A method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer

Abstract

This invention discloses a method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer. The method includes a crystallizer corner treatment method and a casting process control method. The crystallizer corner treatment method includes the following steps: gap filling, applying a release agent, and assisted demolding. The casting process control method includes a casting speed control method, a cooling water control method, and a crystallizer liquid level control method. All three control methods include the following steps: a casting start-up stage and a stabilization stage. This method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer, by combining the crystallizer corner treatment method with a new casting process control method, forms a new production scheme. This not only reduces the tendency to crack but also reduces the probability of aluminum leakage and cold shut defects. Simultaneously, it improves the demolding ability of the aluminum alloy flat ingots, avoiding corner tearing and rolling surface tearing, thus improving the overall quality and yield of the aluminum alloy flat ingots.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy flat ingot casting technology, specifically a method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer. Background Technology

[0002] Alloy 5083 belongs to the Al-Mg series alloys and has high strength, good plasticity, corrosion resistance and machinability. It is widely used in automobiles, aircraft welded parts, subway and light rail, pressure vessels that require strict fire protection (such as liquid tank trucks, refrigerated trucks, refrigerated containers), etc., and is an important structural material.

[0003] Due to its structural characteristics, the adjustable crystallizer has a large surface and a small surface separated, and there will be gaps at the junction of the two surfaces. During the casting process, there is greater resistance to demolding at the corners, which can easily lead to corner tearing or even aluminum leakage. At the same time, because high-magnesium products have poor fluidity and poor demolding ability, they are prone to tearing of the rolling surface, especially in the unstable liquid cavity stage at the beginning of the machine. The surface shell is thinner, making it more likely to tear, leak aluminum, or even cracks and other abnormalities.

[0004] Because of its high magnesium content, deep liquid cavity, and high levels of manganese, as well as some copper and chromium, 5083 alloy is more thermally sensitive than other high-magnesium alloys. It is highly susceptible to hot cracking during casting, especially in large ingots. Warpage is also difficult to control, and excessive warpage leading to aluminum leakage is common. Most adjustable crystallizers used domestically are aluminum crystallizers, which have excessively strong primary cooling capacity. Lower liquid levels and speeds result in more cold shuts, which can easily cause cold shut cracks during secondary warpage.

[0005] Therefore, this application provides a method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer to solve the above-mentioned problems. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the existing defects and provide a method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer. By adopting a crystallizer corner treatment method combined with a new casting method and cooling method, a new production method is formed, which can not only reduce the tendency to crack, but also reduce the probability of aluminum leakage and cold shut defects. At the same time, it improves the demolding ability of aluminum alloy flat ingots and avoids corner tearing and rolling surface tearing. It can improve the overall quality of aluminum alloy flat ingots and effectively solve the problems in the background technology.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer, comprising a crystallizer corner treatment method and a casting process control method, wherein the crystallizer corner treatment method includes the following steps:

[0008] a1. Gap filling: Open the corner of the crystallizer, cut 1mm-3mm of fiber paper of appropriate size, add it to the gap for filling, and then tighten and cut flat;

[0009] a2. Apply release agent: Smooth the inner surface and corners of the crystallizer, and apply a 1-2mm thick layer of high-temperature resistant grease Kluber Metal Star 820 to assist in demolding;

[0010] a3. Assisted demolding: During the casting process, monitor the corners and promptly use a special dripping tool to drip high-viscosity crystallizer demolding lubricant to enhance lubrication if any abnormalities are found.

[0011] The casting process control methods include casting speed control methods, cooling water control methods, and crystallizer level control methods. The casting speed control method includes the following steps:

[0012] b1. Casting start stage: Casting is carried out using a medium-low speed casting method, with the casting speed maintained at 30-32 mm / min. The casting speed is gradually increased, and when the ingot length reaches 400-500 mm, the casting speed is increased to 55 mm / min.

[0013] b2. Stabilization stage: When the casting speed is increased to 55 mm / min, the casting is then carried out at this speed until the ingot casting is completed.

[0014] As a preferred technical solution of the present invention, the cooling water control method includes: low water flow rate during casting, that is, during the casting stage, the water flow rate is controlled at 10-13 m³ / h (water flow rate of a single crystallizer), and the water flow rate is slowly increased. When the water level reaches 450-550 mm (water flow rate of a single crystallizer), the water flow rate is slowly increased again, and when the water level reaches 450-550 mm, the water flow rate is increased to 60-65 m³ / h (water flow rate of a single crystallizer), and then cooling is continuously carried out at a water flow rate of 60-65 m³ / h (water flow rate of a single crystallizer).

[0015] As a preferred technical solution of the present invention, the crystallizer liquid level control method includes low liquid level casting. The initial liquid level is generally 45-50mm. As the ingot continues to descend, the ingot needs to maintain a higher liquid level (90-93mm) at a casting length of 180-280mm to compensate for the problem that the large aluminum liquid cannot cover the edge of the crystallizer at this position due to warping. The high liquid level is maintained for 100mm of casting length, and then it begins to descend. When the casting length reaches 500-600mm, a stable crystallizer liquid level height of 50-60mm is reached, and then this liquid level height is maintained until the end.

