Electroslag welding apparatus and method of welding

Abstract

This invention provides an electroslag welding apparatus and a welding method thereof. The electroslag welding apparatus includes a workpiece body and a power source. A slag pool is disposed within the workpiece body, and a molten pool is disposed below the slag pool. Metal slag in the slag pool accumulates below the molten pool after passing through it, forming a weld. A liquid-cooled forming slider is disposed around the periphery of the molten pool. The height of the molten pool increases with the accumulation of the weld, and the height of the liquid-cooled forming slider also increases with the molten pool. Furthermore, a first conductive path is provided between the slag pool and the positive electrode of the power source, a second conductive path is provided between the weld and the negative electrode of the power source, and a third conductive path is provided between the liquid-cooled forming slider and the negative electrode. The electroslag welding apparatus provided by this invention can solve the problem of poor weld formation quality in the prior art.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and more specifically, to an electroslag welding apparatus and its welding method. Background Technology

[0002] Traditional electroslag welding has only one current loop, with the current path being: power source - molten nozzle / steel pipe - slag pool - molten metal pool - weld - workpiece - power source. Generally, to ensure the surface quality of the electroslag weld, a larger current and higher melting rate are required for smelting. This method results in a deeper molten metal pool, and the liquid-cooled forming slide block has limited cooling capacity for the weld center. Therefore, it easily leads to increased local solidification time at the weld solidification front, faster slag pool rise, and shorter heat diffusion time. Simultaneously, it can cause incomplete fusion and slag inclusions, resulting in insufficient melting at the base metal edges and an incomplete weld formation.

[0003] Conversely, if a smaller current and a lower melting rate are used, although a shallower and flatter molten pool can be obtained, reducing the degree of component segregation in the weld, the amount of slag on the liquid-cooled forming slider may be insufficient, resulting in a thicker slag layer and even surface quality defects such as slag grooves and ripples in the weld.

[0004] Based on the above technical problems, there is an urgent need for a solution that can ensure both weld formation and the quality of the weld surface and interior. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide an electroslag welding apparatus and welding method therein to solve the problem of poor weld formation quality in the prior art.

[0006] This invention provides an electroslag welding apparatus, including a workpiece body and a power source. A slag pool is disposed within the workpiece body, and a molten pool is disposed below the slag pool. Metal slag in the slag pool accumulates below the molten pool after passing through it, forming a weld. A liquid-cooled forming slider is disposed around the periphery of the molten pool. The height of the molten pool increases with the accumulation of the weld, and the height of the liquid-cooled forming slider also increases with the molten pool.

[0007] A first conductive path is provided between the slag pool and the positive terminal of the power supply, a second conductive path is provided between the weld and the negative terminal of the power supply, and a third conductive path is provided between the liquid-cooled forming slider and the negative terminal.

[0008] Furthermore, a preferred embodiment is to provide a first switch on the first conductive path, a second switch on the second conductive path, and a third switch on the third conductive path.

[0009] Furthermore, a preferred embodiment is to provide a first ammeter in the first conductive path, a second ammeter in the second conductive path, and a third ammeter in the third conductive path.

[0010] Furthermore, a preferred embodiment is that the liquid-cooled forming slider is filled with circulating coolant; and,

[0011] The liquid-cooled molding slider is provided with a liquid inlet and a liquid outlet, and the liquid-cooled molding slider is connected to an external liquid supply device through the liquid inlet and the liquid outlet.

[0012] Furthermore, a preferred embodiment is to provide an adjustable resistor within the liquid-cooled forming slider, which is connected between the molten pool and the third conductive path.

[0013] Furthermore, in a preferred embodiment, the circulating coolant forms the adjustable resistor; and,

[0014] The volume and flow rate of the circulating coolant are adjusted by means of the liquid supply device in conjunction with the liquid inlet and the liquid outlet, thereby adjusting the resistance value of the adjustable resistor.

[0015] Furthermore, a preferred embodiment is that a melting nozzle tube is provided inside the slag hole of the slag pool, and the slag pool is connected to the first conductive path through the melting nozzle tube.

[0016] Furthermore, a preferred embodiment is that a welding wire is provided inside the fusion nozzle tube.

[0017] In addition, a preferred embodiment is to provide a weld initiation groove at the bottom of the workpiece body, and the weld seam is formed by accumulation within the weld initiation groove.

[0018] On the other hand, the present invention also provides a welding method for the aforementioned electroslag welding apparatus, the welding method comprising:

[0019] Turn on the power supply, close the first switch and the second switch, and after the power is applied to start the arc and slag formation, the weld begins to form in the weld initiation groove. The molten pool begins to rise as the weld accumulates, and the liquid-cooled forming slider begins to move upward with the molten pool.

