller speed r n , simulated motor speed ω n ; The aluminum alloy ingot is cast at the speed ω n Hot rolling is performed through 1 to n passes to produce aluminum alloy bars; the flow ratio for soft aluminum alloys is 0.95 to 1.10, and for hard aluminum alloys, the flow ratio is 0.90 to 1.05. This invention establishes a correlation between the roll parameters for each pass in an aluminum alloy hot rolling mill, combining the inherent properties of soft and hard aluminum alloys to rapidly calculate the motor speed for each roll suitable for the material being rolled. This can be directly applied to actual hot rolling, improving material forming quality and production efficiency while reducing the cost of parameter exploration.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and in particular to an aluminum alloy bar and a hot rolling method for the aluminum alloy bar. Background Art

[0002] Traditional aluminum alloy production methods typically use extrusion to produce aluminum alloy bars. However, due to equipment limitations, production efficiency is low, and a single bar weighs approximately 20-50 kg, which cannot meet the needs of continuous production. Using an aluminum alloy bar hot rolling mill for direct hot rolling of large ingots can produce single, jointless bars or coils weighing over 200 kg. This offers high production efficiency and rapid forming speeds, and has become the mainstream production method for high-end wire rods. An aluminum alloy bar hot rolling mill consists of eight flat vertical rolls and 14 Y-shaped rolls. In actual rolling production, the rolling speed matching of each roll is determined empirically. However, for different grades of aluminum alloys, due to differences in structure and performance, multiple experiments are required to match the rolling speed of each roller. The experimental efficiency is low, human resources, raw materials and energy are seriously wasted, and the parameter exploration efficiency is low. On the other hand, even if the bar can be rolled and flowed smoothly, it is easy to cause changes in the macro or micro structural uniformity due to unreasonable speed matching between some rollers, which gradually accumulates and causes surface folding, mid-line breakage, and rolling cracking, affecting production efficiency and quality.

[0003] Hot rolling is the mainstream production method for aluminum alloy bars, but different grades of aluminum alloy have varying properties. Soft alloys, such as the 1xxx series, are soft and have high elongation, while hard alloys, such as the 2xxx, 5xxx, and 7xxx series, are heat-hardened or work-hardened, resulting in high strength, low elongation, and poor forming performance. When rolling soft alloys, material can easily overflow the roll gap, leading to surface quality issues such as folding and stacking. When hot-rolling hard alloys, due to the gradual decrease in elongation, wire breakage or end cracking can occur, making continuous production difficult. Summary of the Invention

[0004] The main purpose of the present invention is to provide an aluminum alloy bar and a hot rolling method for aluminum alloy bars, so as to solve the problem that the hot rolling method for aluminum alloy bars in the existing technology is difficult to take into account the forming quality of soft aluminum alloy and hard aluminum alloy and requires a lot of preliminary parameter exploration.

[0005] To achieve the above object, according to one aspect of the present invention, a hot rolling method for aluminum alloy bars is provided. The hot rolling method is performed in a hot rolling mill and comprises the following steps: step S1, preparing an aluminum alloy ingot and a master alloy into an aluminum alloy ingot according to the composition ratio of the aluminum alloy bar; step S2, determining the simulated motor speed ω of the roller in the nth pass during the hot rolling process n Step S21, perform a three-dimensional scan on the hot rolling mill to obtain the nominal diameter D of each rolln , the diameter of the inscribed circle of each roller wire d n , and obtain the reduction ratio k of each roller at the same time n , calculate the hot rolling mill pass cross-sectional area S n ; Step S22, according to the flow ratio F of the hot rolling mill n , calculate the flow rate L of the hot rolling mill n Step S23, calculate the roll speed r of the hot rolling mill n , simulated motor speed ω n ; Step S3, the aluminum alloy ingot is fed into the hot rolling mill to simulate the motor speed ω n As the actual motor speed, 1 to n passes of hot rolling are performed to obtain an aluminum alloy bar; when the aluminum alloy bar is a soft aluminum alloy, the flow ratio is 0.95 to 1.10; when the aluminum alloy bar is a hard aluminum alloy, the flow ratio is 0.90 to 1.05.

[0006] Furthermore, in step S2, the hole cross-sectional area S n Calculated by formula (1):

[0007] S n =π×d n 2 ÷4(1).

[0008] Furthermore, in step S2, the flow rate L n Calculated by formula (2):

[0009] L n =L n-1 ×F n (2); where L n-1 The flow rate of the previous pass, L1 is 430000~440000mm 2 / s.

[0010] Furthermore, in step S2, the roller speed r n Calculated by formula (3):

[0011] r n =L n ÷S n ÷(D n ÷2)(3).

[0012] Furthermore, in step S2, the motor speed ω is simulated. n Calculated by formula (4):

[0013] ω n =r n ×k n ×30÷π(4).

[0014] Further, the hard aluminum alloy includes one or more of a 5xxx series aluminum alloy, a 2xxx series aluminum alloy, a 6xxx series aluminum alloy, and a 7xxx series aluminum alloy; and / or the soft aluminum alloy includes a 1xxx series aluminum alloy.

[0015] Furthermore, in step S22, the flow ratio F of the hot rolling mill is determined according to the alloy series of the aluminum alloy bar. n ; When the alloy series of the aluminum alloy bar is 1xxx series aluminum alloy, F n is 1.05~1.10; when the alloy series of the aluminum alloy bar is 2xxx series aluminum alloy, 6xxx series aluminum alloy or 7xxx series aluminum alloy, F n is 0.95~1.05; when the alloy series of the aluminum alloy bar is 5xxx series aluminum alloy, F n It is 0.90~0.95.