[0016] As a preferred technical solution of the present invention, the specific method of gap filling is as follows: First, open the safety pin and remove the finger screws. Then, open the flange connecting and adjusting the crystallizer with a ratchet wrench to separate the large surface and the small surface by a certain gap. Then, add the cut 1mm-3mm fiber paper to the gap between the large surface and the small surface for filling. After filling, close the flange again, insert the safety pin into the positioning hole, install the finger screws into the corresponding screw holes, and finally use a paper cutter to cut the exposed fiber paper flat.

[0017] As a preferred technical solution of the present invention, the oil dripping tool is manufactured as follows: First, a small hole is made at the top of a 500ml plastic bottle, and then a 20cm long Φ16 stainless steel round tube is fixed to the bottle cap by welding a nut, and the gap is sealed in place with sealant; before use, the bottle cap is opened and filled with crystallizer lubricating oil, and then the oil in the bottle is dripped into the inner wall of the crystallizer through the pipe by squeezing.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer, as exemplified by this invention, forms a new production scheme by combining a crystallizer corner treatment method with a new casting process control method. This not only reduces the tendency to crack, but also reduces the probability of aluminum leakage and cold shut defects. At the same time, it improves the demolding ability of aluminum alloy flat ingots, avoiding corner tearing and rolling surface tearing, and thus improving the overall quality of aluminum alloy flat ingots. Attached Figure Description

[0020] Figure 1 This is a flowchart of the crystallizer corner treatment method in this invention;

[0021] Figure 2 This is a flowchart of the casting process control method in this invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1-2 This invention provides a technical solution: a method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer, including a crystallizer corner treatment method and a casting process control method. The crystallizer corner treatment method includes the following steps:

[0024] a1. Gap filling: Open the corner of the crystallizer, cut 1mm-3mm of fiber paper of appropriate size, add it to the gap for filling, and then tighten and cut flat;

[0025] Specifically: The large and small faces of the adjustable crystallizer can be separated, mainly through a flange, the finger screws at the top, and the safety pin at the bottom. When filling the gap, first open the safety pin, remove the finger screws, and then use a ratchet wrench to open the flange connecting the crystallizer to adjust it, so that the large and small faces are separated by a certain gap. Then, add the 1mm-3mm cut fiber paper to the gap between the large and small faces for filling. After filling, close the flange again, then insert the safety pin into the positioning hole, install the finger screws into the corresponding screw holes, and finally use a utility knife to cut the exposed fiber paper flat.

[0026] a2. Apply release agent: Smooth the inner surface and corners of the crystallizer, and apply a 1-2mm thick layer of high-temperature resistant grease Kluber Metal Star 820 to assist in demolding;

[0027] a3. Assisted demolding: During the casting process, the corners are monitored, and if any abnormalities are found, a special dripping tool is used to assist in dripping high-viscosity crystallizer demolding lubricating oil to enhance lubrication.

[0028] Furthermore, the method for making the oil dripping tool is as follows: First, make a small hole at the top of a 500ml plastic bottle, then fix a 20cm long Φ16 stainless steel round tube to the bottle cap with a welding nut, and seal the gap with sealant; before use, open the bottle cap and fill it with crystallizer lubricating oil, and then squeeze the oil in the bottle through the tube onto the inner wall of the crystallizer.

[0029] Casting process control methods include casting speed control methods, cooling water control methods, and crystallizer level control methods. All three methods include a casting initiation stage and a stabilization stage. The casting speed control method includes the following steps:

[0030] b1. Casting start stage: Casting is carried out using a medium-low speed casting method, with the casting speed maintained at 30-32 mm / min. The casting speed is gradually increased, and when the ingot length reaches 400-500 mm, the casting speed is increased to 55 mm / min.

[0031] b2. Stabilization stage: When the casting speed is increased to 55 mm / min, the casting is then carried out at this speed until the ingot casting is completed.

[0032] Furthermore, the cooling water control method includes: low water flow rate during casting, that is, during the casting stage, the water flow rate is controlled at 10-13 m³ / h (single crystallizer water flow rate), and the water flow rate is slowly increased. When the water level reaches 450-550 mm, the water flow rate is increased to 60-65 m³ / h (single crystallizer water flow rate); subsequently, cooling is carried out continuously at a water flow rate of 60-65 m³ / h (single crystallizer water flow rate), and this stage is the stable stage.

