A light alloy multistage quenching device and a method of using the same

Abstract

The application provides a light alloy multistage quenching device and a use method thereof, which comprises a first quenching zone, a second quenching zone and a third quenching zone, each quenching zone comprises a roller, a transverse pressing mechanism arranged transversely and a vertical pressing mechanism arranged vertically, the roller, the transverse pressing mechanism and the vertical pressing mechanism are used as separating components to separate the periphery of a workpiece into four independent fan-shaped spaces in a circumferential direction, and a spraying system is arranged in each fan-shaped space. When the workpiece enters the quenching zone from the front end, the spraying system of the quenching zone is controlled to work and spray according to a preset flow value, so that the quenching of the workpiece is realized, and in the spraying process, liquid located above the transverse pressing mechanism flows to the inner recess area on the partition plate. The scheme of the application can not only realize the rapid quenching of large light alloy profiles, greatly improve the strength and elongation of the light alloy profiles after aging, but also effectively prevent the light alloy from cracking during quenching.

Description

Technical Field

[0001] This invention belongs to the field of light alloy (aluminum / magnesium alloy) profile preparation technology, specifically relating to a light alloy multi-stage quenching device and its usage method. Background Technology

[0002] Compared to cast light alloys, wrought light alloys have finer grains and eliminate casting defects, resulting in significantly improved overall mechanical properties. With the expanding applications of light alloys, the demand for large-format profiles is increasing. However, if not cooled after extrusion or forging, the slow cooling process leads to significant precipitation of the second phase, reducing its strength and toughness. Traditional immersion and spray quenching methods often result in quenching cracks. Therefore, given the shortcomings of existing quenching processes, there is an urgent need for a new quenching technology for light alloys.

[0003] In the prior art, document CN105755230B discloses an integrated quenching-aging device for magnesium alloys, comprising a hot air quenching device, a hot medium quenching device, and a hot medium aging device connected sequentially via a transmission device. The hot air quenching device includes a housing and a track for conveying magnesium alloy materials, with several hot air injection holes on the side wall of the housing. The hot medium quenching device includes a quenching medium tank and a hollow rotating disk located within the tank, with several spaces on the rotating disk for accommodating magnesium alloy materials. The track of the hot air quenching device extends to a position corresponding to the space in the hot medium aging device used to accommodate magnesium alloy materials, and the transfer of magnesium alloy materials is achieved by a push rod. In this scheme, although the two-stage quenching technique is adopted, it can reduce the quenching cracking efficiency of magnesium alloys when applied to magnesium alloys with a cross-sectional size of 250 mm * 150 mm. However, when applied to round magnesium alloy profiles with a cross-sectional size of not less than 400 mm and a wall thickness greater than 250 mm or less than 50 mm, the problem of high quenching cracking efficiency still exists. In particular, quenching cracking is prone to occur in the arc-shaped area of ​​1 / 6 of the circumference on both sides of the lowest point of the magnesium alloy profile cross-section when placed horizontally. Summary of the Invention

[0004] At least in order to solve the technical problems mentioned in the background art, the present invention aims to provide a multi-stage quenching device for light alloys and its method of use.

[0005] The present invention adopts the following technical solution.

[0006] A multi-stage quenching device for light alloys includes a roller-type conveyor track for transferring workpieces, and three quenching zones arranged at intervals. Each quenching zone includes horizontally arranged rollers, two transversely arranged transverse pressing mechanisms, and a vertically arranged vertical pressing mechanism. The rollers, transverse pressing mechanisms, and vertical pressing mechanisms are used as dividing components to divide the periphery of the workpiece into four independent fan-shaped spaces along the circumferential direction. A spraying system is arranged in each fan-shaped space, and all spraying systems together form an annular spraying zone surrounding the workpiece.

[0007] To better prevent quenching cracks, the transverse pressing mechanism includes a transverse displacement mechanism. A partition is fixedly connected to the displacement component of the transverse displacement mechanism. A high-temperature resistant flexible sealing element is provided at the front end of the partition. An indented area is provided on the partition and near the front end of the partition. When the displacement component moves laterally to the target position, the flexible sealing element at the front end of the partition presses against the side wall of the workpiece.

[0008] To better prevent quenching cracks, the partition is arranged at an angle of 0 to 10° to the horizontal plane, so that the partition is slightly tilted.

