Vacuum lock and short-process high-temperature alloy welding wire manufacturing system

Abstract

The utility model discloses a vacuum lock and a short-process high-temperature alloy welding wire manufacturing system, and relates to the field of high-temperature alloy welding wire manufacturing. And the vacuum lock is used for dynamic sealing when the dummy bar and the casting blank penetrate through an inner hole of the vacuum lock. The utility model discloses a short-process high-temperature alloy welding wire manufacturing system based on a vacuum lock. The device comprises a vacuum chamber, a vacuum lock, a medium-frequency smelting furnace, a crystallizer, a throwing machine, a bottom blowing device and an inner hole gas injection device, the vacuum chamber comprises a chamber body with an open upper end and an upper cover hermetically mounted at the open upper end of the chamber body; the bottom blowing device is installed on an installation opening of the medium-frequency smelting furnace and used for blowing inert gas into an inner cavity of the medium-frequency smelting furnace. The inner hole gas injection device is connected to a gas injection opening of the vacuum lock and used for injecting inert gas into an inner hole of the vacuum lock. The device is matched with the process of'intermediate-frequency smelting in a vacuum environment + inert gas protection horizontal continuous casting ', is used for manufacturing the high-temperature alloy welding wires, and realizes short-process, continuous and low-cost production of the high-temperature alloy welding wires.

Description

Technical Field

[0001] This utility model relates to the field of high-temperature alloy welding wire manufacturing, and in particular to a vacuum lock and short-process high-temperature alloy welding wire manufacturing system. Background Technology

[0002] High-temperature alloy welding wire is widely used in many fields due to its high temperature resistance, corrosion resistance, and high strength. For example: Ⅰ. In the aerospace field, it is used for the connection and repair of critical components such as engine parts, turbine blades, and combustion chambers, meeting the operational requirements of aircraft in extreme environments; Ⅱ. In the petrochemical field, it is used for the connection and repair of equipment such as pipelines, valves, and reactors, capable of withstanding high temperatures, high pressures, and corrosive media; Ⅲ. In the power industry, it is used for the connection and repair of critical components of equipment such as gas turbines, steam turbines, and generators, ensuring the stable operation of power equipment.

[0003] like Figure 4 As shown, the current production process of high-temperature alloy welding wire mainly includes the following key steps:

[0004] S01, Vacuum Induction Melting: Raw materials are introduced into a vacuum induction melting furnace, and a vacuum is drawn for melting. Due to the reduced pressure, the solubility of oxygen in the molten steel decreases, causing it to precipitate and thus achieving deoxidation. The molten steel is then discharged into a mold, and after the molten steel has completely solidified, a primary melting ingot is obtained. Since the primary melting ingot has inherent defects such as surface roughness (pits), shrinkage cavities, segregation, and slag entrapment, it is necessary to eliminate them through a subsequent electroslag remelting process.

[0005] S02, Electroslag Secondary Remelting: An electroslag remelting furnace (the structure of a typical electroslag remelting furnace can be referenced in CN207016840U: Single-column double-conductive horizontal arm ingot-pulling electroslag remelting furnace device) is used to remelt the primary smelting ingot to produce secondary remelted ingots. The secondary remelted ingot basically eliminates some inherent defects of the primary smelting ingot. The remaining small number of defects need to be eliminated through subsequent forging processes.

[0006] Introduction to the equipment structure of electroslag secondary remelting: The single-column double-conductive horizontal arm ingot-pulling electroslag remelting furnace device includes a worktable mounted on a base plate, an upper column located at the upper end of the worktable, a lower column located at the lower end of the worktable, and a crystallizer located on the side of the worktable; the upper column is equipped with a first electrode clamping arm and a second electrode clamping arm; both the first electrode clamping arm and the second electrode clamping arm move up and down along the upper column; the ingot-pulling column is equipped with a first slag ingot clamping arm and a second slag ingot clamping arm, both of which move up and down along the ingot-pulling column.

[0007] The operation process of electroslag secondary remelting is as follows: The arc igniter is placed on the ingot ignition rod inserted from the bottom of the crystallizer, and the high voltage is turned on to ignite the arc; the first electrode clamping arm and the second electrode clamping arm are alternately energized to clamp the self-dissolving electrode (primary melting ingot) and move it downward continuously. At the same time, the first slag ingot clamping arm and the second slag ingot clamping arm are alternately energized to clamp the electroslag ingot (secondary remelting ingot) and move it downward, and it is discharged through the groove on the bottom plate.

