Rolling method for regulating and controlling micro-grain structure through wave-wedge synergistic effect lining plate

Abstract

The invention relates to a rolling method for regulating and controlling a micro-grain structure through a wave-wedge synergistic effect lining plate. The rolling method is used for solving the problems that when a plate is rolled and formed, the process is tedious, controllability is poor, the grain structure is disordered, and the finished product conversion rate is low. According to the controlled rolling method for the composite wave-shaped and wedge-shaped lining plate, the technology of the wave-shaped lining plate and the technology of the wedge-shaped lining plate are integrated, the lining plate with the complementary advantages is constructed, the hindering effect of external friction force on rolling deformation is reduced, the loading mode is converted into overall loading from local loading, a deformation area with the wider range and the more uniform effect is formed, and the rolling deformation is reduced. And meanwhile, the stress state of the plate in the rolling process is changed, grain structure morphology distribution is directionally regulated and controlled, the organization structure is optimized, improvement and collaborative improvement of the obdurability and ductility of the plate are promoted, and the quality and comprehensive performance of the rolled plate are remarkably improved. The microstructure of the formed plate is periodically distributed, and no obvious interface layer exists. The method is suitable for short-process rolling forming of high-performance metal plates.

Description

Technical Field

[0001] This invention relates to a method for rolling metal sheet liners, specifically a rolling method for controlling the microcrystalline structure of a liner with a wave-wedge synergistic effect, belonging to the field of sheet rolling forming technology. Background Technology

[0002] In modern industrial production, sheet metal possesses excellent mechanical and processing properties, making it widely used in various fields. Traditional sheet metal rolling technology can produce sheet metal of certain specifications, but it cannot meet user needs in many aspects. Liner rolling technology involves placing a liner material between the sheet metal and the rolls, and rolling the sheet metal through the interaction force between the liner and the rolls.

[0003] The limited selection of liner materials currently used restricts the applicability and versatility of liner rolling technology. Liners are easily consumed and require frequent replacement, increasing production costs and potentially causing production interruptions and impacting efficiency. Furthermore, ensuring the stability of the rolling process is difficult, making it challenging to control the quality and performance of the sheet metal. In current liner rolling technology, the contact pressure distribution between the liner and the sheet metal is uneven, leading to uneven sheet metal thickness and localized deformation, further complicating the quality and performance control of the sheet metal.

[0004] Further exploring the technical characteristics and potential of liner rolling and promoting the improvement of forming performance is an important direction for the research and development of high-performance metal sheet rolling technology. Summary of the Invention

[0005] The purpose of this invention is to address the bottleneck problems commonly encountered in the forming and manufacturing of mixed-grain structure metal sheets, such as complex preparation processes, high technological difficulty, poor controllability, disordered distribution of mixed grains, and susceptibility to defects. This invention proposes a rolling method for controlling the microcrystalline structure using a wave-wedge synergistic liner, resulting in the formation of high-performance metal sheets with a regularly distributed mixed-grain structure along the rolling direction. Specifically, the geometric dimensions of the wave-wedge synergistic liner are pre-designed based on the target metal sheet, ensuring differences in deformation across different parts of the sheet during rolling. The regularly distributed microcrystalline structure is controlled by designing the geometric features of the sheet along its length (diameter d of the wave surface, inclination angle α of the wedge surface, and proportionality coefficient γ). This method enables efficient and large-scale forming and manufacturing of high-performance metal sheets with a uniformly distributed mixed-grain structure.

[0006] This invention is achieved through the following technical solution:

[0007] Step 1: Prepare two inclined planes with length and width l2×w2 (l2>l1, w2>w1) and the same inclination angle α of the inclined planes, and a wave wedge synergistic plate for mechanical cutting;

[0008] Step 2: Smooth the upper and lower surfaces of the metal sheet and the beveled surface of the corrugated wedge liner, remove oil stains with alcohol, and then let it dry.