[0009] Preferably, the concave region has an arc-shaped cross-section.

[0010] Preferably, the vertical pressing mechanism includes a cylinder, the lower end of the cylinder's telescopic rod is connected to a baffle, and the lower section of the baffle is covered with a rubber strip.

[0011] Preferably, the lower end of the cylinder's telescopic rod is connected to a baffle via a movable part. The movable part is a cylindrical body with an opening, and the baffle extends into the cylindrical body from the opening and can slide up and down along the cylindrical body.

[0012] To better prevent quenching cracks and improve the strength and elongation of the light alloy profiles, the length of the first quenching zone is 1.5±0.1m. In the spray system of the first quenching zone, any two adjacent nozzles are spaced 20mm apart, and the spray holes consist of three micro-holes with a diameter of 0.5mm. The length of the second quenching zone is 2±0.1m. In the spray system of the second quenching zone, any two adjacent nozzles are spaced 30mm apart, and the spray holes consist of three small holes with a diameter of 1.5mm. The length of the third quenching zone is 3±0.2m. In the spray system of the third quenching zone, any two adjacent nozzles are spaced 50mm apart, and the spray holes consist of three small holes with a diameter of 3mm.

[0013] A method of using the aforementioned multi-stage quenching device for light alloys, comprising the following steps:

[0014] Step 1: Control the operation of the roller conveyor track to make the workpiece move forward at a constant speed;

[0015] Step 2: When the front section of the workpiece just enters the quenching zone, control the displacement component of the transverse displacement mechanism to move to the first target position, so that the flexible sealing element at the front end of the baffle is pressed against the side wall of the workpiece; at the same time, control the cylinder to move its lower end of the telescopic rod to the second target position, at which time the rubber strip at the lower end of the baffle is against the top wall of the workpiece.

[0016] Step 3: When the front end of the workpiece enters the quenching zone, control the spraying system of the quenching zone to work and spray according to the preset flow rate to achieve quenching of the workpiece. During the spraying process, the liquid above the transverse pressing mechanism flows to the concave area on the partition plate.

[0017] Step 4: When the tail end of the workpiece leaves the quenching zone, control the spray system of the quenching zone to stop, and control the displacement component and the telescopic rod of the cylinder to reset.

[0018] Furthermore, a strong wind quenching zone is set up before the first quenching zone. Before entering the first quenching zone, the workpiece is cooled by the strong wind quenching zone. The air temperature is room temperature and the air flow rate is controlled at 18~22L / s.

[0019] Beneficial effects: The solution of this invention not only enables rapid quenching of large light alloy profiles, significantly improving their strength and elongation after aging, but also effectively prevents quenching cracks, particularly circular light alloy profiles with cross-sectional dimensions of not less than 400mm, wall thickness greater than 300mm, and wall thickness less than 50mm. It also avoids the problem of uneven quenching that easily occurs during online quenching. The solution of this invention uses simple equipment, has a simple process operation, low cost, and can achieve continuous large-scale industrial production. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of the multi-stage quenching device for light alloys in Example 1;

[0021] Figure 2 This is a schematic diagram of the main direction of the multi-stage quenching device for light alloys in Example 1;

[0022] Figure 3 This is a top-down schematic diagram of the multi-stage quenching device for light alloys in Example 1;

[0023] Figure 4 This is a schematic diagram of a single quenching zone in the multi-stage quenching device for light alloys in Example 1;

[0024] Figure 5 This is a schematic cross-sectional view of the multi-stage quenching device for light alloys in Example 1;

[0025] Figure 6 This is a cross-sectional schematic diagram of the multi-stage quenching device for light alloys in Example 2;

[0026] Figure 7 This is a schematic diagram of the cross-section of a magnesium alloy profile. Detailed Implementation

[0027] The technical solutions 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. Example 1

[0028] Combination Figures 1 to 5 As shown, a multi-stage quenching device for light alloys includes a roller-type conveyor track for transferring workpiece 4, and three quenching zones 1, 2, and 3 arranged at intervals. Each quenching zone includes horizontally arranged rollers 5, two laterally arranged transverse pressing mechanisms 6, and a vertically arranged vertical pressing mechanism 7. The rollers 5, transverse pressing mechanisms 6, and vertical pressing mechanism 7 serve as dividing components, dividing the periphery of workpiece 4 into four independent fan-shaped spaces along the circumferential direction. A spray system 8 is arranged in each fan-shaped space, and all spray systems 8 together form an annular spray area surrounding workpiece 4. Figure 5 As shown, a first spray system 84 is arranged in the fan-shaped space between the right horizontal pressing mechanism 6 and the vertical pressing mechanism 7, a second spray system 81 is arranged in the fan-shaped space between the left horizontal pressing mechanism 6 and the vertical pressing mechanism 7, a third spray system 82 is arranged in the fan-shaped space between the left horizontal pressing mechanism 6 and the roller 5, and a fourth spray system 83 is arranged in the fan-shaped space between the right horizontal pressing mechanism 6 and the roller 5.