[0008] The working principle of electroslag remelting (ESR) secondary remelting is as follows: During equipment operation, operators prepare for remelting according to the process specifications. After ignition of the slag, the consumable electrode (for primary melting and casting), slag pool, molten metal pool, ESR ingot, and ingot guide arm form a circuit through short-circuit wires and a transformer. During energization, the slag pool releases Joule heat, gradually melting the tip of the consumable electrode. The molten metal gathers into droplets, passes through the slag pool, and falls into the crystallization pool, forming a molten metal pool. Under water cooling, it rapidly solidifies to form an ESR ingot (secondary remelting ingot).

[0009] S03, Forging: Forging the remelted ingot under specific temperature conditions to form a square billet of a specific size; this process includes steps such as annealing and grinding. This process is used to eliminate inherent defects such as porosity and segregation in the remelted ingot, and also improves the density of the microstructure, refines the grains, and provides a good foundation for subsequent hot rolling.

[0010] S04, Post-processing: The billet is processed by hot rolling to prepare wire rods that meet the requirements of subsequent drawing. The wire rods are then subjected to solution treatment, pickling, rough drawing and fine drawing processes in sequence to gradually reduce the diameter of the welding wire to meet the process requirements, thus obtaining the finished high-temperature alloy welding wire.

[0011] Therefore, it can be seen that the current production process of high-temperature alloy welding wire has the following shortcomings:

[0012] 1. Long process flow; the core process before post-processing includes two melting processes and one forging and shaping process, and the two melting processes are completed in different equipment, making the process flow lengthy.

[0013] 2. High production costs: The core processes before post-processing include two melting processes and one forging and shaping process. Each process generates waste, losses and labor costs during the process, ultimately leading to high production costs.

[0014] 3. Poor continuity: The core processes before post-processing include two melting processes and one forging and shaping process. The ingot cannot be seamlessly connected between any two adjacent processes and requires manual transfer.

[0015] 4. High requirements for raw materials: The above process is difficult to remove sulfur from the raw materials. The sulfur in the raw materials will be carried into the final product through each process. Therefore, it is necessary to control it at the source and purchase raw materials with sulfur content that meets the requirements of the finished product.

[0016] In conclusion, simplifying the process, reducing production costs, and lowering raw material requirements, while ensuring the quality of high-temperature alloy welding wire products, have always been key areas of focus for relevant enterprises. Utility Model Content

[0017] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a vacuum lock and short-process high-temperature alloy welding wire manufacturing system. It is used for the manufacture of high-temperature alloy welding wire and solves the problems of long production processes, high production costs, poor continuity, and high raw material requirements in existing high-temperature alloy welding wire production processes.

[0018] The technical solution of this utility model is: a vacuum lock, used for dynamic sealing when the ingot rod and the billet pass through its inner hole; it has an inner hole for the billet and the ingot rod to pass through for sealing, and an air injection hole and an air exhaust hole connected to the inner hole are provided on its exterior.

[0019] A further technical solution of this utility model is: a vacuum lock, comprising a first sleeve, expansion rings, sealing rings, and a clamping assembly; the first sleeve is a sleeve shape with openings at both ends, its inner hole including a middle section and end sections on both sides of the middle section, with annular stepped surfaces between the middle section and the two end sections respectively, the diameter of the middle section being smaller than that of the two end sections, the outer surface of the first sleeve having an air injection hole and an exhaust hole connected to the middle section, and flanges A welded to both ends of the first sleeve, with a plurality of threaded holes evenly distributed in annular pattern on flanges A; at least three expansion rings are stacked face-to-face to form a group, and two groups of expansion rings are respectively installed in the two end sections of the first sleeve, the inner holes of all expansion rings in each group being sequentially connected to form a casting sealing section; two sealing rings are respectively installed in the two end sections of the first sleeve, and the end face of the sealing ring is connected to the end hole. The outermost expansion ring of the first sleeve contacts the sealing ring. Two sets of clamping assemblies are installed in the end holes at both ends of the first sleeve. They are used to press the sealing ring and a set of expansion rings in the end holes onto the annular step surface. The clamping assembly includes a second sleeve, screws, and nuts. The front end of the second sleeve is inserted into the end hole of the first sleeve, and its front end face contacts the end face of the sealing ring. A flange B is welded to the rear end face of the second sleeve. The flange B has through holes that correspond to the positions of the threaded holes on the flange A and have the same number. The number of screws and nuts is the same as the number of through holes on the flange B. All screws pass through the through holes on the second sleeve and are screwed into the corresponding threaded holes on the first sleeve. Multiple nuts are threaded onto each screw and abut against the flange B. By adjusting the nuts, the front end of the second sleeve presses the sealing ring and a set of expansion rings in the end holes onto the annular step surface.