[0009] Step 3: Uniformly spray a high-temperature insulating agent (boron nitride) onto the contact surface between the two corrugated wedge synergistic lining plates and the metal sheet;

[0010] Step 4: Stack the upper wave wedge synergistic liner, metal sheet, and lower wave wedge synergistic liner in that order, with the metal sheet obliquely sandwiched between the two oblique surfaces of the upper and lower wave wedge synergistic liners, fixed with wire and leaving a slight movement gap;

[0011] Step 5: Adjust the heating furnace to the temperature required for rolling, place the binding assembly in the furnace for preheating, and hold for t.

[0012] Step Six: Adjust the mill reduction and roll speed;

[0013] Step 7: Driven by the rolling mill, the pusher blocks feed the metal sheet into the rolling mill. During rolling, the inclined surface of the liner plate and the metal sheet will slide slightly relative to each other along the contact surface.

[0014] Step 8: Perform intermediate annealing;

[0015] Step 9: The deformed metal sheet undergoes two-pass rolling deformation;

[0016] Step 10: After the metal sheet is air-cooled to room temperature, the edge material is removed on a shearing machine and then subjected to final annealing.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] I. Compared with traditional rolling, by introducing a wave-shaped and wedge-shaped combined liner, the stress state and deformation behavior of the metal sheet during rolling are changed, which alters the grain morphology and distribution. This results in a mixed-grain structure with weakly textured ultrafine / fine grains and strongly textured coarse grains, exhibiting significant differences in grain size. The significant mechanical incompatibility of different grain size regions alters the plastic deformation mechanism of the sheet, drives the activation of multiple deformation modes, and plays a role in coordinating the load deformation capacity of the sheet, thus significantly improving the plastic forming performance of the metal sheet.

[0019] 2. In the traditional rolling process, the deformation force and deformation path applied by the rolls to the metal sheet are singular, and the deformed grains are disordered and random. After adding a wave wedge liner, the rolled metal sheet forms a morphological structure with alternating distribution of grains of various sizes. The alternating distribution of coarse and fine grains increases the complexity and resistance of dislocation movement, thereby improving the material strength. The fine grain region effectively hinders dislocations due to the increased number and tortuosity of grain boundaries, while the coarse grain region provides more space for dislocation movement. This uneven dislocation distribution enhances the overall strength of the material.

[0020] Third, compared with conventional liner rolling, the wave wedge synergistic liner rolling process has three different motion modes due to the inclination angle α of the inclined surface. The motion can be controlled by the size of the inclination angle α. When the inclination angle α is larger, the relative slip between the wave wedge inclined surface of the liner and the metal sheet is greater. Under a smaller rolling pressure, a larger deformation of the sheet can be achieved, reducing the forming load and saving costs.

[0021] IV. After applying the soft wave wedge synergistic liner, the "biting force" between the liner and the metal sheet is significantly enhanced, the contact area is significantly increased, and the pressure per unit area is reduced, enabling single-pass large reduction rolling. Because the liner material is relatively soft and deforms first, it can adaptively adjust the distribution of force energy during rolling, resulting in more uniform deformation and stable structure of the metal sheet. This avoids the risk of excessive thinning or even cracking due to stress concentration in local areas, and the stability of sheet shape and quality are significantly improved simultaneously.

[0022] V. Under conventional rolling conditions, the magnitude and direction of the force exerted by the rolls on the liner remain unchanged, and the force transmitted from the liner to the metal sheet remains unchanged. After applying the liner with the synergistic action of the proportional wave wedge, the force transmitted from the liner to the metal sheet is continuously changed by adjusting the diameter d of the wave surface and the proportional coefficient γ. The deformation of each part also shows an increasing or decreasing trend. The continuous change of deformation of each part along the rolling direction causes the size of the micro-grain of the sheet to change in a gradient law, realizing the quantitative control of the microstructure and properties of homogeneous heterogeneous material, and achieving the improvement and synergistic enhancement of the strength, toughness and ductility of the sheet.

