Electric-shaft remelting device and process capable of splicing multi-power coordinated control

Abstract

The present application relates to the technical fields of electroslag remelting, and particularly relates to a multi-power coordinated control splicing electroslag remelting device and process, which comprises a composite electrode, a remelting furnace and a molten pool monitoring system, the composite electrode is arranged in the crystallizer of the remelting furnace, the molten pool monitoring system is arranged in the remelting furnace, the bottom of the composite electrode is provided with a bottom box and an insulating rubber plate, the composite electrode is spliced by a lifting consumable electrode and multiple transverse consumable electrodes, the multiple transverse consumable electrodes are arranged in an array under the lifting consumable electrode, the lifting consumable electrode and each transverse consumable electrode are provided with an independent inverter power supply, and the independent inverter power supply and the molten pool monitoring system are controlled through a PID closed loop, the present application has the beneficial effects of reducing the preparation difficulty and cost of large electrodes, supporting flexible combination and replacement, independently adjusting the melting speed of each electrode, refining the grain and reducing defects.

Description

Technical Field

[0001] This invention relates to the field of electroslag remelting technology, and in particular to an electroslag remelting device and process that can be spliced ​​with multiple power sources for coordinated control. Background Technology

[0002] Traditional electroslag remelting processes typically employ a single large electrode, whose fabrication requires complex forging or casting processes, resulting in high costs and a high scrap rate. For example, electrodes with a diameter exceeding 500 mm require precise control of compositional uniformity; any localized defects can lead to melting failure. Furthermore, the melting rate of a single electrode is limited by the concentrated distribution of power, easily leading to uneven heat distribution in the molten pool, causing compositional segregation such as nitrogen escape rates exceeding 15% and solidification defects such as columnar crystals accounting for over 70%.

[0003] Chinese patent CN112359216A, entitled "A Multi-Electrode Electroslag Remelting Device and Electroslag Remelting Process for High-Nitrogen Austenitic Stainless Steel," discloses a method that improves the uniformity of the molten pool composition by simultaneously melting multiple electrodes and uses nitrogen protection to reduce nitrogen escape. However, this technology does not involve electrode splicing design and still relies on traditional large integral electrodes, resulting in high manufacturing costs and insufficient flexibility. In addition, the lack of independent power supply control between electrodes leads to low precision in melting rate adjustment, and the absence of an external heating mechanism during solidification results in uneven thermal field distribution in the molten pool, which easily produces columnar crystals and shrinkage cavities.

[0004] Chinese patent CN109158718B, entitled "Method for preparing an electrode head, tool electrode, and method for preparing a tool electrode," proposes a modular electrode head preparation method that reduces electrode costs by simplifying the processing flow. However, its modular design only addresses the local structure of the electrode head and does not extend to the overall electrode system. Furthermore, it uses a single power supply, making it impossible to achieve coordinated control of the melting rate of multiple electrodes, and the risk of component segregation still exists during the melting process. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides an electroslag remelting device and process with multi-power source coordinated control. Through modular electrode design and multi-power source coordinated control, the difficulty and cost of large electrode preparation are reduced, and flexible combination and replacement are supported. The melting rate of each electrode can be independently adjusted to optimize the thermal field distribution of the molten pool. Through continuous heating by transverse consumable electrodes, the grains are refined and defects are reduced.

[0006] To achieve the above objectives, the present invention employs the following technical solution: An electroslag remelting device with multi-power source coordinated control includes a composite electrode, a remelting furnace, and a molten pool monitoring system. The composite electrode is installed inside the crystallizer of the remelting furnace, with a bottom box and insulating rubber plate at its bottom. The molten pool monitoring system is installed inside the remelting furnace. The composite electrode is composed of a rising consumable electrode and multiple transverse consumable electrodes. An array of multiple transverse consumable electrodes is arranged below the rising consumable electrode. The rising consumable electrode is connected to a rising electrode clamp via a rising dummy electrode. The rising electrode clamp is located above the remelting furnace. Each transverse consumable electrode is connected to a transverse reciprocating electrode clamp via a transverse dummy electrode. The transverse reciprocating electrode clamp is located outside the remelting furnace. Each rising consumable electrode and each transverse consumable electrode is equipped with an independent inverter power supply. The independent inverter power supply and the molten pool monitoring system are controlled by a PID closed-loop system.