[0020] The technical solution of this utility model is: a short-process high-temperature alloy welding wire manufacturing system, based on the above-mentioned vacuum lock; it includes a vacuum chamber, a vacuum lock, a medium-frequency melting furnace, a crystallizer, a billet pulling machine, a bottom blowing device, and an inner hole gas injection device;

[0021] The vacuum chamber includes a chamber body with an open top and a top cover that is sealed and installed at the open top of the chamber body. The chamber body has an inner cavity for accommodating the medium-frequency melting furnace and the crystallizer. The chamber body has a negative pressure exhaust port that connects to the inner cavity. The top cover has an operating port for adding materials and taking temperature samples. The operating port has a balance valve inside.

[0022] The vacuum lock is fixedly installed on the side wall of the vacuum chamber. It has an inner hole through which the casting billet and the ingot rod pass. The two ends of the inner hole are respectively connected to the inner cavity of the vacuum chamber and the outside of the vacuum chamber. The outside of the lock has an injection hole connected to the inner hole and an exhaust hole connected to the inner hole.

[0023] The medium-frequency melting furnace is located inside the vacuum chamber. The upper end of the medium-frequency melting furnace is open, the lower end is a water inlet, and the bottom is an installation port. The opening of the medium-frequency melting furnace is open inside the vacuum chamber.

[0024] The crystallizer is located inside the vacuum chamber, with an inlet and an outlet at each end. The inlet of the crystallizer is connected to the water inlet of the medium-frequency melting furnace. The crystallizer is a water-cooled horizontal continuous casting crystallizer.

[0025] The billet pulling machine is located outside the vacuum chamber. One end of the billet pulling machine is equipped with a dummy bar. The axis of the dummy bar is arranged to coincide with the axis of the inner hole of the vacuum lock. The dummy bar is directly opposite the outlet of the crystallizer and is used to pull out the billet.

[0026] The bottom blowing device is installed at the mounting port of the medium-frequency melting furnace and is used to blow inert gas into the inner cavity of the medium-frequency melting furnace.

[0027] The internal gas injection device is connected to the gas injection port of the vacuum lock and is used to inject inert gas into the internal hole of the vacuum lock.

[0028] A further technical solution of this utility model is as follows: the bottom blowing device includes a permeable brick, a steel pipe, and an air inlet pipe A; the permeable brick is sealed and fixedly installed in the installation port of the medium-frequency melting furnace, and the permeable brick has the characteristics of isolating molten steel and allowing air to pass through. The upper end of the permeable brick is located in the inner cavity of the medium-frequency melting furnace, and the lower end of the permeable brick is located outside the medium-frequency melting furnace; the upper end of the steel pipe is fixedly connected to the lower end of the permeable brick; one end of the air inlet pipe A is connected to the lower end of the steel pipe, and the other end is connected to a gas source for providing inert gas.

[0029] A further technical solution of the utility model is that the inner hole gas injection device comprises an exhaust pipe and an air inlet pipe B; one end of the exhaust pipe is hermetically and fixedly installed on the exhaust hole of the vacuum lock, and the other end is communicated with the atmosphere; one end of the air inlet pipe B is hermetically and fixedly installed on the gas injection hole of the vacuum lock, and the other end is communicated with a gas source for providing inert gas.

[0030] The utility model has the following advantages compared with the prior art:

[0031] 1. As a piece of equipment supporting the process of "medium-frequency melting in vacuum environment + inert gas protection horizontal continuous casting", it is used for the manufacture of superalloy welding wires, realizing the short-process, continuous and low-cost production of superalloy welding wires. The short process is reflected in: the electroslag remelting and forging processes are omitted, which is equivalent to shortening the core processes before post-treatment. The continuity is reflected in: the core processes before post-treatment achieve seamless docking and continuous discharging. The low cost is reflected in: the shortening and continuity of the process flow reduce the labor cost, waste and loss.

[0032] 2. As an important component in the manufacturing system, the vacuum lock realizes the dynamic seal during the horizontal continuous casting process; when the dummy bar passes through the first sleeve, a seal is formed between the dummy bar and the sealing ring. When the billet enters the first sleeve, the part of the sealing ring that interferes with the billet is burned and vaporized at high temperature. The billet transfers heat to the expansion ring, causing the expansion ring to expand thermally and the inner hole size to shrink. After the inner hole size of the expansion ring shrinks, it fits the outer diameter size of the billet to ensure the dynamic seal effect during the pulling process of the billet.

[0033] 3. As the friction contact time between the billet and the expansion ring increases, the inner hole wall of the expansion ring gradually wears, and there may be a seal failure between the two. At this time, the compression nut can be adjusted to increase the pressing force, further compressing the axial length (or thickness) of the expansion ring, so that the inner hole diameter of the expansion ring is further reduced to offset the wear amount of the inner hole of the expansion ring.