[0023] VI. Compared with the prior art, the present invention can achieve the forming and manufacturing of high-performance metal plates with microstructure control distribution by using only ordinary rolling mill and wave wedge liner for rolling deformation. It has the characteristics of short process flow, high production efficiency, simple operation and easy implementation. Attached Figure Description

[0024] Figure 1 Schematic diagram of the rolling principle of wave-wedge synergistic liner

[0025] Figure 2 Schematic diagram of the mechanical action of the wave-wedge synergistic liner

[0026] Figure 3 Schematic diagram of wave-wedge synergistic plate parameters

[0027] Figure 4 Process flow diagram

[0028] Figure 5 Schematic diagram of grain distribution in the rolling process of hard wedge synergistic liner

[0029] Figure 6 Schematic diagram of grain distribution during rolling of soft wave wedge synergistic liner

[0030] Figure 7 Schematic diagram of grain distribution in rolling of liner with equal-proportioned wave wedge synergy Specific implementation methods

[0031] Specific implementation method one: Combining Figure 1 , Figure 2 , Figure 3 , Figure 4 This implementation method includes an upper roll 1, an upper wedge-shaped liner 2, a metal sheet 3, a pusher block 4, a lower wedge-shaped liner 5, a lower roll 6, and the upper wedge-shaped liner and the sheet forming a sliding pair 2-3, and the lower wedge-shaped liner and the sheet forming a sliding pair 3-5. This implementation method is completed by the following steps: 1. Prepare a metal sheet with dimensions l1×w1 and thickness h1. The wedge-shaped inclined surfaces of the upper wedge-shaped liner 2 and the lower wedge-shaped liner 4 have dimensions l2×w2. The sliding friction coefficients of sliding pairs 2-3 and 3-5 are μ1 and μ2, respectively. Figure 1 As shown in Figures 2-3 and 3-5), the diameter d of the waveform surface and the tilt angle α ( Figure 2 1. Grind the contact surfaces of the metal sheet and the corrugated wedge liner, rinse the contact surfaces with alcohol, and let them dry. 2. Spray a high-temperature release agent (boron nitride) onto the contact surfaces of the metal sheet 3 and the upper and lower corrugated wedge liners 2 and 4 to prevent the liners from sticking to the sheet during rolling. 3. Stack the upper corrugated wedge liner, metal sheet, and lower corrugated wedge liner together in that order, fix them with wire, and leave a slight clearance. 4. Adjust the heating furnace to the required rolling temperature, and place the bonded assembly on... Preheating is performed in the furnace for a holding time of t; VI. Adjust the mill reduction and roll speed according to the rolling requirements of the target metal sheet; VII. Use pushers to feed the sheet into the mill. During the rolling process, the corrugated liner and the alloy sheet form a dynamic fit pair, and slight relative sliding occurs at the contact surface; VIII. After one rolling pass, the metal sheet undergoes intermediate annealing; IX. The deformed metal sheet undergoes a second rolling deformation; X. After the second rolling pass, the metal sheet is air-cooled to room temperature and then the edge material is removed on a shearing machine, followed by final annealing.

[0032] Specific implementation method two: Combining Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 This embodiment describes the design of the diameter d of the wave surface of the hard wave wedge synergistic liner and the inclination angle α of the wedge surface based on the process dimensions of the metal sheet. Under the same deformation scheme, the grains of the metal surface layer in region 1 are relatively refined, and region 2 forms a chain-like connection mode of large and small grains. The remaining steps are the same as in the specific implementation method one.

[0033] Specific implementation method three: Combining Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 This embodiment describes the design of the soft wave wedge synergistic liner with a diameter d and an inclination angle α based on the metal sheet process dimensions. Under the same deformation scheme, the metal surface layer grains in region 1 are relatively weakly refined, and region 2 forms a chain-like connection mode of large and small grains. The remaining steps are the same as in the specific implementation method one.

[0034] Specific implementation method four: Combining Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 7 This embodiment describes the design of a proportionally scaled wave wedge synergistic liner with diameter d for each wave surface, based on the metal sheet's process dimensions, to form a proportionally scaled waveform (d1 / d2=d2 / d3=γ). By adjusting the waveform diameter d and the proportionality coefficient γ, the grain structure arrangement of the regions is designed. Region 1 has strongly refined metal surface layer grains, Region 2 has weakly refined metal surface layer grains, and Region 3 forms a staggered grain layer connection pattern. The remaining steps are the same as in the first specific implementation method.

