Composite vibration continuous casting crystallizer and working method thereof

Abstract

The invention relates to the technical field of continuous casting, in particular to a composite vibration continuous casting crystallizer and a working method thereof. The composite vibration continuous casting crystallizer comprises a crystallizer body composed of wide-edge side walls and narrow-edge side walls, and the two oppositely-arranged wide-edge side walls and the two oppositely-arranged narrow-edge side walls jointly form a cavity for containing metal melt and generating a continuous casting billet. The wide-edge side wall is connected with the horizontal vibration device, the narrow-edge side wall is connected with the vertical vibration device, the wide-edge side wall vibrates in the horizontal direction during continuous casting, and the narrow-edge side wall vibrates in the vertical direction during continuous casting. According to the continuous casting crystallizer, a vibration mode combining horizontal vibration and vertical vibration is adopted, continuous casting billets with slight vibration marks or even no vibration marks can be obtained, meanwhile, a liquid casting powder channel is smooth, and the continuous casting billets in the crystallizer can be cooled more sufficiently and evenly.

Description

Technical Field

[0001] This invention relates to the field of continuous casting technology, and in particular to a composite vibration continuous casting crystallizer and its working method. Background Technology

[0002] The continuous casting crystallizer is the core component of the continuous casting machine. It is a device that conducts rapid heat exchange at high temperatures, which is equivalent to a highly efficient and continuously working mold. Its core function is to rapidly solidify the continuously injected liquid metal (such as molten steel) into a solid shell with a certain thickness and strength through forced cooling, and then continuously pull it out of the mold to form a casting billet of a specific shape.

[0003] During continuous casting, to prevent the billet shell from sticking to the mold wall, vibration and the addition of protective slag are needed to form a lubricating film between the billet shell and the mold wall. This reduces friction and allows the billet shell to periodically separate from the mold wall, preventing tearing caused by "sticking." Currently, continuous casting machines vibrate by driving the mold to move vertically up and down through a transmission device, creating relative motion between the mold wall and the billet shell to ensure the billet is pulled out continuously and smoothly. However, this vertical reciprocating motion creates regular "vibration marks" on the billet surface. These marks are sensitive areas for surface defects, and transverse cracks often occur at the root of these marks. Additionally, inclusions and bubbles tend to accumulate at the root of these marks. For high-quality steel billets, "skinning" is necessary before rolling; otherwise, the scrap rate of the rolled product is high. In addition, when using vertical reciprocating vibration, the channel for liquid protective slag to flow into the gap between the mold wall and the billet shell will become narrower. This can lead to insufficient filling of the gap between the billet shell and the mold wall by the protective slag, resulting in uneven heat transfer between the continuous casting billet and the mold, which can easily cause defects such as longitudinal cracks in the continuous casting billet.

[0004] Chinese patent application CN103317108A discloses a "method for controlling vibration marks on continuously cast billets." This method involves adding heat-insulating material to the inner or outer wall of the continuously cast mold at or above the meniscus to reduce heat transfer at this location, thereby weakening the initial solidification of the molten metal at the meniscus. The meniscus area refers to the sum of two lengths: 30-50 mm below the top surface of the molten metal and the length from the top surface of the molten metal to the top opening of the mold. However, this method merely shifts the location of vibration marks downwards, offering little relief and increasing the contact height between the molten metal and the mold several times over. This can easily lead to blockages in the flux descending channel, sticking, and leaking steel, resulting in serious accidents.

[0005] How to obtain continuously cast billets with slight or even no oscillation marks while maintaining unobstructed flow of liquid protective slag into the gap between the mold wall and the billet shell is a problem worthy of study and urgently needs to be solved. Summary of the Invention

[0006] This invention provides a composite vibration continuous casting crystallizer and its working method. It adopts a vibration mode that combines horizontal and vertical vibration, which can produce continuous casting billets with slight or even no vibration marks. At the same time, it can make the liquid protective slag channel unobstructed, so that the continuous casting billets in the crystallizer can be cooled more fully and evenly.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A composite vibration continuous casting crystallizer includes a crystallizer composed of wide sidewalls and narrow sidewalls. The two oppositely arranged wide sidewalls and the two oppositely arranged narrow sidewalls together form a cavity for containing molten metal and generating a continuously cast billet. The wide sidewalls are connected to a horizontal vibration device, and the narrow sidewalls are connected to a vertical vibration device. During continuous casting, the wide sidewalls vibrate in the horizontal direction, and the narrow sidewalls vibrate in the vertical direction.

[0009] The assembly gap between the wide sidewall and the narrow sidewall is less than 0.2 mm and is lubricated and sealed by lubricating oil.

[0010] Both the wide and narrow sidewalls are made of copper plates.

[0011] A method for operating a composite vibration continuous casting crystallizer includes the following steps:

[0012] 1) Connect the wide sidewall of the crystallizer to the horizontal vibration device, and connect the narrow sidewall of the crystallizer to the vertical vibration device;

[0013] 2) Both the wide and narrow sidewalls adopt a high-frequency, small-amplitude vibration mode, and the amplitude and vibration frequency of the wide and narrow sidewalls are set respectively;

[0014] 3) When casting begins, the horizontal and vertical vibration devices are started simultaneously. The wide sidewall vibrates back and forth in the horizontal direction, and the narrow sidewall vibrates back and forth in the vertical direction until casting is completed.