[0007] Furthermore, the multiple transverse consumable electrodes are spliced ​​together using a mortise and tenon structure according to the shape of the crystallizer, with an axial deviation of ≤0.2mm and a splicing gap of ≤0.5mm.

[0008] Furthermore, the dimensions of the lateral consumable electrode are Φ = 50~150mm.

[0009] Furthermore, the lifting electrode clamp is equipped with a servo motor with a motor accuracy of ±0.1mm.

[0010] Furthermore, the lateral reciprocating electrode chuck moves radially by ±50mm.

[0011] Furthermore, the independent inverter power supply has an output power P of 50 to 500 kW, power fluctuation is controlled within ±5%, and power response time is ≤50 ms.

[0012] Furthermore, the electroslag remelting process specifically includes the following: S1. Electrode prefabrication and splicing: Multiple transverse consumable electrodes and rising consumable electrodes are spliced ​​together to form a composite electrode. The transverse consumable electrodes have the same length but adjustable diameter. The composite electrode is equipped with an insulating ceramic gasket. S2, Power Parameter Settings: Based on the target melting rate and the thermal field requirements of the molten pool, the power of each electrode is allocated by the central controller controlled by PID closed loop. The power of the transverse consumable electrode is 10% to 20% higher than that of the rising and falling consumable electrodes, forming a gradient thermal field. S3, Dynamic melting rate control in smelting: The electroslag remelting furnace is started, and smelting is carried out under normal or high pressure. The rising and lowering consumable electrodes and each transverse consumable electrode are melted independently and dripped into the molten pool. The melting rate is monitored in real time and the power supply is dynamically adjusted. The central controller allocates the power of each electrode according to the molten pool monitoring data through a fuzzy PID algorithm. The melting rate fluctuation is ≤±3%. S4. Solidification auxiliary heating: During the solidification stage of electroslag ingots, the transverse consumable electrode heating mode is activated, with a heating temperature ≥1600℃, lasting for 30–60 min. S5, Intelligent Capping and Ingot Discharge: When the composite electrode has 5% remaining, stop melting and start pulsed power output with an output frequency of 1-2Hz. After the spindle is removed from the mold, ultrasonic testing is performed, and the defect rate is ≤0.5%.

[0013] Furthermore, the temperature uniformity within the molten pool in S3 is controlled within ±15%.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1) Modular design: Reduces the difficulty of fabricating large electrodes, shortens the production cycle, reduces material waste, and lowers the manufacturing cost: Modular electrode production saves 20% to 30% of materials and shortens the processing cycle by 40%; 2) Precise control of melting rate: Through multi-power source coordinated adjustment, the uniformity of the molten pool composition is ensured, with a segregation index (SI) ≤ 1.5; 3) Solidification structure optimization: peripheral electrode-assisted heating refines grains, with equiaxed crystal ratio ≥90% and shrinkage rate ≤1% in electroslag ingots; 4) Cost-effectiveness: Electrode fabrication costs are reduced by 40%, and the multi-power source time-sharing power supply strategy reduces total energy consumption by 18%. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the composite electrode structure described in this invention.