[0034] 4. The medium-frequency induction melting process effectively reduces the levels of gaseous elements (O, N, and H) and sulfur in the molten steel, significantly improving its purity. This results in the ingots produced by subsequent horizontal continuous casting having the same specifications as those manufactured using the traditional "vacuum induction melting + electroslag remelting" process. The principle behind improving steel purity is as follows: In a vacuum environment, a) the solubility of dissolved oxygen, dissolved nitrogen, and dissolved hydrogen in the molten steel decreases and they precipitate. Bubbles generated by bottom-blown inert gas (argon gas blown upwards from the bottom of the medium-frequency melting furnace) absorb these precipitated gases as they rise in the molten steel, causing them to grow larger. When the bubbles reach the surface of the molten steel, they are released into the vacuum chamber and removed by vacuum extraction; b) the bubbles generated by bottom-blown inert gas (argon gas blown upwards from the bottom of the medium-frequency melting furnace) create a local vacuum in the molten steel. A pressure difference is formed at the interface between the bubbles and the molten steel, causing dissolved oxygen and dissolved nitrogen in the molten steel to be continuously drawn into the bubbles, making the bubbles grow larger. When the bubbles reach the surface of the molten steel, they are discharged into the vacuum chamber and removed by vacuuming. c. Some suspended inclusions exist in the molten steel. When the bubbles come into contact with the inclusions, they adsorb the inclusions onto the bubble walls. As the bubbles rise, they are eventually transferred to the surface of the molten steel. d. The sulfur element in the molten steel burns off and vaporizes during the smelting process, and is discharged into the vacuum chamber and removed by vacuuming.

[0035] 5. It employs measures such as bottom argon stirring and the creation of a vacuum environment to ensure the high purity of the molten steel. Furthermore, both smelting and horizontal continuous casting are completed within the vacuum chamber (under vacuum conditions), effectively solving the problem of secondary oxidation of the molten steel. The vacuum chamber achieves vacuum environment construction through structural design: a) An operation port is provided at the upper end of the vacuum chamber for temperature measurement, sampling, or material replenishment. When no material replenishment or temperature measurement / sampling operation is performed, the balance valve is closed to ensure the airtightness of the entire vacuum chamber 1. When performing material replenishment or temperature measurement / sampling operations, a sealed feeder (a prior art technology, therefore not shown in the figure) or a temperature sampler (a prior art technology, therefore not shown in the figure) is sealed and connected to the operation port before the balance valve is opened. b) A sealing ring and an expansion ring are provided in the inner hole of the vacuum lock. The sealing ring matches the ingot guide rod and is used to seal when the ingot guide rod passes through the inner hole of the vacuum lock. The expansion ring matches the billet and is used to seal when the billet passes through the inner hole of the vacuum lock. When the billet has not entered the inner hole of the vacuum lock, the expansion ring is at room temperature. The inner diameter of the expansion ring is larger than the outer diameter of the billet and the dummy rod, so it will not interfere with the movement of the dummy rod. When the billet enters the inner hole of the vacuum lock, it vaporizes the sealing ring and transfers heat to the expansion ring, causing the expansion ring to expand. This causes the inner diameter of the expansion ring to shrink until it matches the outer diameter of the billet. At this point, a dynamic seal is formed between the inner hole of the expansion ring and the outer surface of the billet.

[0036] 6. During the horizontal continuous casting process, an internal gas injection device is used to inject inert gas into the inner hole of the vacuum lock, which prevents outside air from entering the vacuum chamber through the gap between the ingot rod and the inner hole of the vacuum lock or between the billet and the inner hole of the vacuum lock, thus oxidizing the molten steel.

[0037] The present invention will be further described below with reference to the figures and embodiments. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the vacuum lock structure;

[0039] Figure 2 A schematic diagram of a short-process high-temperature alloy welding wire manufacturing system;

[0040] Figure 3 A flowchart of the manufacturing process for the high-temperature alloy welding wire that is compatible with this utility model;

[0041] Figure 4 This is a flowchart of the existing high-temperature alloy welding wire production process.

[0042] Legend: Vacuum chamber 1; Chamber body 11; Top cover 12; Operating port 13; Balance valve 14; Negative pressure extraction port 15; Vacuum lock 2; First sleeve 21; Injection port 211; Exhaust port 212; Flange A 213; Expansion ring 22; Sealing ring 23; Second sleeve 24; Flange B 241; Screw 25; Nut 26; Medium frequency melting furnace 3; Opening 31; Water inlet 32; Crystallizer 4; Roller 5; Permeable brick 61; Steel pipe 62; Inlet pipe A 63; Exhaust pipe 71; Inlet pipe B 72. Detailed Implementation Example 1

[0043] like Figure 1 As shown, vacuum lock 2 is used for dynamic sealing when the ingot rod and the billet pass through its inner hole; it has an inner hole through which the billet and the ingot rod pass for sealing, and an air injection hole and an air exhaust hole connected to the inner hole are provided on its exterior.