[0015] The horizontal vibration of the wide sidewall adopts a sinusoidal or non-sinusoidal vibration mode; the amplitude is 2-3 mm, and the vibration frequency is 200-400 times / min.

[0016] The vertical vibration of the narrow sidewall adopts a sinusoidal or non-sinusoidal vibration mode; the amplitude is 2-4 mm, and the frequency range is 200-300 times / min.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] (1) By adopting a vibration mode that combines horizontal and vertical vibration, continuous casting billets with slight or even no vibration marks on narrow sides can be obtained;

[0019] (2) The channel through which the liquid protective slag flows into the gap between the billet shell and the mold wall is always kept unobstructed, so that the continuous casting billet in the mold can be cooled more fully and evenly.

[0020] (3) The process is simple and easy to implement, safe and reliable, and has low investment and maintenance costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the composite vibration continuous casting crystallizer described in this invention.

[0022] Figure 2 This is a partial cross-sectional view of the composite vibration continuous casting crystallizer described in this invention.

[0023] In the diagram: 1. Wide sidewall 2. Narrow sidewall 3. Meniscus 4. Liquid protective slag 5. Cast billet shell Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0025] like Figure 1 As shown, the composite vibration continuous casting crystallizer of the present invention includes a crystallizer composed of a wide sidewall 1 and a narrow sidewall 2. The two oppositely arranged wide sidewalls 1 and the two oppositely arranged narrow sidewalls 2 together form a cavity for containing molten metal and generating a continuous casting billet. The wide sidewall 1 is connected to a horizontal vibration device, and the narrow sidewall 2 is connected to a vertical vibration device. During continuous casting, the wide sidewall 1 vibrates in the horizontal direction, and the narrow sidewall 2 vibrates in the vertical direction.

[0026] The assembly gap between the wide sidewall 1 and the narrow sidewall 2 is less than 0.2 mm and is lubricated and sealed by lubricating oil.

[0027] Both the wide sidewall 1 and the narrow sidewall 2 are made of copper plate.

[0028] The working method of the composite vibration continuous casting crystallizer of the present invention includes the following process:

[0029] 1) Connect the wide sidewall 1 of the crystallizer to the horizontal vibration device, and connect the narrow sidewall 2 of the crystallizer to the vertical vibration device;

[0030] 2) Both the wide sidewall 1 and the narrow sidewall 2 adopt a high-frequency, small-amplitude vibration mode, and the amplitude and vibration frequency of the wide sidewall 1 and the narrow sidewall 2 are set respectively;

[0031] 3) When casting begins, the horizontal and vertical vibration devices are started simultaneously. The wide sidewall 1 vibrates back and forth in the horizontal direction, and the narrow sidewall 2 vibrates back and forth in the vertical direction until casting is completed.

[0032] The horizontal vibration of the wide sidewall 1 adopts a sinusoidal or non-sinusoidal vibration mode; the amplitude is 2-3 mm, and the vibration frequency is 200-400 times / min.

[0033] The vertical vibration of the narrow sidewall 2 adopts a sinusoidal or non-sinusoidal vibration mode; the amplitude is 2-4 mm, and the frequency range is 200-300 times / min.

[0034] like Figure 2 As shown, vertical vibration produces a "negative slip" phenomenon, resulting in oscillation marks on the billet. Furthermore, the vertical movement of the crystallizer causes the channel for the downward flow of liquid protective slag 4 at the meniscus 3 to narrow twice during each cycle, leading to reduced consumption of liquid protective slag 4 and poor lubrication and heat transfer between the billet shell 5 and the crystallizer wall. Horizontal vibration, on the other hand, does not exhibit this "negative slip" phenomenon and therefore does not produce oscillation marks. Simultaneously, horizontal vibration helps maintain the unobstructed flow of liquid protective slag 4 into the gap between the crystallizer wall and the billet shell 5, resulting in superior lubrication and heat transfer between the billet shell 5 and the crystallizer compared to the traditional vertical vibration method.

[0035] The assembly gap between the wide sidewall 1 and the narrow sidewall 2 is less than 0.2 mm, and is lubricated and sealed with lubricating oil. Because of its cooling effect, no protective slag will seep in.

[0036] The composite vibration continuous casting crystallizer described in this invention produces a continuous casting billet with no vibration marks on the wide side; at the same time, because the molten metal is cooled sufficiently and uniformly in the crystallizer, there are no surface defects such as longitudinal cracks; the vibration marks on the narrow side are similar to those of continuous casting billets obtained by conventional vertical vibration.

[0037] To more intuitively illustrate the present invention, the embodiments of the present invention will be further described in conjunction with the examples. The following examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention, including simple variations or equivalent substitutions, are all within the scope of protection of the present invention.