[0016] Furthermore, after step S23, step S2 further includes the following steps: digitally modeling the hot rolling mill to obtain a digital model of the hot rolling mill; simulating the motor speed ω n Run the digital model of the hot rolling mill to obtain the aluminum alloy simulated bar, and visually observe the forming state of the aluminum alloy simulated bar under the current conditions: when the aluminum alloy simulated bar has no forming defects, the simulated motor speed ω n Hot rolling is performed as the actual motor speed; when forming defects appear in the aluminum alloy simulated bar, steps S22 and S23 are repeated to adjust the flow ratio until the aluminum alloy simulated bar no longer has forming defects. The motor speed at this time is the second simulated motor speed, and hot rolling is performed using the second simulated motor speed as the actual motor speed; forming defects include stacking, tensile fracture and opening cracking.

[0017] Furthermore, when the aluminum alloy simulated bars are stacked, the flow ratio is adjusted to 1.05~1.10; when the aluminum alloy simulated bars are tensile fractured or cracked, the flow ratio is adjusted to 0.90~0.95.

[0018] Furthermore, in step S1, the aluminum ingot and the intermediate alloy are mixed according to the composition ratio of the aluminum alloy rod, and semi-continuous casting is performed to obtain an aluminum alloy cast rod; the aluminum alloy cast rod is sequentially subjected to homogenization heat treatment and milling to obtain an aluminum alloy cast ingot.

[0019] According to another aspect of the present invention, there is provided an aluminum alloy bar obtained by the hot rolling method of the present invention.

[0020] Furthermore, the grain boundary width of the aluminum alloy rod is 15~30μm, the total area percentage of Brass texture, Copper texture and S texture is 10~30%, the area percentage of Cube texture is 50~70%, and the grain core-surface difference is ≤1.0 level; and / or the elongation of the aluminum alloy rod is 10~30%, and the range of tensile strength of the whole coil of 200~3000kg is 2~15MPa.

[0021] By applying the technical solution of the present invention, by establishing a correlation between the parameters of the rolls in each pass in an aluminum alloy hot rolling mill, combining the inherent properties of soft aluminum alloys and hard aluminum alloys, confirming the flow ratio of the front and rear rolling passes of the rolls, and quickly obtaining the motor speed of each roll suitable for the current rolling material through calculation, the technology can be directly applied to the actual hot rolling process, significantly improving the material forming quality and production efficiency, and reducing the cost of experimental exploration of parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 A hot rolling process flow chart according to an embodiment of the present invention is shown;

[0024] Figure 2 It shows a hot rolling process flow chart according to Example 1 of the present invention;

[0025] Figure 3 The digital model of the hot rolling equipment according to the embodiment 1 of the present invention is shown;

[0026] Figure 4 shows the grain morphology according to Example 1 of the present invention;

[0027] Figure 5 shows the grain morphology according to Comparative Example 1;

[0028] Figure 6 shows the defect morphology according to Comparative Example 1;

[0029] Figure 7 The stacking defects generated by hot rolling in the digital model according to Comparative Example 2 are shown;

[0030] Figure 8 The stacking defects generated by hot rolling in actual production according to Comparative Example 2 are shown. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] As described in the background of the present invention, the existing hot rolling method for aluminum alloy bars has the problem that it is difficult to balance the forming quality of soft aluminum alloys and hard aluminum alloys, and a large amount of preliminary parameter exploration is required. In order to solve the above problems, in a typical embodiment of the present invention, a hot rolling method for aluminum alloy bars is provided. The hot rolling method is carried out in a hot rolling mill and includes the following steps: step S1, preparing aluminum alloy ingots and intermediate alloys into aluminum alloy ingots according to the composition ratio of the aluminum alloy bars; step S2, determining the simulated motor speed ω of the nth pass roller during the hot rolling process n Step S21, perform a three-dimensional scan on the hot rolling mill to obtain the nominal diameter D of each roll n , the diameter of the inscribed circle of each roller wire d n , and obtain the reduction ratio k of each roller at the same time n , calculate the hot rolling mill pass cross-sectional area S n ; Step S22, according to the flow ratio F of the hot rolling mill n , calculate the flow rate L of the hot rolling mill n Step S23, calculate the roll speed r of the hot rolling mill n , simulated motor speed ω n ; Step S3, the aluminum alloy ingot is fed into the hot rolling mill to simulate the motor speed ω n As the actual motor speed, 1 to n passes of hot rolling are performed to obtain an aluminum alloy bar; when the aluminum alloy bar is a soft aluminum alloy, the flow ratio is 0.95 to 1.10; when the aluminum alloy bar is a hard aluminum alloy, the flow ratio is 0.90 to 1.05.

[0033] Among them, soft aluminum alloy refers to the hardness HB≤50N / mm after hot rolling 2 Aluminum alloy, hard aluminum alloy refers to the hardness HB> 50N / mm after hot rolling 2 of aluminum alloy.