[0016] In the diagram: 1. Lifting electrode clamp; 2. Lifting dummy electrode; 3. Lifting consumable electrode; 4. Lateral reciprocating electrode clamp; 5. Lateral dummy electrode; 6. Lateral consumable electrode; 7. Bottom water tank and insulating rubber plate. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figure 1 As shown, an electroslag remelting device with multi-power coordinated control includes a composite electrode, a remelting furnace, and a molten pool monitoring system. The composite electrode is set inside the crystallizer of the remelting furnace. A bottom box and an insulating rubber plate 7 are set at the bottom of the composite electrode for cooling and insulation. The molten pool monitoring system is set inside the remelting furnace. The molten pool monitoring system integrates an infrared thermal imager and a spectrometer to provide real-time feedback of molten pool temperature and composition data to the central controller. The composite electrode is composed of a rising consumable electrode 3 and multiple transverse consumable electrodes 6 spliced ​​together. The composite electrode is assembled into a cube or cylinder according to the shape of the crystallizer. Multiple transverse consumable electrodes 6 are arrayed below the rising consumable electrode 3 to form a composite electrode. The rising consumable electrode 3 is connected to a rising electrode chuck 1 through a rising dummy electrode 2. The rising electrode chuck 1 is set above the remelting furnace and is equipped with a servo motor with a motor accuracy of ±0.1mm. The servo motor controls the rising and falling of the rising electrode chuck 1. During the melting process, as the composite electrode melts, the rising electrode chuck 1 drives the composite electrode to descend. Each transverse consumable electrode 6 is connected to a transverse reciprocating electrode chuck 4 through a transverse dummy electrode 5. The transverse reciprocating electrode chuck 4 is set outside the remelting furnace. The transverse reciprocating electrode chuck 4 cooperates with the rising electrode chuck 1 to splice the transverse consumable electrode 6 and the rising consumable electrode 3 into a composite electrode and installs an insulating ceramic gasket. Each of the rising and lowering self-consuming electrodes 3 and each of the transverse self-consuming electrodes 6 is equipped with an independent inverter power supply. The independent inverter power supply and the molten pool monitoring system are controlled by PID closed loop. The molten pool detection system monitors the melting rate in real time and dynamically adjusts the power of each independent inverter power supply.

[0018] Furthermore, the multiple transverse consumable electrodes 6 are assembled by mortise and tenon joints according to the shape of the crystallizer, with an axial deviation of ≤0.2mm and an assembly gap of ≤0.5mm.

[0019] Furthermore, the lateral consumable electrode 6 is a prefabricated standardized small electrode with a size Φ=50~150mm and a composition error ≤1%.

[0020] Furthermore, the transverse reciprocating electrode chuck 4 moves radially by ±50mm.

[0021] Furthermore, the independent inverter power supply has an output power P of 50 to 500 kW, power fluctuation is controlled within ±5%, and power response time is ≤50 ms.

[0022] Furthermore, the electroslag remelting process specifically includes the following: S1. Electrode prefabrication and splicing: Multiple transverse consumable electrodes 6 and rising consumable electrodes 3 are spliced ​​together to form a composite electrode. The transverse consumable electrodes 6 have the same length but adjustable diameter. The composite electrode is equipped with an insulating ceramic gasket. S2, Power Parameter Settings: Based on the target melting rate and the thermal field requirements of the molten pool, the power of each electrode is allocated by the central controller through PID closed-loop control. The power of the transverse consumable electrode 6 is 10% to 20% higher than that of the rising and falling consumable electrode 3, forming a gradient thermal field. S3, Dynamic melting rate control in smelting: Start the electroslag remelting furnace and carry out smelting under normal or high pressure. The rising and lowering self-consumable electrodes 3 and each transverse self-consumable electrode 6 are melted independently and dripped into the molten pool. The molten pool detection system monitors the melting rate in real time and dynamically adjusts the power of each independent inverter power supply. The central controller allocates the power of each electrode according to the molten pool monitoring data through a fuzzy PID algorithm. The melting rate fluctuation is ≤±3%, and the molten pool temperature uniformity is controlled within ±15℃. S4. Solidification auxiliary heating: During the solidification stage of the electroslag ingot, the horizontal consumable electrode 6 heating mode is activated, with a heating temperature ≥1600℃ and a duration of 30-60 minutes. S5, Intelligent Capping and Ingot Discharge: When the composite electrode has 5% remaining, stop melting and start pulsed power output with an output frequency of 1-2Hz. After the spindle is removed from the mold, ultrasonic testing is performed, and the defect rate is ≤0.5%.

[0023] like Figure 1 As shown in Table 1, the composite electrode specifications of this invention are shown in Table 2; the percentage of smelting slag composition of this invention is shown in Table 2; the power supply process parameters of this invention are shown in Table 3; the electroslag remelting process parameters of this invention are shown in Table 4; and the electroslag ingot effect of this invention is shown in Table 5.

[0024] A horizontal consumable electrode array is arranged at the bottom of the rising and falling consumable electrodes to form a composite electrode.