[0038]

Example 1

[0039] This embodiment uses 16Mn steel continuously cast from slabs. The slab size is 1650mm × 230mm, and the casting speed is 1.6m / min. The operation process is as follows:

[0040] 1. Prepare the composite vibration continuous casting crystallizer of the present invention. The assembly gap between the wide sidewall and the narrow sidewall is 0.1 mm, and this assembly gap is lubricated and sealed by lubricating oil.

[0041] 2. Connect the wide sidewall of the crystallizer to the horizontal vibration device, and connect the narrow sidewall of the crystallizer to the vertical vibration device;

[0042] 3. Set the amplitude and vibration frequency of the wide sidewall to 2mm and 350Hz, respectively, and the amplitude and vibration frequency of the narrow sidewall to 4mm and 230Hz, respectively.

[0043] 4. When casting begins, the horizontal and vertical vibration devices are started simultaneously. The wide sidewalls vibrate back and forth in the horizontal direction, and the narrow sidewalls vibrate back and forth in the vertical direction until casting is completed.

[0044] The continuous casting billet obtained in this embodiment has no vibration marks or longitudinal cracks on its wide side, and the vibration marks on its narrow side are similar to those of the continuous casting billet obtained by conventional vertical vibration.

[0045] Upon inspection, the defect rate of transverse and longitudinal cracks in the continuously cast billet obtained in this embodiment was 0.016%, while the defect rate of transverse and longitudinal cracks in the continuously cast billet obtained using a traditional continuous casting mold was 5.0%, indicating a significant improvement in the quality of the continuously cast billet.

[0046]

Example 2

[0047] This embodiment uses slab continuous casting of high-alumina steel. The slab size is 1550mm × 200mm, and the casting speed is 1.0m / min. The operation process is as follows:

[0048] 1. Prepare the composite vibration continuous casting crystallizer of the present invention. The assembly gap between the wide sidewall and the narrow sidewall is 0.1 mm, and this assembly gap is lubricated and sealed by lubricating oil.

[0049] 2. Connect the wide sidewall of the crystallizer to the horizontal vibration device, and connect the narrow sidewall of the crystallizer to the vertical vibration device;

[0050] 3. Set the amplitude and vibration frequency of the wide sidewall to 2mm and 350Hz, respectively, and the amplitude and vibration frequency of the narrow sidewall to 4mm and 230Hz, respectively.

[0051] 4. When casting begins, the horizontal and vertical vibration devices are started simultaneously. The wide sidewalls vibrate back and forth in the horizontal direction, and the narrow sidewalls vibrate back and forth in the vertical direction until casting is completed.

[0052] The continuous casting billet obtained in this embodiment has no vibration marks or longitudinal cracks on its wide side, and the vibration marks on its narrow side are similar to those of the continuous casting billet obtained by conventional vertical vibration.

[0053] Upon inspection, the defect rate of transverse and longitudinal cracks in the continuously cast billet obtained in this embodiment was 0.02%, while the defect rate of transverse and longitudinal cracks in the continuously cast billet obtained using a traditional continuous casting mold was 5.2%, indicating a significant improvement in the quality of the continuously cast billet.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A composite vibration continuous casting mold, comprising a mold composed of wide-side walls and narrow-side walls, wherein two oppositely arranged wide-side walls and two oppositely arranged narrow-side walls together form a cavity for receiving molten metal and generating a continuously cast billet; characterized in that, The wide sidewall is connected to a horizontal vibration device, and the narrow sidewall is connected to a vertical vibration device. During continuous casting, the wide sidewall vibrates in the horizontal direction, and the narrow sidewall vibrates in the vertical direction.

2. The composite vibration continuous casting crystallizer according to claim 1, characterized in that, The assembly gap between the wide sidewall and the narrow sidewall is less than 0.2 mm and is lubricated and sealed by lubricating oil.

3. The composite vibration continuous casting crystallizer according to claim 1, characterized in that, Both the wide and narrow sidewalls are made of copper plates.

4. A method for operating a composite vibration continuous casting crystallizer as described in any one of claims 1 to 3, characterized in that, The process includes the following: 1) Connect the wide sidewall of the crystallizer to the horizontal vibration device, and connect the narrow sidewall of the crystallizer to the vertical vibration device; 2) Both the wide and narrow sidewalls adopt a high-frequency, small-amplitude vibration mode, and the amplitude and vibration frequency of the wide and narrow sidewalls are set respectively; 3) When casting begins, the horizontal and vertical vibration devices are started simultaneously. The wide sidewall vibrates back and forth in the horizontal direction, and the narrow sidewall vibrates back and forth in the vertical direction until casting is completed.

5. The working method of a composite vibration continuous casting crystallizer according to claim 4, characterized in that, The horizontal vibration of the wide sidewall adopts a sinusoidal or non-sinusoidal vibration mode; the amplitude is 2-3 mm, and the vibration frequency is 200-400 times / min.

6. The working method of a composite vibration continuous casting crystallizer according to claim 4, characterized in that, The vertical vibration of the narrow sidewall adopts a sinusoidal or non-sinusoidal vibration mode; the amplitude is 2-4 mm, and the frequency range is 200-300 times / min.

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