Beryllium copper alloy vacuum melting furnace building and baking method

Abstract

The invention discloses a beryllium copper alloy vacuum melting furnace building and baking method, and belongs to the technical field of beryllium copper alloys. The furnace building method comprises the following steps: preparing daub in which the mass content of castable is 5-8%, and uniformly smearing the daub on the inner surface of an induction coil of a furnace wall to form a daub layer concentric with the induction coil; mica paper, a stainless steel wire net, a furnace leakage alarm signal line and ceramic fiber cloth are sequentially laid in the induction coil coated with the daub; a furnace leakage alarm signal line is placed at the bottom of the furnace, and dry vibration materials are added in at least three layers so that the height of the bottom of the furnace can be 150-200 mm; a crucible is placed in an induction coil, and dry vibration materials are added in at least six layers till the distance between the dry vibration materials and the furnace mouth is 80-100 mm; and a refractory material which is 50-60 mm thick and can resist the temperature higher than 1650 DEG C is laid at a pouring nozzle, the pouring nozzle is put into a chute and filled with the refractory material which can resist the temperature higher than 1650 DEG C for fixing, and then sealing and molding are conducted. The stability and leakage resistance of the furnace body can be improved, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of beryllium copper alloys, and particularly relates to a beryllium copper alloy vacuum smelting furnace building and baking method. BACKGROUND

[0002] Beryllium copper alloys are widely used in key fields such as aerospace and electronics due to their excellent performance such as high strength and high electrical conductivity. The vacuum smelting furnace is a key equipment for the production of beryllium copper alloys, and the quality of the furnace building directly affects the stability of alloy smelting and product quality.

[0003] The traditional furnace building process has the following problems: the coil slurry layer has low building precision, the uneven thickness of the mortar leads to poor coil concentricity, and the electromagnetic induction efficiency is affected; the leakage furnace protection structure is simple, and single-layer insulation materials are often used, which is easy to cause leakage due to high temperature or mechanical damage, and the alarm sensitivity is insufficient; the dry vibration material building parameters of the furnace bottom and furnace wall are not standardized, the thickness of each layer and the tamping time are controlled randomly, which leads to insufficient furnace body strength and short service life; the curing process of the mortar is unreasonable, and the mortar is not fully cured, which is easy to crack or peel off. SUMMARY

[0004] To solve the above technical problems, the application provides a beryllium copper alloy vacuum smelting furnace building and baking method, which improves the stability, leakage resistance and service life of the furnace body by precisely controlling the parameters and structure of each building link.

[0005] The first aspect of the application provides a beryllium copper alloy vacuum smelting furnace building method, which comprises: Step S1, cleaning the furnace wall and the furnace bottom; Step S2, adjusting the mortar with a quality content of 5-8%, uniformly applying the mortar to the inner surface of the induction coil of the furnace wall to form a mortar layer concentric with the induction coil, and then performing air curing; the air curing period satisfies: ≥28h for new building or major repair, ≥8h for minor repair, and infrared lamps are continuously heated and baked during the air curing period; Step S3, sequentially laying mica paper, stainless steel wire mesh, leakage alarm signal line and ceramic fiber cloth in the induction coil after applying the mortar, cutting the protruding mica paper and ceramic fiber cloth to be flush with the upper edge of the induction coil and extending outward, and pressing and fixing them on the top of the furnace body; Step S4, placing the leakage alarm signal line in the furnace bottom, and adding dry vibration material in at least three layers to make the height of the furnace bottom 150-200mm; Wherein, the amount of each layer of material is ≤100kg, each layer needs to be leveled, degassed and tamped after leveling, the tamping time is ≥10min each time, and the vibration time is 10-20min after tamping each time; Step S5, placing the crucible in the induction coil obtained in step S3, and adding dry vibration material in at least six layers to the position 80-100mm away from the furnace opening. Wherein, the feeding amount of each layer is less than or equal to 100 kg, and each layer needs to be leveled, degassed and tamped after leveling, and the tamping time of each layer is greater than or equal to 20 minutes; In step S6, 50-60 mm thick refractory material with a temperature resistance greater than 1650 DEG C is laid at the pouring nozzle, put into the chute and filled with refractory material with a temperature resistance greater than 1650 DEG C, and then the refractory material with a temperature resistance greater than 1650 DEG C is used for layered sealing to a height of more than 100 mm above the furnace mouth and then shaping.