[0034] The present invention designs a calculation process based on material properties and hot rolling mill parameters. n d n 、k n , calculate S n , determine F n , calculate L n 、r n 、ω n, to obtain the optimal motor speed setting for each hot rolling pass roller. The present invention establishes the correlation between the speed of each roller, the speed of the roller motor, the hole interface, and the bar flow in the aluminum alloy hot rolling mill, combines the inherent properties of soft aluminum alloys and hard aluminum alloys, confirms the flow ratio of the front and rear rolling passes of the rollers, and quickly obtains the motor speed of each roller suitable for the current rolling material through calculation, significantly improving the material forming quality and production efficiency, and reducing the cost of experimental exploration parameters. At the same time, by reasonably controlling parameters such as the bar rolling flow rate, it is possible to avoid energy accumulation and coarse grain defects caused by long-term friction between the material and the roller, which is conducive to obtaining aluminum alloy rolled bars with fine grain size and appropriate grain boundary width, without coarse grain ring defects; it can also obtain a reasonable deformation orientation texture and recrystallization texture matching, significantly improving the material uniformity and ductility. Among them, the reduction ratio k of each roller n It can be obtained from the nameplate of the motor used. The hot rolling process flow chart of an embodiment of the present invention is as follows Figure 1 shown.

[0035] Typically but not limitatively, when the aluminum alloy rod is a soft aluminum alloy, the flow ratio is 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10 or a range consisting of any two of them.

[0036] Typically but not limitatively, when the aluminum alloy rod is a hard aluminum alloy, the flow ratio is 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05 or a range consisting of any two of them.

[0037] In a preferred embodiment, in step S2, the hole cross-sectional area S n Calculated by formula (1):

[0038] S n =π×d n 2 ÷4(1).

[0039] In formula (1), in actual production, even if the rollers are designed to be circular, the aluminum alloy to be rolled will not fully fill the roller gap. When the actual aluminum alloy ingot / bar / wire passes through the rollers, it will not have a completely circular cross-section. At this time, the diameter d of the inscribed circle of the aluminum alloy bar passing through the rollers is collected. n , the hole area calculated by the formula is relatively more accurate.

[0040] In a preferred embodiment, in step S2, the flow rate L nCalculated by formula (2):

[0041] L n =L n-1 ×F n (2); where L n-1 The flow rate of the previous pass, L1 is 430000~440000mm 2 / s.

[0042] In formula (2), the flow rate of each pass L n From the previous L n-1 Multiply by the flow ratio F set according to the type of aluminum alloy to be prepared n The flow rate L1 of the first pass is obtained by comprehensive equipment rolling capacity and actual ingot size factors.

[0043] In a preferred embodiment, in step S2, the roller speed r n Calculated by formula (3):

[0044] r n =L n ÷S n ÷(D n ÷2)(3).

[0045] In formula (3), L n ÷S n Get the actual flow velocity of the bar, flow velocity ÷ (D n ÷2) to get the roller speed r n .

[0046] In a preferred embodiment, in step S2, the motor speed ω is simulated. n Calculated by formula (4):

[0047] ω n =r n ×k n ×30÷π(4).

[0048] In formula (4), the roller speed r n The unit is rad / s, which is the angular velocity of the roller per second. Since 2π×arc velocity = angular velocity, the unit of motor speed is r / min, which is 2π×ω n =r n ×k n ×60, convert it and you will get it.

[0049] As described above, the hot rolling method of the present invention can achieve the desired forming quality for both soft and hard aluminum alloy bars, making it applicable to aluminum alloys of varying hardness. In a preferred embodiment, the hard aluminum alloy includes one or more of a 5xxx series aluminum alloy, a 2xxx series aluminum alloy, a 6xxx series aluminum alloy, and a 7xxx series aluminum alloy; and / or the soft aluminum alloy includes a 1xxx series aluminum alloy.

[0050] In a preferred embodiment, the matching relationship between each pass and the motor in the hot rolling mill is as follows: 1 motor drives 1 pass, or 1 motor drives 2 passes, or 1 motor drives a passes, a is 3 to 7. When using 1 motor to drive 2 passes or a passes, the reduction ratio k of each roller is used. n Controlling the motor speed matches the speed of each roller. These conditions facilitate the adaptability of the hot rolling method of the present invention to a variety of equipment. Some equipment can utilize a single motor to drive multiple rollers to reduce costs or facilitate maintenance. The motor refers to the electrical equipment that drives the rollers.

[0051] In a preferred embodiment, in step S22, the flow ratio F of the hot rolling mill is determined according to the alloy series of the aluminum alloy bar. n ; When the alloy series of the aluminum alloy bar is 1xxx series aluminum alloy, F n is 1.05~1.10; when the alloy series of the aluminum alloy bar is 2xxx series aluminum alloy, 6xxx series aluminum alloy or 7xxx series aluminum alloy, F n is 0.95~1.05; when the alloy series of the aluminum alloy bar is 5xxx series aluminum alloy, F n It is 0.90~0.95.

[0052] For 1xxx series aluminum alloys, since this type of aluminum alloy cannot be processed and strengthened, it cannot be heat-treated and strengthened, and belongs to the category of soft alloys. Stacking and overflow roll gap are easy to occur during the rolling process, so F is preferred. n The value is 1.05~1.10 to give the bar a slightly larger tensile stress to avoid stacking and allow the bar to be rolled smoothly in the roller table.

[0053] For 2xxx series aluminum alloy, 6xxx series aluminum alloy or 7xxx series aluminum alloy, the above types of aluminum alloy are medium-high composition alloys, can be heat-treated and strengthened, and belong to the category of hard alloys, so F is preferred. n The value is 0.95~1.05 to give the bar moderate tensile stress to avoid defects such as stacking, tensile fracture and opening cracking.