[0029] In this embodiment, the lateral pressing mechanism 6 includes a lateral displacement mechanism, which is a cylinder. A partition 10 is fixedly connected to the displacement member 13 (the telescopic rod of the cylinder) of the lateral displacement mechanism. A high-temperature resistant flexible sealing element 11 is provided at the front end of the partition 10. An inner recess 12 is provided on the partition 10 and near the front end of the partition 10. The cross-section of the inner recess 12 is arc-shaped. The partition 10 forms a 0° angle with the horizontal plane. When the displacement member 13 moves laterally to the target position, the flexible sealing element 11 at the front end of the partition 10 abuts against the side wall of the workpiece 4. The spray system 8 is installed on the inner side wall of the cylindrical shell 20. Gaps are provided on both the left and right sides of the cylindrical shell 20, and the partition 10 can flexibly pass through the gaps and extend into the inner cavity of the cylindrical shell 20.

[0030] In this embodiment, the vertical pressing mechanism 7 includes a cylinder 14. The lower end of the telescopic rod of the cylinder 14 is connected to a baffle 15. The lower section of the baffle 15 is covered with a rubber strip 16. A gap is also provided at the top of the cylindrical shell 20. The baffle 15 can flexibly pass through the gap and extend into the inner cavity of the cylindrical shell 20. The rubber strip 16, the flexible sealing element 11 and the roller 5 together form a space to accommodate the radial section of the workpiece 4.

[0031] In this embodiment, the first quenching zone 1 is 1.5m long. In the spray system 8 of the first quenching zone 1, any two adjacent nozzles are spaced 20mm apart, and the spray holes consist of three micro-holes with a diameter of 0.5mm. The second quenching zone 2 is 2m long. In the spray system 8 of the second quenching zone 2, any two adjacent nozzles are spaced 30mm apart, and the spray holes consist of three small holes with a diameter of 1.5mm. The third quenching zone 3 is 3m long. In the spray system 8 of the third quenching zone 3, any two adjacent nozzles are spaced 50mm apart, and the spray holes consist of three small holes with a diameter of 3mm. A strong wind quenching zone is set before the first quenching zone 1. Before entering the first quenching zone 1, the workpiece 4 is cooled by strong wind at room temperature and the airflow rate is controlled at 18~22L / s.

[0032] A method for using a multi-stage quenching device for a light alloy (magnesium alloy, grade VW83M) in this embodiment includes the following steps:

[0033] Step 1: Control the operation of the roller conveyor track to make workpiece 4 move forward at a uniform speed;

[0034] Before entering the first quenching zone 1, workpiece 4 is cooled in the strong wind quenching zone. The wind temperature is room temperature and the air flow rate is controlled at 20L / s.

[0035] Step 2: When the front section of workpiece 4 just enters the first quenching zone 1, the displacement component 13 of the transverse displacement mechanism is controlled to move to the first target position, so that the flexible sealing element 11 at the front end of the partition 10 presses against the side wall of workpiece 4; at the same time, the cylinder 14 is controlled to move its lower end of the telescopic rod to the second target position. At this time, the rubber strip 16 at the lower end of the baffle 15 is attached to the top wall of workpiece 4.

[0036] Step 3: When the front end of the workpiece 4 enters the first quenching zone 1, the spraying system 8 of the quenching zone is controlled to work and spray according to the preset flow rate value to achieve quenching of the workpiece 4. During the spraying process, the liquid above the transverse pressing mechanism 6 flows to the concave area 12 on the partition plate 10.