[0044] Vacuum lock 2 includes a first sleeve 21, an expansion ring 22 (packing), a sealing ring 23, and a clamping assembly.

[0045] The first sleeve 21 is a sleeve shape with openings at both ends. Its inner hole includes a middle hole section and end holes on both sides of the middle hole section. An annular stepped surface is provided between the middle hole section and the two end holes. The diameter of the middle hole section is smaller than that of the two end holes. The outer surface of the first sleeve 21 is provided with an air injection hole 211 and an exhaust hole 212 connected to the middle hole section. A flange A213 is welded to both ends of the first sleeve 21. A plurality of threaded holes are provided on the flange A213 in an annular arrangement.

[0046] At least three expansion rings 22 are stacked face to face to form a group. Two groups of expansion rings 22 are respectively installed in the two end holes of the first sleeve 21. The inner holes of all expansion rings 22 in each group of expansion rings 22 are connected in sequence to form a billet sealing section.

[0047] Two sealing rings 23 are respectively installed in the two end sections of the first sleeve 21, and the end face of the sealing ring 23 contacts the outermost expansion ring 22 in the end section (the outermost expansion ring 22 is the one farthest from the annular step surface). The inner hole of the sealing ring 23 forms the sealing section of the guide rod. Two sets of clamping assemblies are respectively installed in the end sections at both ends of the first sleeve 21, which are used to press the sealing ring 23 and a set of expansion rings 22 in the end sections onto the annular step surface.

[0048] The clamping assembly includes a second sleeve 24, screws 25, and nuts 26. The front end of the second sleeve 24 is inserted into the end hole of the first sleeve 21, with its front end face contacting the end face of the sealing ring 23. A flange B241 is welded to the rear end face of the second sleeve 24. Flange B241 has through holes corresponding to the threaded holes on flange A213 and in the same number. The number of screws 25 and nuts 26 is the same as the number of through holes on flange B241. All screws 25 pass through their respective through holes on the second sleeve 24 and are screwed into the corresponding threaded holes on the first sleeve 21. Multiple nuts 26 are threaded onto each screw 25 and abut against flange B241. By adjusting the nuts 26, the front end of the second sleeve 24 presses the sealing ring 23 and a set of expansion rings 22 in the end hole section against the annular stepped surface.

[0049] Preferably, the vacuum lock 2 is made of a composite material with expanded graphite (flexible graphite) as the main component, supplemented by metal wires or ceramic fibers to enhance mechanical strength and wear resistance. The metal wires (stainless steel wires or nickel-based alloy wires) are spirally wound or woven and embedded in the expanded graphite matrix, forming a skeleton structure that provides tensile and compressive strength, while the expanded graphite fills the gaps and provides a sealing function. The ceramic fibers (alumina or silicon carbide fibers) are mixed into the expanded graphite matrix in the form of chopped fibers, or woven into a mesh layer and alternately layered with graphite. The ceramic fibers are bonded to the expanded graphite matrix through mechanical interlocking and high-temperature sintering.

[0050] like Figure 2 As shown, the short-process high-temperature alloy welding wire manufacturing system is based on the above-mentioned vacuum lock; it includes a vacuum chamber 1, a vacuum lock 2, a medium-frequency melting furnace 3, a crystallizer 4, a billet pulling machine 5, a bottom blowing device, and an inner hole gas injection device.

[0051] Vacuum chamber 1 includes a chamber body 11 with an open top and a cover 12 sealed at the open top of the chamber body 11. The chamber body 11 has an inner cavity for accommodating a medium-frequency melting furnace and a crystallizer. The chamber body 11 has a negative pressure exhaust port 15 connected to the inner cavity. The negative pressure exhaust port 15 is connected to a vacuum pump (not shown in the figure) located outside the vacuum chamber 1 through a gas pipeline. The cover 12 has an operation port 13 for adding materials and taking temperature samples. The operation port 13 has a balance valve 14 (used to balance the pressure on both sides of the valve).

[0052] Vacuum lock 2 is fixedly installed on the side wall of vacuum chamber 1. It has an inner hole through which the casting billet and the ingot rod pass. The two ends of the inner hole are respectively connected to the inner cavity of vacuum chamber 1 and the outside of vacuum chamber 1. The outside of the inner hole is provided with an air injection hole connected to the inner hole and an air exhaust hole connected to the inner hole.

[0053] The medium-frequency melting furnace 3 is located inside the vacuum chamber 1. The medium-frequency melting furnace 3 has an opening 31 at the upper end, a water inlet 32 ​​at the lower end, and an installation port at the bottom. The opening 31 of the medium-frequency melting furnace 3 is open inside the vacuum chamber 1.