[0054] For 5xxx series aluminum alloy, this type of aluminum alloy is a medium-composition alloy that can be processed and hardened. As the processing volume increases, the hardening degree increases significantly, and it is easy to produce head end cracking defects. Therefore, F is preferred. nIt is 0.90~0.95 to give the bar a slight compressive stress, so that rolling and defect healing can be carried out simultaneously.

[0055] Typically, but not limiting, when the alloy series of the aluminum alloy bar is 1xxx series aluminum alloy, F n It is 1.05, 1.06, 1.07, 1.08, 1.09, 1.10 or a range consisting of any two of them.

[0056] Typically, but not limited to, when the alloy series of the aluminum alloy bar is 2xxx series aluminum alloy, 6xxx series aluminum alloy or 7xxx series aluminum alloy, F n It is 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05 or a range consisting of any two of them.

[0057] Typically, but not limited to, when the alloy series of the aluminum alloy bar is 5xxx series aluminum alloy, F n It is 0.90, 0.91, 0.92, 0.93, 0.94, 0.95 or a range consisting of any two of them.

[0058] In a preferred embodiment, after step S23, step S2 further includes the following steps: digitally modeling the hot rolling mill to obtain a digital model of the hot rolling mill; simulating the motor speed ω n Run the digital model of the hot rolling mill to obtain the aluminum alloy simulated bar, and visually observe the forming state of the aluminum alloy simulated bar under the current conditions: when the aluminum alloy simulated bar has no forming defects, the simulated motor speed ω n Hot rolling is performed using the actual motor speed. When forming defects occur in the simulated aluminum alloy bar, steps S22 and S23 are repeated, and the flow ratio is adjusted until the simulated aluminum alloy bar no longer exhibits forming defects. The motor speed at this point is the second simulated motor speed, and hot rolling is performed using the second simulated motor speed as the actual motor speed. Forming defects include stacking, tensile fracture, and opening cracking. Stacking, tensile fracture, and opening cracking are conventional defect morphologies that are understood by those skilled in the art.

[0059] The present invention addresses the production problems of stacking, tensile fracture, and opening cracking that are very likely to occur during the hot rolling process of aluminum alloy bars. It uses digital modeling to simulate the hot rolling forming state of the material under the current flow ratio setting. When the above defects occur in the alloy bar, the flow ratio is continuously adjusted and controlled to an appropriate range to achieve smooth forming of the material during the hot rolling process. First, the appropriate parameters are obtained through digital simulation screening and then actual production verification is carried out, which can greatly reduce experimental costs and reduce the cracking ratio in the material production process. The present invention establishes the flow relationship of the aluminum alloy bar between each roller, integrates the material properties, uses digital simulation to calculate the optimal flow ratio, designs and matches the speed of each roller, and then sets the motor speed in the system, so as to better ensure the smooth rolling and forming of the alloy bar and improve production quality and efficiency.

[0060] The process of digital modeling of the hot rolling mill can be carried out using conventional modeling software in the field. For example, first use Auto CAD to draw the three-dimensional scanned rollers, then import the model into Deform, and enter the relevant rolling parameters to carry out digital simulation to obtain the digital model of the hot rolling mill. The relevant rolling parameters include the starting rolling temperature, rolling speed and final rolling temperature. The rolling speed is the simulated motor speed ω n The starting rolling temperature and the finishing rolling temperature can be set according to the type of aluminum alloy bar, for example, the starting rolling temperature is 400~500℃, and the finishing rolling temperature is 150~250℃.

[0061] When material piles up, the flow rate ratio is increased to impart slightly greater tensile stress to the bars, allowing for smooth rolling on the rollers. When tensile fractures or cracking occur, indicating excessive rear-end rolling speed, the flow rate ratio is reduced to impart slight compressive stress, allowing for simultaneous rolling and defect healing. Based on this, in a preferred embodiment, when simulated aluminum alloy bars pile up, the flow rate ratio is adjusted to 1.05-1.10; when tensile fractures or cracking occur, the flow rate ratio is adjusted to 0.90-0.95.

[0062] In a preferred embodiment, in step S1, an aluminum ingot and a master alloy are mixed according to the composition ratio of the aluminum alloy rod and semi-continuously cast to obtain an aluminum alloy cast rod; the aluminum alloy cast rod is then subjected to homogenization heat treatment and milling to obtain an aluminum alloy ingot; the diameter φ of the aluminum alloy ingot is 125-145 mm. The semi-continuous casting, homogenization heat treatment, and milling processes can use conventional parameters in the art, such as melting the aluminum ingot and the master alloy at 660-750°C to obtain the aluminum alloy cast rod; the aluminum alloy cast rod is held at 450-550°C for 24-48 hours, subjected to homogenization heat treatment, and then milled to remove the surface oxide layer to obtain a milled aluminum alloy ingot.

[0063] In another typical embodiment of the present invention, an aluminum alloy bar is also provided, which is obtained using the above-mentioned hot rolling method of the present invention, so that the hot rolling process of the aluminum alloy bar can take into account the forming quality of soft aluminum alloy and hard aluminum alloy, and does not require a large amount of preliminary parameter exploration.