[0033] Furthermore, the crystallizer level control method includes low-level casting start-up, i.e., the initial casting stage: the initial level is generally 45-50mm. As the ingot continues to descend and water cooling intensifies, the ingot will experience secondary warping at a casting length of 180-280mm. The warping at this position is relatively large, requiring a high level to compensate for the large warping and the problem that the molten aluminum cannot cover the edge of the crystallizer. Matching the molten aluminum height to 90-93mm can effectively compensate for the large shrinkage caused by warping, so that warping will not occur again after the secondary warping. However, the timing of the secondary warping is not easy to capture and is not very stable. Therefore, it is necessary to maintain a high level of about 100mm of casting length to avoid unstable aluminum leakage due to secondary warping. After maintaining a high level of about 100mm of casting length, the level then begins to drop, reaching a stable crystallizer level height of 50-60mm when the casting length reaches 500-600mm. This level is then maintained until the end, which is the stabilization stage.

[0034] Currently, traditional casting speeds of 35mm / min-40mm / min are commonly used for casting, which easily leads to cracking. Furthermore, lower casting speeds can cause cold shuts, which can cause stress concentration, especially during secondary warping, resulting in increased internal stress. Under the combined effect of these internal stresses, cold shut cracks are highly likely. To address this issue, this application uses a casting speed of 30-32mm / min, which is slower than traditional methods. This results in more stable aluminum ingot tail strength and less liquid, making the ingot tail less prone to tearing and reducing the probability of cracking. Then, the casting water flow rate and level are matched accordingly. At lower speeds, the water flow rate is slightly higher, but the water flow curve needs to be smoothed to match the lower casting speed. Although cold shuts may occur at the ingot tail, a sufficiently strong ingot tail can be created, reducing warping while preventing ingot tail collapse and cracking.

[0035] This invention employs a new crystallizer corner treatment method combined with a new casting and cooling method to form a new production method. This not only reduces the tendency to crack, but also reduces the probability of aluminum leakage and cold shut defects. At the same time, it improves the demolding ability of aluminum alloy flat ingots, avoiding corner tearing and rolling surface tearing. Overall, it can improve the quality and yield of aluminum alloy flat ingots.

[0036] All parts not disclosed in this invention are prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer, characterized in that: This includes methods for treating the corners of the crystallizer and methods for controlling the casting process. The methods for treating the corners of the crystallizer include the following steps: a1. Gap filling: Open the corner of the crystallizer, cut 1mm-3mm of fiber paper of appropriate size, add it to the gap for filling, and then tighten and cut flat; a2. Apply release agent: Smooth the inner surface and corners of the crystallizer, and apply a 1-2mm thick layer of high-temperature resistant grease Kluber Metal Star 820 to assist in demolding; a3. Assisted demolding: During the casting process, monitor the corners and promptly use a special dripping tool to drip high-viscosity crystallizer demolding lubricant to enhance lubrication if any abnormalities are found. The casting process control methods include casting speed control, cooling water control, and crystallizer liquid level control. Cooling water control methods include: low-flow-rate initial casting, where the water flow rate of a single crystallizer is controlled at 10-13 m³ / h during the initial casting stage, and the flow rate is slowly increased. When the water level reaches 450-550 mm, the water flow rate of a single crystallizer reaches 60-65 m³ / h, and subsequent single crystallizers are continuously cooled at a flow rate of 60-65 m³ / h. Crystallizer liquid level control methods include: low-level initial casting, where the initial liquid level is generally 45-50 mm. As the ingot continues to descend, a higher liquid level of 90-93 mm is required at a casting length of 180-280 mm to compensate for the large warping at this position and the problem of the aluminum liquid not covering the edge of the crystallizer. The high liquid level is maintained for 100 mm of casting length, and then the casting begins to descend, reaching a stable crystallizer liquid level height of 50-60 mm at a casting length of 500-600 mm, and then maintaining this liquid level height until the end. The casting speed control method includes the following steps: b1. Casting start stage: Casting is carried out using a medium-low speed casting method, with the casting speed maintained at 30-32 mm / min. The casting speed is gradually increased, and when the ingot length reaches 400-500 mm, the casting speed is increased to 55 mm / min. b2. Stabilization stage: When the casting speed is increased to 55 mm / min, the casting is then carried out at this speed until the ingot casting is completed.

2. The method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer according to claim 1, characterized in that: The specific method for filling the gaps is as follows: First, open the safety pin and remove the finger screws. Then, use a ratchet wrench to open the flange connecting the crystallizer to adjust it, allowing a certain gap to separate the large surface from the small surface. Then, add the 1mm-3mm cut fiber paper to the gap between the rolled surface and the small surface for filling. After filling, close the flange again, insert the safety pin into the positioning hole, install the finger screws into the corresponding screw holes, and finally use a paper cutter to cut the exposed fiber paper flat.

3. The method for producing 5083 aluminum alloy flat ingots using a domestically produced adjustable crystallizer according to claim 1, characterized in that: The method for making the oil dripping tool is as follows: First, make a small hole at the top of a 500ml plastic bottle, then fix a 20cm long Φ16 stainless steel round tube to the bottle cap with a welding nut, and seal the gap with sealant; before use, open the bottle cap and fill it with crystallizer lubricating oil, and then squeeze the oil in the bottle through the tube onto the inner wall of the crystallizer.

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