[0054] The crystallizer 4 is located inside the vacuum chamber 1. The crystallizer 4 has an inlet and an outlet at both ends, and the inlet of the crystallizer 4 is connected to the water outlet of the medium-frequency melting furnace 3. The crystallizer 4 is a water-cooled horizontal continuous casting crystallizer.

[0055] The billet pulling machine 5 is located outside the vacuum chamber 1. One end of the billet pulling machine 5 is equipped with a siphon rod. The axis of the siphon rod coincides with the axis of the inner hole of the vacuum lock 2. The siphon rod is directly opposite the outlet of the crystallizer 4 and is used to pull out the billet.

[0056] A bottom-blowing device is installed at the mounting port of the medium-frequency melting furnace to blow inert gas into the furnace's interior. The bottom-blowing device includes a permeable brick 61, a steel pipe 62, and an inlet pipe A63. The permeable brick 61 is sealed and fixedly installed in the mounting port of the medium-frequency melting furnace 3. The permeable brick has the property of isolating molten steel and allowing air to pass through. The upper end of the permeable brick is located inside the furnace's interior, and the lower end is located outside the furnace. The upper end of the steel pipe 62 is fixedly connected to the lower end of the permeable brick 61. One end of the inlet pipe A61 is connected to the lower end of the steel pipe 62, and the other end is connected to a gas source for providing inert gas.

[0057] An internal gas injection device is connected to the gas injection port 21 of the vacuum lock 2 and is used to inject inert gas into the internal bore of the vacuum lock 2. The internal gas injection device includes an exhaust pipe 71 and an inlet pipe B72. One end of the exhaust pipe 71 is sealed and fixedly installed on the exhaust port 212 of the vacuum lock 2, and the other end is open to the atmosphere; one end of the inlet pipe B72 is sealed and fixedly installed on the gas injection port 211 of the vacuum lock 2, and the other end is connected to a gas source for providing inert gas.

[0058] A short-process high-temperature alloy welding wire manufacturing system is used for manufacturing high-temperature alloy welding wire. Taking the high-temperature alloy of grade K418 as an example, the process flow for manufacturing welding wire is briefly described.

[0059] The steps are as follows:

[0060] S01, induction melting in a vacuum environment:

[0061] A. Raw material feeding and vacuuming: Before feeding the high-temperature alloy raw materials into the furnace, they are weighed again and the proportion of the batching is checked. Finally, according to the proportion of the finished product, additional alloy materials are selected and added. The high-temperature alloy raw materials and carbon used for deoxidation are fed into the medium-frequency melting furnace, and the vacuum chamber of the medium-frequency melting furnace is evacuated.

[0062] B. Melting: Start the medium-frequency melting furnace and gradually increase the power to the melting temperature (1560±5℃) using a stepped "increase power-hold power" method. The melting process should last at least 190 minutes, ensuring that the alloy material is completely liquefied within the first 40 minutes of the melting process. During the above process, the following events occur: ①. The high-temperature alloy raw material is melted into molten steel; ②. Oxygen in the molten steel is replaced by carbon, producing carbon oxide gas, which is discharged into the vacuum chamber and removed by vacuuming; ③. The solubility of nitrogen and hydrogen in the molten steel decreases under vacuum conditions, and they are released as gases, discharged into the vacuum chamber, and removed by vacuuming; ④. Sulfides in the molten steel are burned off and vaporized during the melting process, discharged into the vacuum chamber, and removed by vacuuming.

[0063] C. Refining: Adjust the power of the medium-frequency melting furnace to bring the molten steel temperature to the preset refining temperature of 1580±5℃, and simultaneously perform the following operations: ①. Hold for 15 minutes to further remove oxygen, nitrogen, hydrogen, and sulfur elements from the molten steel; ②. Blow inert gas into the inner cavity of the medium-frequency melting furnace through the bottom blowing device. As the generated bubbles rise, they absorb the precipitated gas, causing the bubbles to grow larger. When the bubbles reach the surface of the molten steel, they are discharged into the vacuum chamber and removed by vacuuming.

[0064] S02, inert gas protected horizontal continuous casting:

[0065] After reducing the power of the medium-frequency melting furnace and allowing the molten steel temperature to reach the initial casting temperature of 1500±10℃, stop vacuuming and simultaneously perform the following operations: ① Bottom-blowing inert gas: Maintain bottom-blowing inert gas to cover the surface of the molten steel with protective gas, preventing air from seeping into the vacuum chamber through gaps and contacting the molten steel, thus oxidizing it; ② Ingot pulling: The medium-frequency melting furnace discharges refined molten steel through the nozzle, and the molten steel flows into the interior of the crystallizer located in the vacuum chamber, forming the billet shell; the ingot pulling machine located outside the vacuum chamber drives the ingot pulling rod to move horizontally, continuously pulling the billet from inside the crystallizer to the outside of the vacuum chamber, which is called ingot pulling. The pulled billet is cut to the required length (i.e., the length required by the process), thus obtaining the high-temperature alloy welding wire semi-finished product.