[0064] The aluminum alloy bar of the present invention reasonably controls the rolling flow of the bar during the hot rolling process to avoid energy accumulation and coarse grain defects caused by long-term or friction between the material and the roller. The obtained aluminum alloy rolled bar has a moderate grain boundary width, a small grain core-surface difference, a small grain size, and no coarse grain ring defects. It can obtain a reasonable deformation orientation texture that matches the recrystallization texture, and controls the elongation to be moderate. The extreme difference in tensile strength of the whole coil is small, which significantly improves the material uniformity and has excellent forming quality. In a preferred embodiment, the grain boundary width of the aluminum alloy bar is 15~30μm, the total area percentage of Brass texture, Copper texture and S texture is 10~30%, the area percentage of Cube texture is 50~70%, the grain core-surface difference is ≤1.0 level; and / or the elongation of the aluminum alloy bar is 10~30%, and the extreme difference in tensile strength of the whole coil of 200~3000kg is 2~15MPa.

[0065] The 200-3000 kg coil tensile strength extreme difference indicates that, when the hot rolling method of the present invention is used in a hot rolling mill, a single aluminum alloy bar weighing 200-3000 kg can be produced, and the difference between the maximum and minimum coil tensile strengths is 3-15 MPa. This parameter can indicate the material uniformity and processing stability of the hot rolling method; a smaller difference indicates better material uniformity and processing stability.

[0066] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0067] Example 1

[0068] To prepare 1060 aluminum alloy bar, which is a soft aluminum alloy, the hot rolling method is as follows. The hot rolling process flow chart is shown in Figure 2 :

[0069] Step S1: mixing an aluminum ingot and a master alloy according to the composition ratio of the aluminum alloy rod, and performing semi-continuous casting to obtain an aluminum alloy cast rod; and sequentially performing homogenization heat treatment and surface milling on the aluminum alloy cast rod to obtain an aluminum alloy ingot; the diameter of the aluminum alloy ingot is φ145 mm;

[0070] Step S2, determining the simulated motor speed ω of the n-th roller in the hot rolling process n ;

[0071] Step S21, use RigelScan Max intelligent handheld laser 3D scanner to perform 3D scanning on the hot rolling mill to obtain the nominal diameter D of each roll. n , the diameter of the inscribed circle of each roller wire d n At the same time, the reduction ratio k of each roller is obtained from the motor nameplate n , according to formula S n =π×d n 2 ÷4, calculate the hole cross-sectional area S of the hot rolling mill n ;

[0072] Step S22: According to the properties of 1060 aluminum alloy bar, the initial flow ratio of the hot rolling mill is determined to be 1.05-1.10 (the optimal F ratio under the experimental conditions is verified by digital modeling). n =1.05), according to the formula L n =L n-1 ×F n , calculate the flow rate L of the hot rolling mill n ;

[0073] Step S23, according to formula r n =L n ÷S n ÷(D n ÷2), ω n =r n ×k n ×30÷π, and further calculate the roll speed r of the hot rolling mill n , simulated motor speed ω n ;

[0074] To digitally model the hot rolling mill, first use Auto CAD to draw the 3D scanned rolls, then import the Deform model, and input the relevant rolling parameters (rolling speed, i.e., the simulated motor speed, ω n , the starting rolling temperature is 440℃, and the finishing rolling temperature is 200℃), digital simulation can be carried out to obtain the digital model of the hot rolling mill, such as Figure 3 As shown, the rolled bar moves along the preset rolling direction in the roller table formed by the rollers, thereby being rolled; the motor speed ω is simulated n Run the digital model of the hot rolling mill to obtain the forming state of the aluminum alloy simulated bar under the current conditions, and observe visually. When the digital model of the hot rolling mill is completed, check: when there is no forming defect in the aluminum alloy simulated bar, the simulated motor speed ω nHot rolling is performed as the actual motor speed; when the aluminum alloy simulated bar has forming defects, steps S22 and S23 are repeated to adjust the flow ratio: when the aluminum alloy simulated bar is stacked, the flow ratio is adjusted to 1.05~1.10; when the aluminum alloy simulated bar has tensile fracture or opening cracking, the flow ratio is adjusted to 0.90~0.95; until the aluminum alloy simulated bar no longer has forming defects, the parameters of the hot rolling process are shown in Table 1, and the optimal simulated motor speed for each pass is calculated.

[0075] Step S3, feeding the aluminum alloy ingot into the hot rolling mill, and simulating the motor speed ω at each pass. n As the actual motor speed, n passes of hot rolling are performed to obtain aluminum alloy bars.

[0076]

[0077] Among them, each pass from 1 to 8 is driven by one motor; passes from 9 to 14 are driven by one motor, and different reduction ratios are used to control the motor speed and match the speed of each roller; passes from 15 to 22 are driven by one motor for two passes.

[0078] Example 2

[0079] The difference from Example 1 is that no digital modeling is performed, and the motor speed ω is directly simulated by the calculated passes. n As the actual motor speed of each pass, n passes of hot rolling are performed to obtain an aluminum alloy bar.

[0080] Example 3

[0081] The difference from Example 2 is that, in order to prepare 1060 aluminum alloy bars, the flow rate of the hot rolling mill in step S22 is F n =1.08.

[0082] Example 4

[0083] The difference from Example 2 is that, in order to prepare 1060 aluminum alloy bars, the flow rate of the hot rolling mill in step S22 is F n =1.10.