[0020] Close the third switch to form a first circuit and a second circuit; wherein, the first circuit includes, in sequence, the positive terminal of the power supply, a first conductive path, a melting nozzle tube, a slag pool, a molten pool, a weld seam, a weld initiation groove, a second conductive path, and the negative terminal of the power supply; the second circuit includes, in sequence, the positive terminal of the power supply, a first conductive path, a melting nozzle tube, a slag pool, a molten pool, a liquid-cooled forming slider, a third conductive path, and the negative terminal of the power supply.

[0021] Adjust the adjustable resistance of the liquid-cooled forming slider to adjust the ratio of current and power in the first circuit and the second circuit to follow the corresponding preset ratio value until welding is completed.

[0022] Compared with the prior art, the electroslag welding device and welding method provided by the present invention, by adding a new current loop (a second loop, which sequentially includes the positive terminal of the power supply, a first conductive path, a melting nozzle tube, a slag pool, a molten pool, a liquid-cooled forming slider, a third conductive path, and the negative terminal of the power supply), can optimize the temperature distribution of heat in the molten pool and slag pool by adjusting the ratio of the current and power of the first loop and the second loop during the actual welding process. This achieves a uniform distribution of heat and temperature and effectively improves the forming quality of the electroslag weld.

[0023] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below and particularly pointed out in the claims. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to include all such aspects and their equivalents. Attached Figure Description

[0024] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings and the contents of the claims, and with a more complete understanding of the invention. In the drawings:

[0025] Figure 1 This is a structural schematic diagram of the electroslag welding device provided in an embodiment of the present invention;

[0026] In the figure, 1 is the welding wire, 2 is the welding nozzle tube, 3 is the workpiece body, 4 is the liquid outlet, 5 is the slag pool, 6 is the molten pool, 7 is the weld seam, 8 is the weld initiation groove, 9 is the second conductive path, 10 is the third conductive path, 11 is the power supply, 12 is the first conductive path, 13 is the liquid-cooled forming slider, and 14 is the liquid inlet.

[0027] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0028] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Figure 1 The structural principle of the electroslag welding apparatus provided in the embodiments of the present invention is shown, which consists of... Figure 1 It is understood that the electroslag welding apparatus provided by the present invention includes a workpiece body 3 as the main body of the electroslag welding apparatus and a power supply 11 for supplying power to the entire electroslag welding apparatus.

[0031] Specifically, a slag pool 5 is provided inside the main body 3 of the workpiece, and the slag pool 5 contains metal slag. A molten pool 6 (metal molten pool 6) is provided below the slag pool 5. After passing through the molten pool 6, the metal slag in the slag pool 5 accumulates below the molten pool 6 to form a solid weld 7. Furthermore, a liquid-cooled forming slider 13 is provided around the molten pool 6. The liquid-cooled forming slider 13 cools and forms the molten metal slag flowing out of the molten pool 6 and ensures that the welding torch guide does not overheat, so that the molten metal slag forms a solid weld 7. It should be noted that the height of the slag pool 5 and the molten pool 6 (the slag pool 5 and the molten pool 6 move synchronously) increases with the accumulation of the solid weld 7, and the height of the liquid-cooled forming slider 13 increases with the molten pool 6 (the liquid-cooled forming slider 13 moves upward under the action of the slag pool 5 and the molten pool 6).

[0032] To improve the forming quality of the electroslag weld 7, a first conductive path 12 is provided between the slag pool 5 and the positive electrode of the power supply 11, a second conductive path 9 is provided between the weld 7 and the negative electrode of the power supply 11 (this path corresponds to part of the circuit structure in the existing scheme), and a third conductive path 10 is provided between the liquid-cooled forming slider 13 and the negative electrode (this path corresponds to part of the structure of the newly added second circuit provided by the present invention).

[0033] The electroslag welding apparatus provided by the present invention, by adding a new current loop (second loop), can optimize the temperature distribution of heat in the molten pool 6 and slag pool 5 by adjusting the ratio of current and power of the first loop and the second loop during the actual welding process, so that the ratio of current and power of the first loop and the second loop both follow the corresponding preset ratio value, thereby achieving uniform distribution of heat and temperature and effectively improving the forming quality of electroslag weld 7.

[0034] In addition, to enable switching control of each path, a first switch (not shown in the figure) is provided on the first conductive path 12, a second switch (not shown in the figure) is provided on the second conductive path 9, and a third switch (not shown in the figure) is provided on the third conductive path 10; and, to facilitate observation of the current flowing through each path, a first ammeter (not shown in the figure) is provided on the first conductive path 12, a second ammeter (not shown in the figure) is provided on the second conductive path 9, and a third ammeter (not shown in the figure) is provided on the third conductive path 10.