[0066] S03, Post-processing:

[0067] The high-temperature alloy welding wire semi-finished product is peeled off on a lathe to remove surface defects (inherent defects of horizontal continuous casting: cold grids) on its outer cylindrical surface; then it is processed by hot continuous rolling to prepare wire rods that meet the subsequent drawing requirements; the wire rods are then processed by solution treatment, pickling, rough drawing and fine drawing to gradually reduce the diameter of the welding wire to meet the process requirements, thus obtaining the high-temperature alloy welding wire finished product.

[0068] Preferably, in step S01, the vacuum level in the vacuum chamber is maintained below 8 Pa.

[0069] Preferably, in step S01, the static air height during molten steel melting is ≥20cm to ensure that the molten steel does not overflow when it is agitated and fluctuated by inert gas.

[0070] Preferably, provided that the high-temperature alloy welding wire contains active elements (including Al, Ti, Zr or Hf), step S01 also includes step D following step C; D, feeding: the medium-frequency melting furnace is de-energized and cooled to 1380°C, and then active element material is added by vacuum feeding (vacuum feeding is achieved by using a vacuum feeder, the structure and principle of which are existing technologies).

[0071] Preferably, in step S02, the billet pulling speed is 0.5-1.5 m / min.

[0072] Preferably, in step S02, the vacuum level in the vacuum chamber is maintained below 65000 Pa.

[0073] Preferably, in step S02, the operation performed simultaneously also includes: ③. Injecting inert gas into the inner hole of the vacuum lock: The dummy bar and the billet pass through the inner hole of the vacuum lock located on the outer wall of the vacuum chamber, and the dummy bar and the billet form an annular sealing surface with the vacuum lock. Inert gas is injected into the inner hole of the vacuum lock through the inner hole gas injection device to prevent outside air from entering the vacuum chamber cavity through the gap between the dummy bar and the inner hole of the vacuum lock or between the billet and the inner hole of the vacuum lock, thereby oxidizing the molten steel.

[0074] Preferably, in step S02, the initial position of the dummy bar is such that one end is outside the vacuum chamber, and the other end passes through the vacuum lock on the outer wall of the vacuum chamber and is located inside the vacuum chamber, extending into the crystallizer; during the horizontal continuous casting process, one end of the billet passes through the vacuum lock on the outer wall of the vacuum chamber and is located inside the vacuum chamber, while the other end is outside the vacuum chamber; when the dummy bar moves in the vacuum lock, an annular sealing surface is formed between the dummy bar and the vacuum lock, and when the billet moves through the vacuum lock, an annular sealing surface is formed between the billet and the vacuum lock.

[0075] Preferably, in step S03, the peeling depth is based on the removal of defects on the outer surface of the high-temperature alloy welding wire semi-finished product.

[0076] Preferably, in steps S01-S02, the inert gas is argon with a purity of 99.99% or higher, krypton with a purity of 99.99% or higher, or helium with a purity of 99.99% or higher.

[0077] Preferably, in steps S01-S02, the amount of bottom-blown inert gas is determined by the fact that the surface of the molten steel fluctuates but the molten steel does not leak out.

[0078] The following events occur during the billet drawing process in step S02 above: First, as the dummy bar passes through the inner hole of the first sleeve 21, a seal is formed between the dummy bar and the inner holes of the two sealing rings 23. Then, when the billet enters the inner hole of the first sleeve 21, the part of the sealing ring that interferes with the billet (i.e., the central hole of the sealing ring) is burned and vaporized by the high temperature of the billet. The billet transfers heat to the expansion ring 22, causing the expansion ring 22 to expand due to heat and its inner hole size to shrink. After the inner hole size of the expansion ring 23 shrinks, it matches the outer diameter of the billet, ensuring the dynamic sealing effect during the billet drawing process. Furthermore, since the expansion ring 22 is pressed tightly by the clamping assembly in the thickness direction (axial direction), there is no expansion margin left, so the expansion ring 22 can only expand in the radial direction, making the shrinkage of the inner hole size of the expansion ring 22 even greater.