[0084] Example 5

[0085] To prepare 2024 aluminum alloy bar, which is a hard aluminum alloy, the hot rolling method is as follows:

[0086] Step S1: mixing an aluminum ingot and a master alloy according to the composition ratio of the aluminum alloy rod, and performing semi-continuous casting to obtain an aluminum alloy cast rod; and sequentially performing homogenization heat treatment and surface milling on the aluminum alloy cast rod to obtain an aluminum alloy ingot; the diameter of the aluminum alloy ingot is φ145 mm;

[0087] Step S2, determining the simulated motor speed ω of the n-th roller in the hot rolling process n ;

[0088] Step S21, use RigelScan Max intelligent handheld laser 3D scanner to perform 3D scanning on the hot rolling mill to obtain the nominal diameter D of each roll. n , the diameter of the inscribed circle of each roller wire d n At the same time, the reduction ratio k of each roller is obtained from the motor nameplate n , according to formula S n =π×d n 2 ÷4, calculate the hole cross-sectional area S of the hot rolling mill n ;

[0089] Step S22: According to the properties of the 2024 aluminum alloy bar, the initial flow ratio of the hot rolling mill is determined to be 0.95-1.05 (the optimal F ratio under the experimental conditions is verified by digital modeling). n =1.0), according to the formula L n =L n-1 ×F n , calculate the flow rate L of the hot rolling mill n ;

[0090] Step S23, according to formula r n =L n ÷S n ÷(D n ÷2)、ω n =r n ×k n ×30÷π, and further calculate the roll speed r of the hot rolling mill n , simulated motor speed ω n ;

[0091] To digitally model the hot rolling mill, first use Auto CAD to draw the 3D scanned rolls, then import the Deform model, and input the relevant rolling parameters (rolling speed, i.e., the simulated motor speed, ω n , the starting rolling temperature is 440℃, the finishing rolling temperature is 200℃), digital simulation can be carried out to obtain the digital model of the hot rolling mill; the motor speed ω n Run the digital model of the hot rolling mill to obtain the forming state of the aluminum alloy simulated bar under the current conditions, and observe visually. When the digital model of the hot rolling mill is completed, check: when there is no forming defect in the aluminum alloy simulated bar, the simulated motor speed ω nHot rolling is performed as the actual motor speed; when the aluminum alloy simulated bar has forming defects, repeat steps S22 and S23 and adjust the flow ratio: when the aluminum alloy simulated bar is stacked, adjust the flow ratio to 1.05~1.10; when the aluminum alloy simulated bar has tensile fracture or opening cracking, adjust the flow ratio to 0.90~0.95; until the aluminum alloy simulated bar no longer has forming defects, the parameters of the hot rolling process are shown in Table 2, and the optimal simulated motor speed for each pass is calculated.

[0092] Step S3, feeding the aluminum alloy ingot into the hot rolling mill, and simulating the motor speed ω at each pass. n As the actual motor speed, n passes of hot rolling are performed to obtain aluminum alloy bars.

[0093]

[0094] Among them, each pass from 1 to 8 is driven by one motor; passes from 9 to 14 are driven by one motor, and different reduction ratios are used to control the motor speed and match the speed of each roller; passes from 15 to 22 are driven by one motor for two passes.

[0095] Example 6

[0096] The difference from Example 5 is that no digital modeling is performed, and the motor speed ω is directly simulated using the calculated passes. n As the actual motor speed of each pass, n passes of hot rolling are performed to obtain an aluminum alloy bar.

[0097] Example 7

[0098] The difference from Example 6 is that, in order to prepare 6061 aluminum alloy bars, the flow rate of the hot rolling mill in step S22 is F n =0.95.

[0099] Example 8

[0100] The difference from Example 6 is that, in order to prepare 7075 aluminum alloy bars, the flow rate of the hot rolling mill in step S22 is F n =1.05.

[0101] Example 9

[0102] To prepare 5056 aluminum alloy bar, which is a hard aluminum alloy, the hot rolling method is as follows:

[0103] Step S1: mixing an aluminum ingot and a master alloy according to the composition ratio of the aluminum alloy rod, and performing semi-continuous casting to obtain an aluminum alloy cast rod; and sequentially performing homogenization heat treatment and surface milling on the aluminum alloy cast rod to obtain an aluminum alloy ingot; the diameter of the aluminum alloy ingot is φ145 mm;

[0104] Step S2, determining the simulated motor speed ω of the n-th roller in the hot rolling process n ;

[0105] Step S21, use RigelScan Max intelligent handheld laser 3D scanner to perform 3D scanning on the hot rolling mill to obtain the nominal diameter D of each roll. n , the diameter of the inscribed circle of each roller wire d n At the same time, the reduction ratio k of each roller is obtained from the motor nameplate n , according to formula S n =π×d n 2 ÷4, calculate the hole cross-sectional area S of the hot rolling mill n ;

[0106] Step S22: According to the properties of the 5056 aluminum alloy bar, the initial flow ratio of the hot rolling mill is determined to be 0.90-0.95 (the optimal F ratio under the experimental conditions is verified by digital modeling). n =0.9), according to the formula L n =L n-1 ×F n , calculate the flow rate L of the hot rolling mill n ;

[0107] Step S23, according to formula r n =L n ÷S n ÷(D n ÷2)、ω n =r n ×k n ×30÷π, and further calculate the roll speed r of the hot rolling mill n , simulated motor speed ω n ;