[0025] Table 1 - Specifications of composite electrodes in embodiments of the present invention: Table 2 - Percentage of smelting slag composition (%) in embodiments of the present invention: Table 3 - Power supply process parameters of embodiments of the present invention: Table 4 - Electroslag remelting process parameters of the present invention: Table 5 - Effects of electroslag ingots in the embodiments of the present invention: The examples show that by coordinating the adjustment of multiple power sources, the uniformity of the molten pool composition is ensured, with a segregation index (SI) ≤ 1.5; the external electrode-assisted heating refines the grains, resulting in an equiaxed crystal ratio of ≥ 90% and a shrinkage rate of ≤ 1% in the electroslag ingot.

[0026] 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 concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-power source coordinated control electroslag remelting device, comprising a composite electrode, a remelting furnace, and a molten pool monitoring system, wherein the composite electrode is disposed within the crystallizer of the remelting furnace, and a bottom box and an insulating rubber plate are disposed at the bottom of the composite electrode; the molten pool monitoring system is disposed within the remelting furnace, characterized in that... The composite electrode is composed of a rising consumable electrode and multiple transverse consumable electrodes. The array of multiple transverse consumable electrodes is arranged below the rising consumable electrode. The rising consumable electrode is connected to a rising electrode clamping plate via a rising dummy electrode. The rising electrode clamping plate is arranged above the remelting furnace. Each transverse consumable electrode is connected to a transverse reciprocating electrode clamping plate via a transverse dummy electrode. The transverse reciprocating electrode clamping plate is arranged outside the remelting furnace. Each rising consumable electrode and each transverse consumable electrode is equipped with an independent inverter power supply. The independent inverter power supply and the molten pool monitoring system are controlled by PID closed-loop control.

2. The electroslag remelting device with multi-power source coordinated control according to claim 1, characterized in that, The multiple transverse consumable electrodes are spliced ​​together using a tenon and mortise structure according to the shape of the crystallizer, with an axial deviation of ≤0.2mm and a splicing gap of ≤0.5mm.

3. The electroslag remelting device with multi-power source coordinated control according to claim 1, characterized in that, The dimensions of the lateral consumable electrode are Φ = 50~150mm.

4. The electroslag remelting device with multi-power source coordinated control according to claim 1, characterized in that, The lifting electrode clamp is equipped with a servo motor with a motor accuracy of ±0.1mm.

5. The electroslag remelting device with multi-power source coordinated control according to claim 1, characterized in that, The radial movement of the transverse reciprocating electrode chuck is ±50mm.

6. The electroslag remelting device with multi-power source coordinated control according to claim 1, characterized in that, The independent inverter power supply has an output power of P = 50~500kW, power fluctuation is controlled within ±5%, and power response time is ≤50ms.

7. An electroslag remelting process for an electroslag remelting device with multi-power source coordinated control according to any one of claims 1 to 6, characterized in that, Specifically, it includes the following: S1. Electrode prefabrication and splicing: Multiple transverse consumable electrodes and rising consumable electrodes are spliced ​​together to form a composite electrode. The transverse consumable electrodes have the same length but adjustable diameter. The composite electrode is equipped with an insulating ceramic gasket. S2, Power Parameter Settings: Based on the target melting rate and the thermal field requirements of the molten pool, the power of each electrode is allocated by the central controller controlled by PID closed loop. The power of the transverse consumable electrode is 10% to 20% higher than that of the rising and falling consumable electrodes, forming a gradient thermal field. S3, Dynamic melting rate control in smelting: The electroslag remelting furnace is started, and smelting is carried out under normal or high pressure. The rising and lowering consumable electrodes and each transverse consumable electrode are melted independently and dripped into the molten pool. The melting rate is monitored in real time and the power supply is dynamically adjusted. The central controller allocates the power of each electrode according to the molten pool monitoring data through a fuzzy PID algorithm. The melting rate fluctuation is ≤±3%. S4. Solidification auxiliary heating: During the solidification stage of electroslag ingots, the transverse consumable electrode heating mode is activated, with a heating temperature ≥1600℃, lasting for 30–60 min. S5, Intelligent Capping and Ingot Discharge: When the composite electrode has 5% remaining, stop melting and start pulsed power output with an output frequency of 1-2Hz. After the spindle is removed from the mold, ultrasonic testing is performed, and the defect rate is ≤0.5%.

8. The electroslag remelting process of the electroslag remelting device with multi-power source coordinated control as described in claim 7, characterized in that, The temperature uniformity within the molten pool in S3 is controlled within ±15%.

Images