Claims

1. A vacuum lock for dynamic sealing with a dummy bar and a strand passing through its bore; characterized by: It has an inner hole through which the casting billet and the ingot rod pass for sealing, and an air injection hole and an air vent hole connected to the inner hole on the outside. A vacuum lock includes a first sleeve, expansion rings, sealing rings, and a clamping assembly. The first sleeve is a sleeve-shaped structure with open ends. Its inner bore includes a central section and end sections on both sides of the central section. An annular stepped surface is provided between the central section and the two end sections. The diameter of the central section is smaller than that of the two end sections. An air injection hole and an air vent, both connected to the central section, are provided on the outer surface of the first sleeve. A flange A is welded to each end face of the first sleeve, and flange A has a plurality of annularly distributed threaded holes. At least three expansion rings are stacked face-to-face to form a group. Two groups of expansion rings are installed in the two end sections of the first sleeve, and the inner bores of all expansion rings in each group are sequentially connected to form a casting sealing section. Two sealing rings are installed in the two end sections of the first sleeve, with the end face of the sealing rings aligned with the outermost end section. The expansion rings are in contact, and two sets of clamping assemblies are respectively installed in the end holes at both ends of the first sleeve. They are used to press the sealing ring and a set of expansion rings in the end holes onto the annular step surface. The clamping assembly includes a second sleeve, screws, and nuts. The front end of the second sleeve is inserted into the end hole of the first sleeve, and its front end face contacts the end face of the sealing ring. A flange B is welded to the rear end face of the second sleeve. The flange B has through holes that correspond to the positions of the threaded holes on the flange A and have the same number. The number of screws and nuts is the same as the number of through holes on the flange B. All screws pass through the through holes on the second sleeve and are screwed into the corresponding threaded holes on the first sleeve. Multiple nuts are threaded onto each screw and abut against the flange B. By adjusting the nuts, the front end of the second sleeve presses the sealing ring and a set of expansion rings in the end holes onto the annular step surface.

2. A short process superalloy wire manufacturing system based on the vacuum lock of claim 1 ; characterized by: It includes a vacuum chamber, a vacuum lock, a medium-frequency melting furnace, a crystallizer, a billet puller, a bottom blowing device, and an internal gas injection device; The vacuum chamber includes a chamber body with an open top and a top cover that is sealed and installed at the open top of the chamber body. The chamber body has an inner cavity for accommodating the medium-frequency melting furnace and the crystallizer. The chamber body has a negative pressure exhaust port that connects to the inner cavity. The top cover has an operating port for adding materials and taking temperature samples. The operating port has a balance valve inside. The vacuum lock is fixedly installed on the side wall of the vacuum chamber. It has an inner hole through which the casting billet and the ingot rod pass. The two ends of the inner hole are respectively connected to the inner cavity of the vacuum chamber and the outside of the vacuum chamber. The outside of the lock has an injection hole connected to the inner hole and an exhaust hole connected to the inner hole. The medium-frequency melting furnace is located inside the vacuum chamber. The upper end of the medium-frequency melting furnace is open, the lower end is a water inlet, and the bottom is an installation port. The opening of the medium-frequency melting furnace is open inside the vacuum chamber. The crystallizer is located inside the vacuum chamber, with an inlet and an outlet at each end. The inlet of the crystallizer is connected to the water inlet of the medium-frequency melting furnace. The crystallizer is a water-cooled horizontal continuous casting crystallizer. The billet pulling machine is located outside the vacuum chamber. One end of the billet pulling machine is equipped with a siphon rod. The axis of the siphon rod coincides with the axis of the inner hole of the vacuum lock. The siphon rod is directly opposite the outlet of the crystallizer and is used to pull out the billet. The bottom blowing device is installed at the mounting port of the medium-frequency melting furnace and is used to blow inert gas into the inner cavity of the medium-frequency melting furnace. The internal gas injection device is connected to the gas injection port of the vacuum lock and is used to inject inert gas into the internal hole of the vacuum lock.

3. The short process superalloy wire manufacturing system of claim 2, wherein: The bottom blowing device includes a permeable brick, a steel pipe, and an air inlet pipe A. The permeable brick is sealed and fixedly installed in the installation port of the medium-frequency melting furnace. The permeable brick has the characteristics of isolating molten steel and allowing air to pass through. The upper end of the permeable brick is located in the inner cavity of the medium-frequency melting furnace, and the lower end of the permeable brick is located outside the medium-frequency melting furnace. The upper end of the steel pipe is fixedly connected to the lower end of the permeable brick. One end of the air inlet pipe A is connected to the lower end of the steel pipe, and the other end is connected to a gas source for providing inert gas.

4. The short process superalloy wire manufacturing system of claim 3, wherein: The internal gas injection device includes an exhaust pipe and an inlet pipe B; one end of the exhaust pipe is sealed and fixedly installed on the exhaust port of the vacuum lock, and the other end is connected to the atmosphere; one end of the inlet pipe B is sealed and fixedly installed on the gas injection port of the vacuum lock, and the other end is connected to a gas source for providing inert gas.

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