Claims

1. A rolling method for controlling micrograin structure using a wave-wedge synergistic liner, characterized in that... This is achieved through the following steps: Step 1: Prepare a metal sheet with dimensions l1×w1 and thickness h1. The wedge-shaped synergistic liner has dimensions l2×w2 (l2>l1, w2>w1), a waveform diameter d, and an inclination angle α (0°<α<90°). Step 2: Grind the surface of the metal sheet and the wedge-shaped synergistic liner, rinse the surface of the metal sheet with alcohol, and let it dry. Step 3: Spray a high-temperature release agent on the contact surfaces of the two wedge-shaped synergistic liners and the metal sheet. Step 4: Stack the upper wedge-shaped synergistic liner, the metal sheet, and the lower wedge-shaped synergistic liner together in that order, fix them with wire, and leave a slight movement gap. The metal sheet is obliquely sandwiched between the upper and lower wedge-shaped synergistic liners, with the upper liner in contact with the upper surface of the metal sheet. The sliding friction coefficient is μ1, and the sliding friction coefficient between the lower liner and the lower surface of the metal sheet is μ2, μ1≠μ2; Step 5: Adjust the heating furnace to the temperature required for rolling, place the binding assembly in the furnace for preheating, and hold for t; Step 6: Adjust the mill reduction and roll speed according to the rolling requirements of the target metal sheet; Step 7: Use push blocks to feed the sheet into the mill. During the rolling process, the liner and the metal sheet undergo plastic deformation together, and there will be slight relative sliding between their contact surfaces; Step 8: After one rolling pass, perform intermediate annealing on the metal sheet; Step 9: Perform a second rolling deformation on the deformed metal sheet; Step 10: After the second rolling pass, air cool the metal sheet to room temperature, then cut off the edge material on a shearing machine and perform final annealing.

2. The rolling method for controlling micrograin structure using a wave-wedge synergistic liner according to claim 1, characterized in that... The ability to roll metal sheets of various thicknesses, from thin to thick, requires l2 > l1 and d2 > d1. This ensures that the inclined surface of the wave-wedge synergistic liner completely covers the metal sheet and has a certain sliding allowance. During rolling, the relative displacement between the wave-wedge synergistic liner and the metal sheet is achieved, enabling the preparation of high-performance metal sheets.

3. The rolling method for controlling micrograin structure using a wave-wedge synergistic liner according to claim 1, characterized in that... The relative sliding amount between the metal sheet and the wave-wedge synergistic liner can be changed by adjusting the waveform diameter d and the slope angle α of the wedge surface under the same reduction. When the waveform diameter d and the slope angle α are different, the wave-wedge synergistic liner transmits forces of different directions and magnitudes, resulting in different deformations of the metal sheet during the rolling process. This allows for the directional control of grain structure distribution, enabling the preparation of high-performance metal sheets with different mixed-crystal structures.

4. The rolling method for controlling micrograin structure using a wave-wedge synergistic liner according to claim 1, characterized in that... By applying the synergistic effect of soft wave wedges in the rolling deformation, the soft liner undergoes plastic deformation before the plate when the roll applies pressure, which transmits pressure more evenly and efficiently, adaptively adjusts the stress field distribution, reduces the ineffective consumption of energy in local stress concentration areas, and avoids excessive thinning and cracking caused by stress concentration.

5. The rolling method for controlling micrograin structure using a wave-wedge synergistic liner according to claim 1, characterized in that... By adjusting the diameter d of each waveform surface to form a proportional waveform (d1 / d2=d2 / d3=γ), and by adjusting the diameter d of the waveform surface and the proportional coefficient γ, the upper and lower liner plates transmit complementary forces, thus preparing a metal plate with an asymmetric layered grain structure gradient. This achieves quantitative control of the microstructure and properties of the homogeneous heterogeneous material, thereby improving and synergistically enhancing the strength, toughness, and ductility of the plate.

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