[0108] To digitally model the hot rolling mill, first use Auto CAD to draw the 3D scanned rolls, then import the Deform model, and input the relevant rolling parameters (rolling speed, i.e., the simulated motor speed, ω n , the starting rolling temperature is 440℃, the finishing rolling temperature is 200℃), digital simulation can be carried out to obtain the digital model of the hot rolling mill; the motor speed ω n Run the digital model of the hot rolling mill to obtain the forming state of the aluminum alloy simulated bar under the current conditions, and observe visually. When the digital model of the hot rolling mill is completed, check: when there is no forming defect in the aluminum alloy simulated bar, the simulated motor speed ω nHot rolling is performed as the actual motor speed; when the aluminum alloy simulated bar has forming defects, steps S22 and S23 are repeated to adjust the flow ratio: when the aluminum alloy simulated bar is stacked, the flow ratio is adjusted to 1.05~1.10; when the aluminum alloy simulated bar has tensile fracture or opening cracking, the flow ratio is adjusted to 0.90~0.95; until the aluminum alloy simulated bar no longer has forming defects, the parameters of the hot rolling process are shown in Table 3, and the optimal simulated motor speed for each pass is calculated.

[0109] Step S3, feeding the aluminum alloy ingot into the hot rolling mill, and performing the simulation of the motor speed ω at each pass. n As the actual motor speed, n passes of hot rolling are performed to obtain aluminum alloy bars.

[0110]

[0111] Among them, each pass from 1 to 8 is driven by one motor; passes from 9 to 14 are driven by one motor, and different reduction ratios are used to control the motor speed and match the speed of each roller; passes from 15 to 22 are driven by one motor for two passes.

[0112] Example 10

[0113] The difference from Example 9 is that no digital modeling is performed, and the motor speed ω is directly simulated using the calculated passes. n As the actual motor speed of each pass, n passes of hot rolling are performed to obtain an aluminum alloy bar.

[0114] Example 11

[0115] The difference from Example 10 is that, in order to prepare 5056 aluminum alloy bars, the flow rate of the hot rolling mill in step S22 is F n =0.93.

[0116] Example 12

[0117] The difference from Example 10 is that, in order to prepare 5056 aluminum alloy bars, the flow rate of the hot rolling mill in step S22 is F n =0.95.

[0118] Comparative Example 1

[0119] The difference from Example 1 is that, in order to prepare 1060 aluminum alloy bars, the flow ratio F of the hot rolling mill is fixed. n =1.2. The parameters of hot rolling process under this condition are shown in Table 4.

[0120]

[0121] Among them, each pass from 1 to 8 is driven by one motor; passes from 9 to 14 are driven by one motor, and different reduction ratios are used to control the motor speed and match the speed of each roller; passes from 15 to 22 are driven by one motor for two passes.

[0122] Comparative Example 2

[0123] The difference from Example 1 is that, in order to prepare 1060 aluminum alloy bars, the flow ratio F of the hot rolling mill is fixed. n =0.85. The parameters of hot rolling process under this condition are shown in Table 5.

[0124]

[0125] Among them, each pass from 1 to 8 is driven by one motor; passes from 9 to 14 are driven by one motor, and different reduction ratios are used to control the motor speed and match the speed of each roller; passes from 15 to 22 are driven by one motor for two passes.

[0126] Performance testing:

[0127] The aluminum alloy bars actually prepared in the above examples and comparative examples were tested, and the results are shown in Table 6.

[0128] Grain boundary width: EBSD (electron backscatter diffraction) was used to analyze the grain morphology, and the intercept method was used according to GB / T 3246.1.

[0129] Area percentage of Brass texture, Copper texture, S texture, and Cube texture: automatically analyzed by EBSD software.

[0130] Differences between core and surface of grains: EBSD was used to analyze the grain morphology, and the intercept method was used for statistics with reference to GB / T 3246.1.

[0131] Elongation: GB / T 228 standard test.

[0132] Single roll weight: measured by electronic scale.

[0133] The tensile strength of the entire roll is extremely poor: GB / T 228 standard test.

[0134]

[0135] As can be seen, in Comparative Example 1, due to the excessively high flow rate ratio, the roller speed during rolling was far greater than the bar's ability to withstand tension, resulting in the bar breaking midway during hot rolling and preventing smooth forming. In Comparative Example 2, due to the 1060 alloy being a soft alloy, the flow rate ratio was too low during rolling, resulting in high compressive stress in the bar. This prevented smooth flow during rolling and caused the bar to overflow the roll gap, leading to bar stacking during hot rolling and preventing smooth forming.

[0136] The grain morphology of Example 1 of the present invention is shown in FIG. Figure 4 The grain morphology of comparative example 1 is shown in Figure 5 , the defect morphology of comparative example 1 is shown in Figure 6 . Figure 4 It can be seen that a small amount of dynamic recrystallization is formed in the rolling structure, which helps to increase the proportion of Cube texture, thereby improving the elongation and formability of the hot-rolled bar, providing a good foundation for subsequent cold forming, and the performance range of the finished material is relatively small. Figure 5 No obvious recrystallization is observed in the material. At this time, the Cube texture of the material accounts for a low proportion, the elongation is low, the forming performance is insufficient, and the performance of the finished material is extremely poor. Figure 6 It can be seen that the bars without reasonable rolling process adjustment show rolling fracture and middle holes.