[0037] During use, when any part of the workpiece 4 enters the first quenching zone 1, the spray system 8 of the first quenching zone 1 sprays moisture (wet mist) at a specified temperature and flow rate onto the surface of the workpiece 4; when any part of the workpiece 4 enters the second quenching zone 2, the spray system 8 of the second quenching zone 2 sprays quenching liquid one at a specified temperature and flow rate onto the surface of the workpiece 4; when any part of the workpiece 4 enters the third quenching zone 3, the spray system 8 of the third quenching zone 3 sprays quenching liquid two at a specified temperature and flow rate onto the surface of the workpiece 4.

[0038] Step 4: When the tail end of workpiece 4 leaves the third quenching zone 3, control the spray system 8 of the quenching zone to stop, and control the telescopic rods of displacement component 13 and cylinder 14 to reset.

[0039] In this embodiment, whether it is the moisture (wet fog) quenching in the first quenching zone 1 or the spray quenching in the second quenching zone 2 and the third quenching zone 3, the problem of local accumulation / excessive quenching medium is avoided, and the quenching effect is significantly optimized. Example 2

[0040] A multi-stage quenching device for light alloys, referring to Example 1, differs from Example 1 mainly in that: [The following text appears to be incomplete and requires further context: "combining..."] Figure 6 As shown, the lower end of the telescopic rod of cylinder 14 is connected to baffle 15 via movable member 17. Movable member 17 is a cylindrical body with an opening, and baffle 15 extends into the cylindrical body from the opening and can slide up and down along the cylindrical body. In this embodiment, movable member 17 can be understood as a telescopic cylinder connected to the lower end of telescopic rod, and baffle 15 can be understood as a sliding rod that fits in the inner cavity of telescopic cylinder. When the telescopic rod of cylinder 14 retracts, it drives movable member 17 and baffle 15 to move upward; when the telescopic rod of cylinder 14 extends, it drives movable member 17 and baffle 15 to move downward, and baffle 15 will also move downward a distance along movable member 17 under the action of gravity. Example 3

[0041] A multi-stage quenching device for light alloys, referring to Embodiment 1, differs from Embodiment 1 mainly in that the partition 10 forms an angle of 5-10° with the horizontal plane, allowing the partition 10 to be arranged slightly inclined. In this embodiment, a more significant advantage compared to the embodiment is that it can prevent quenching fluid from accumulating at the angle between the flexible sealing element 11 and the workpiece 4, and can better prevent localized quenching cracks in the light alloy profile caused by accumulated quenching fluid within a short period. Example 4

[0042] A multi-stage quenching device for light alloys, referring to Embodiment 1, differs from Embodiment 1 mainly in that: a lead screw translation mechanism is used instead of the lateral displacement mechanism in Embodiment 1, and the nut seat of the lead screw translation mechanism serves as the displacement element 13.

[0043] Comparative Example 1: Spray quenching, specifically, several nozzles are arranged at intervals on a ring support, with the nozzles facing the axis of the ring support, and the workpiece passes axially through the middle of the ring support.

[0044] Comparative Example 2: Immersion quenching, specifically, the workpiece is placed in a quenching bath.

[0045] Comparative Example 3 (essentially the same scheme as the central solution in document CN105755230B): hot air quenching combined with hot medium quenching, specifically, hot air is first introduced to flow over the surface of the workpiece, and then the workpiece is moved to the spray system for spraying.

[0046] Comparative Example 4: Referring to Example 1, the difference between Example 1 and Example 4 is that the two horizontally arranged horizontal pressing mechanisms 6 and the one vertically arranged vertical pressing mechanism 7 are omitted.

[0047] Performance testing: The methods in Example 1 and the comparative example were used to test the magnesium alloy profile (grade VW83M). Figure 7 As shown, the sample (outer diameter 451mm, inner diameter 181mm, length 2200mm) was quenched and subjected to crack detection (detection locations are shown in [reference]). Figure 7 The light-colored area (the arc-shaped area extending 1 / 6 of the circumference from the lowest point on both sides of the magnesium alloy profile section) is shown in Table 1 below.

[0048] Table 1 Quenching conditions of magnesium alloy profiles

[0049]

[0050] The solution adopted in this embodiment not only enables rapid quenching of large magnesium alloy profiles, significantly improving their strength and elongation after aging, but also effectively prevents quenching cracks, particularly for round magnesium alloy profiles with cross-sectional dimensions of not less than 400mm, wall thickness greater than 300mm, and wall thickness less than 50mm. It also avoids the problem of uneven quenching that easily occurs during online quenching. This solution uses simple equipment, involves simple processes, is low-cost, and can achieve continuous large-scale industrial production.