[0035] In a specific embodiment of the present invention, in order to cool and shape molten metal slag using a liquid-cooled forming slider 13, a circulating coolant is installed inside the liquid-cooled forming slider 13; and an inlet 14 and an outlet 4 are provided on the liquid-cooled forming slider 13. The liquid-cooled forming slider 13 is connected to an external liquid supply device through the inlet 14 and the outlet 4, and the circulating coolant inside the liquid-cooled forming slider 13 is circulated and cooled by the liquid supply device in conjunction with the inlet 14 and the outlet 4.

[0036] Furthermore, in order to adjust the ratio of current and power between the first circuit and the second circuit, an adjustable resistor is provided in the liquid-cooled forming slider 13, which is connected between the molten pool 6 and the third conductive path 10. By adjusting the input resistance of the adjustable resistor, the ratio of current and power between the first circuit and the second circuit can be adjusted.

[0037] In a preferred embodiment of the present invention, the adjustable resistor can be formed by the circulating coolant; by adjusting the volume and flow rate of the circulating coolant through the liquid supply device in conjunction with the liquid inlet 14 and the liquid outlet 4, the resistance of the adjustable resistor in the liquid-cooled forming slider 13 can be adjusted.

[0038] In addition, to achieve the energization and arc initiation of slag formation in the electroslag welding device provided by the present invention, a welding nozzle tube 2 (i.e., an externally coated welding electrode) can be installed in the unobstructed slag hole in the middle of the slag pool 5. The slag pool 5 is connected to the first conductive passage 12 through the welding nozzle tube 2. Furthermore, a welding wire 1 is installed in the welding nozzle tube 2, which passes through the externally coated welding electrode, as a melting electrode. The welding wire 1, together with the externally coated welding electrode, achieves the energization and arc initiation of slag formation in the electroslag welding device provided by the present invention.

[0039] In addition, to facilitate the collection of weld seam 7 by the workpiece body 3, a weld initiation groove 8 can be provided at the bottom of the workpiece body 3. The weld seam 7 accumulates and forms within the weld initiation groove 8, and continues to rise until it enters the interior of the workpiece body 3 (e.g., Figure 1 (As shown).

[0040] On the other hand, to facilitate understanding of the working principle of the electroslag welding apparatus provided by the present invention, the present invention also provides a welding method for the electroslag welding apparatus, the welding method comprising:

[0041] When the power supply 11 is turned on and the first and second switches are closed, the weld 7 begins to form in the weld slag formation groove 8 after the arc is started and slag is formed. The molten pool 6 begins to rise as the weld 7 accumulates, and the liquid-cooled forming slider 13 begins to move upward with the molten pool 6.

[0042] Close the third switch to form a first circuit and a second circuit; wherein, the first circuit includes, in sequence, the positive terminal of the power supply 11, the first conductive path 12, the melting nozzle tube 2, the slag pool 5, the molten pool 6, the weld seam 7, the weld initiation groove 8, the second conductive path 9, and the negative terminal of the power supply 11; the second circuit includes, in sequence, the positive terminal of the power supply 11, the first conductive path 12, the melting nozzle tube 2, the slag pool 5, the molten pool 6, the liquid-cooled forming slider 13, the third conductive path 9, and the negative terminal of the power supply 11;

[0043] Adjust the adjustable resistance of the liquid-cooled forming slider 13 to adjust the ratio of current and power in the first circuit and the second circuit to follow the corresponding preset ratio value until the welding is completed.

[0044] It should be noted that for the first circuit, as the height of weld 7 increases, the resistance connected to the first circuit will continuously increase (the resistance connected to the first circuit includes the resistance of weld 7, the resistance of weld groove 8, the resistance of molten pool 6, the resistance of slag pool 5, etc., of which only the resistance of weld 7 will continuously increase), causing the current and power of the first circuit to continuously change; for the second circuit, by adjusting the resistance of the adjustable resistor, the resistance connected to the second circuit (the resistance connected to the second circuit includes the resistance of molten pool 6, the resistance of slag pool 5, the adjustable resistance of liquid-cooled forming slider 13, etc., of which only the resistance of the adjustable resistor of liquid-cooled forming slider 13 is adjustable) is adjusted, thereby adjusting the current of the second circuit, and thus balancing the current and power of the first circuit and the second circuit, so that the ratio of the current and power of the first circuit and the second circuit both follow the corresponding preset ratio value.