[0137] The stacking defects caused by hot rolling in the digital model of comparative example 2 are shown in FIG. Figure 7 The morphology of stacking defects produced by hot rolling in actual production is shown in Figure 8 It can be seen that the material overflows the roll gap in the simulation process of comparative example 2, resulting in the easy formation of stacking in the subsequent rolling process. Figure 8 The actual rolling performance is consistent.

[0138] It can be seen from the above that, compared with the comparative example, the embodiments of the present invention establish a correlation between the parameters of the rolls in each pass in the aluminum alloy hot rolling mill, combine the inherent properties of soft aluminum alloy and hard aluminum alloy, confirm the flow rate ratio of the front and rear rolling passes of the rolls, and quickly obtain the motor speed of each roll suitable for the current rolling material through calculation. It can be directly applied to the actual hot rolling process, significantly improve the material forming quality and production efficiency, and reduce the cost of experimental exploration of parameters.

[0139] In addition, it can be seen that when all process parameters are within the preferred range of the present invention, the overall effect is better.

[0140] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A hot rolling method for aluminum alloy bars, characterized in that: The hot rolling method is carried out in a hot rolling mill and comprises the following steps: Step S1, preparing an aluminum alloy ingot from an aluminum ingot and a master alloy according to the composition ratio of the aluminum alloy bar; Step S2, determining the simulated motor speed ω of the n-th roller in the hot rolling process n ; Step S21, perform a three-dimensional scan on the hot rolling mill to obtain the nominal diameter D of each roll. n , the diameter of the inscribed circle of each roller wire d n , and obtain the reduction ratio k of each roller at the same time n The hole cross-sectional area S of the hot rolling mill is calculated by formula (1): n ; S n =π×d n 2 ÷4 (1); Step S22, according to the flow ratio F of the hot rolling mill n The flow rate L of the hot rolling mill is calculated by formula (2): n ; L n =L n-1 ×F n (2); where L n-1 The flow rate of the previous pass, L1 is 430000~440000mm 2 / s; Step S23, calculate the roller speed r of the hot rolling mill using formula (3): n , the simulated motor speed ω of the hot rolling mill is calculated by formula (4) n ; r n =L n ÷S n ÷(D n ÷2) (3); oh n =r n ×k n ×30÷π (4); Step S3, feeding the aluminum alloy ingot into the hot rolling mill, and rotating the aluminum alloy ingot at the simulated motor speed ω n As the actual motor speed, 1 to n hot rolling passes are performed to obtain the aluminum alloy bar; When the aluminum alloy bar is a soft aluminum alloy, the flow ratio is 0.95-1.10; When the aluminum alloy rod is a hard aluminum alloy, the flow ratio is 0.90-1.

05.

2. The hot rolling method according to claim 1, characterized in that The hard aluminum alloy includes one or more of 5xxx series aluminum alloy, 2xxx series aluminum alloy, 6xxx series aluminum alloy and 7xxx series aluminum alloy; and / or The soft aluminum alloy includes 1xxx series aluminum alloy.

3. The hot rolling method according to claim 1, characterized in that In the step S22, the flow ratio F of the hot rolling mill is determined according to the alloy series of the aluminum alloy bar. n ; When the alloy series of the aluminum alloy bar is 1xxx series aluminum alloy, F n 1.05~1.10; When the alloy series of the aluminum alloy bar is 2xxx series aluminum alloy, 6xxx series aluminum alloy or 7xxx series aluminum alloy, F n 0.95~1.05; When the alloy series of the aluminum alloy bar is 5xxx series aluminum alloy, F n It is 0.90~0.

95.

4. The hot rolling method according to claim 1, characterized in that After step S23, step S2 further includes the following steps: digitally modeling the hot rolling mill to obtain a digital model of the hot rolling mill; n The digital model of the hot rolling mill was run to obtain simulated aluminum alloy bars, and the forming state of the simulated aluminum alloy bars under the current conditions was visually observed: When the aluminum alloy simulated bar has no forming defects, the simulated motor speed ω n performing the hot rolling as the actual motor speed; When forming defects occur in the simulated aluminum alloy bar, repeating steps S22 and S23, adjusting the flow ratio until the simulated aluminum alloy bar no longer has forming defects, the motor speed at this time being the second simulated motor speed, and performing hot rolling with the second simulated motor speed as the actual motor speed; The forming defects include stacking, tensile fracture and opening cracking.

5. The hot rolling method according to claim 4, characterized in that When the aluminum alloy simulated bars are stacked, the flow ratio is adjusted to 1.05-1.10; When the aluminum alloy simulated bar exhibits the tensile fracture or the opening crack, the flow ratio is adjusted to 0.90-0.

95.

6. The hot rolling method according to claim 1, characterized in that In the step S1, the aluminum ingot and the master alloy are mixed according to the composition ratio of the aluminum alloy bar, and semi-continuous casting is performed to obtain an aluminum alloy cast bar; the aluminum alloy cast bar is sequentially subjected to homogenization heat treatment and milling to obtain the aluminum alloy ingot.

7. The hot rolling method according to claim 1, characterized in that The aluminum alloy bar has a grain boundary width of 15 to 30 μm, a total area percentage of Brass texture, Copper texture, and S texture of 10 to 30%, an area percentage of Cube texture of 50 to 70%, and a grain core-surface difference of ≤1.

0. The elongation of the aluminum alloy bar is 10-30%, and the range of tensile strength of the whole coil of 200-3000 kg is 2-15 MPa.

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