Claims

1. A multi-stage quenching device for light alloys, comprising a roller-type conveyor track for transferring workpieces (4), characterized in that: It also includes a first quenching zone (1), a second quenching zone (2), and a third quenching zone (3) arranged at intervals. Each quenching zone includes horizontally arranged rollers (5), two transversely arranged transverse pressing mechanisms (6), and a vertically arranged vertical pressing mechanism (7). The rollers (5), transverse pressing mechanisms (6), and vertical pressing mechanisms (7) are used as dividing components to divide the workpiece (4) into four independent fan-shaped spaces along the circumferential direction. A spray system (8) is arranged in each fan-shaped space. All the spray systems (8) together form a circular spray area around the workpiece (4); transverse pressing... The mechanism (6) includes a lateral displacement mechanism. A partition (10) is fixedly connected to the displacement component (13) of the lateral displacement mechanism. A high-temperature resistant flexible sealing element (11) is provided at the front end of the partition (10). An indented area (12) is provided on the partition (10) and near the front end of the partition (10). When the displacement component (13) moves laterally to the target position, the flexible sealing element (11) at the front end of the partition (10) presses against the side wall of the workpiece (4). The vertical pressing mechanism (7) includes a cylinder (14). The lower end of the telescopic rod of the cylinder (14) is connected to a baffle (15). The lower section of the baffle (15) is covered with a rubber strip (16).

2. The multi-stage quenching device for light alloys according to claim 1, characterized in that: The partition (10) is at an angle of 5 to 10° to the horizontal plane so that the partition (10) is arranged slightly at an angle.

3. The multi-stage quenching device for light alloys according to claim 2, characterized in that: The concave region (12) has an arc-shaped cross-section.

4. The multi-stage quenching device for light alloys according to claim 3, characterized in that: The lower end of the telescopic rod of the cylinder (14) is connected to the baffle (15) through the movable part (17). The movable part (17) adopts a cylinder with an opening. The baffle (15) extends into the cylinder from the opening and can slide up and down along the cylinder.

5. The multi-stage quenching apparatus for light alloys according to any one of claims 1-4, characterized in that: The length of the first quenching zone (1) is 1.5±0.1m. In the spray system (8) of the first quenching zone (1), any two adjacent nozzles are spaced 20mm apart, and the spray hole is composed of three micro-holes with a diameter of 0.5mm. The length of the second quenching zone (2) is 2±0.1m. In the spray system (8) of the second quenching zone (2), any two adjacent nozzles are spaced 30mm apart, and the spray hole is composed of three small holes with a diameter of 1.5mm. The length of the third quenching zone (3) is 3±0.2m. In the spray system (8) of the third quenching zone (3), any two adjacent nozzles are spaced 50mm apart, and the spray hole is composed of three small holes with a diameter of 3mm.

6. A method of using the multi-stage quenching apparatus for light alloys as described in any one of claims 1-5, characterized in that the step include: Step 1: Control the operation of the roller conveyor track to make the workpiece (4) move forward at a uniform speed; Step 2: When the front section of the workpiece (4) just enters the quenching zone, the displacement component (13) of the transverse displacement mechanism is controlled to move to the first target position, so that the flexible sealing element (11) at the front end of the partition (10) is pressed against the side wall of the workpiece (4); at the same time, the cylinder (14) is controlled to move its lower end of the telescopic rod to the second target position. At this time, the rubber strip (16) at the lower end of the baffle (15) is against the top wall of the workpiece (4). Step 3: When the front end of the workpiece (4) enters the quenching zone, control the spraying system (8) of the quenching zone to work and spray according to the preset flow rate value to achieve quenching of the workpiece (4). During the spraying process, the liquid above the transverse pressing mechanism (6) flows to the concave area (12) on the partition plate (10). Step 4: When the tail end of the workpiece (4) leaves the quenching zone, control the spray system (8) of the quenching zone to stop, and control the displacement component (13) and the telescopic rod of the cylinder (14) to reset.

7. The method of use according to claim 6, characterized in that: A strong wind quenching zone is set up before the first quenching zone (1). Before the workpiece (4) enters the first quenching zone (1), it is cooled by strong wind. The wind temperature is room temperature and the air flow rate is controlled at 18~22L / s.

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