[0045] Furthermore, it should be noted that the specific setting of the aforementioned preset ratio (which can be a dynamic value), and how to adjust the adjustable resistance of the liquid-cooled forming slider 13 to ensure that the current and power ratios of the first circuit and the second circuit follow the corresponding preset ratios, are all related to the parameters of each component of the device in the actual production process. After the parameters of each component of the device are determined, the specific setting of the preset ratio (which can be a dynamic value) and the specific adjustment method of adjusting the adjustable resistance of the liquid-cooled forming slider 13 to ensure that the current and power ratios of the first circuit and the second circuit follow the corresponding preset ratios can be determined through a large number of experiments. The innovation of this invention lies in the fact that by setting the second circuit and the adjustable resistance, the forming quality of the electroslag weld 7 can be improved. Therefore, the detailed process of setting the aforementioned preset ratio (which can be a dynamic value) and how to adjust the adjustable resistance of the liquid-cooled forming slider 13 to ensure that the current and power ratios of the first circuit and the second circuit follow the corresponding preset ratios will not be elaborated here.

[0046] As per the above reference Figure 1 The electroslag welding apparatus and welding method according to the present invention have been described by way of example. However, those skilled in the art should understand that various modifications can be made to the electroslag welding apparatus and welding method proposed in the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. An electroslag welding apparatus, characterized in that, The system includes a workpiece body and a power supply. A slag pool is provided within the workpiece body, and a molten pool is located below the slag pool. Metal slag from the slag pool accumulates below the molten pool to form a weld. A liquid-cooled forming slider is located around the periphery of the molten pool. The height of the molten pool increases with the accumulation of the weld, and the height of the liquid-cooled forming slider also increases with the molten pool. A first conductive path is provided between the slag pool and the positive terminal of the power supply, a second conductive path is provided between the weld and the negative terminal of the power supply, and a third conductive path is provided between the liquid-cooled forming slider and the negative terminal; wherein, the first circuit includes the first conductive path and the second conductive path, and the second circuit includes the first conductive path and the third conductive path.

2. The electroslag welding apparatus as described in claim 1, characterized in that, A first switch is provided on the first conductive path, a second switch is provided on the second conductive path, and a third switch is provided on the third conductive path.

3. The electroslag welding apparatus as described in claim 2, characterized in that, A first ammeter is provided in the first conductive path, a second ammeter is provided in the second conductive path, and a third ammeter is provided in the third conductive path.

4. The electroslag welding apparatus as described in claim 3, characterized in that, The liquid-cooled forming slider is equipped with circulating coolant; and... The liquid-cooled molding slider is provided with a liquid inlet and a liquid outlet, and the liquid-cooled molding slider is connected to an external liquid supply device through the liquid inlet and the liquid outlet.

5. The electroslag welding apparatus as described in claim 4, characterized in that, An adjustable resistor is provided inside the liquid-cooled forming slider, which is connected between the molten pool and the third conductive path.

6. The electroslag welding apparatus as described in claim 5, characterized in that, The circulating coolant forms the adjustable resistor; and... The volume and flow rate of the circulating coolant are adjusted by means of the liquid supply device in conjunction with the liquid inlet and the liquid outlet, thereby adjusting the resistance value of the adjustable resistor.

7. The electroslag welding apparatus as described in claim 1, characterized in that, A melting nozzle tube is installed inside the slag hole of the slag pool, and the slag pool is connected to the first conductive path through the melting nozzle tube.

8. The electroslag welding apparatus as described in claim 7, characterized in that, Welding wire is installed inside the fusion nozzle tube.

9. The electroslag welding apparatus as described in claim 1, characterized in that, A weld initiation groove is provided at the bottom of the workpiece body, and the weld seam is formed by accumulation within the weld initiation groove.

10. A welding method using the electroslag welding apparatus according to any one of claims 1 to 9, characterized in that, The welding method includes: Turn on the power supply, close the first switch and the second switch, and after the power is applied to start the arc and slag formation, the weld begins to form in the weld initiation groove. The molten pool begins to rise as the weld accumulates, and the liquid-cooled forming slider begins to move upward with the molten pool. Close the third switch to form a first circuit and a second circuit; wherein, the first circuit includes, in sequence, the positive terminal of the power supply, a first conductive path, a melting nozzle tube, a slag pool, a molten pool, a weld seam, a weld initiation groove, a second conductive path, and the negative terminal of the power supply; the second circuit includes, in sequence, the positive terminal of the power supply, a first conductive path, a melting nozzle tube, a slag pool, a molten pool, a liquid-cooled forming slider, a third conductive path, and the negative terminal of the power supply. Adjust the adjustable resistance of the liquid-cooled forming slider to adjust the ratio of current, voltage and power of the first circuit and the second circuit to follow the corresponding preset ratio value until the welding is completed.

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