[0006] According to the beryllium copper alloy vacuum smelting furnace building method of the first aspect of the present application, the specific process of cleaning the furnace wall and the furnace bottom in the step S1 comprises: stripping the furnace wall refractory material and cleaning the furnace bottom.

[0007] According to the beryllium copper alloy vacuum smelting furnace building method of the first aspect of the present application, the furnace building method further comprises: before the step S2, controlling the flow of the cooling water circuit to be 3-4.5 m 3 / h and judging whether the insulation resistance of the detection induction coil is not less than 5500 Ω; When the insulation resistance of the detection induction coil is less than 5500 Ω, the induction coil is repaired by laser welding or replaced with a new induction coil.

[0008] According to the beryllium copper alloy vacuum smelting furnace building method of the first aspect of the present application, in the step S2, the thickness of the mortar layer is 4-6 mm, and the thickness error of each part is ±0.5 mm.

[0009] According to the beryllium copper alloy vacuum smelting furnace building method of the first aspect of the present application, in the step S3, the mica paper is laid in 3-5 layers, and the thickness of each layer of mica paper is 0.35-0.45 mm; The mesh opening of the stainless steel wire mesh is a square mesh opening with a side length of 7-9 mm, and the diameter of a single stainless steel wire in the stainless steel wire mesh is 0.55-0.65 mm; The ceramic fiber cloth is laid in 3-5 layers, and the thickness of each layer of ceramic fiber cloth is 1.5-2 mm.

[0010] According to the beryllium copper alloy vacuum smelting furnace building method of the first aspect of the present application, in the step S3, the stainless steel wire mesh is laid close to the mica paper.

[0011] According to the beryllium copper alloy vacuum smelting furnace building method of the first aspect of the present application, in the step S4, the leakage alarm signal line of the furnace bottom is 20-30 mm higher than the refractory material of the furnace bottom; In the step S5, the crucible is a graphite crucible, the crucible is concentric with the induction coil, and the crucible opening is flush with the upper edge of the induction coil; In steps S4 and S5, degassing and tamping are carried out simultaneously. A degassing fork is inserted into the furnace bottom for degassing, and the insertion depth of the degassing fork is ≤20mm.

[0012] According to the furnace construction method of the beryllium copper alloy vacuum melting furnace according to the first aspect of the present invention, in step S6, the spout is cleaned before the refractory material is laid at the spout. The chute is a graphite chute; After sealing, the mica paper and ceramic fiber cloth protruding above the furnace opening are cut.

[0013] The second aspect of the present invention provides a beryllium copper alloy vacuum melting furnace constructed using the aforementioned beryllium copper alloy vacuum melting furnace construction method.

[0014] A third aspect of this invention provides a furnace drying method for the aforementioned beryllium copper alloy vacuum melting furnace, the furnace drying method comprising: The beryllium copper alloy vacuum melting furnace that has been built is subjected to air curing for 8-12 hours, followed by electric baking with a heating rate of 48-52℃ / h. After baking, the furnace is dried with the material in it. Each batch of raw material is ≤200kg until the furnace is full. After all the material has melted, it is kept at a temperature of 0.4-0.6h before being taken out of the furnace and cast into furnace-dried ingots. Repeat the baking process with the material until the last baking ingot end face penetration test shows no defects.

[0015] The solution proposed in this invention has the following technical effects: This invention improves the concentricity of the mortar layer and coil by precisely constructing the coil slurry layer and standardizing curing with infrared lamp heating, thereby increasing the electromagnetic induction efficiency by more than 10%. It employs a multi-layered composite protective structure of mica paper, stainless steel wire mesh, and ceramic fiber cloth, combined with a furnace leakage alarm signal line, reducing the furnace leakage warning response time to less than 0.5 seconds and lowering the risk of furnace leakage by 90%. Strict control over the quantitative layering, degassing, and tamping time of the dry vibrating material at the furnace bottom and walls increases the furnace body's compressive strength by 20-30% and extends its service life from 80 to over 120 furnace cycles. The spout and sealing material use refractory materials with a temperature resistance greater than 1650℃ to shorten repair time by 55%.

[0016] Furthermore, the present invention combines a low-power baking oven method with a baking oven with material, which ensures the baking effect. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The first aspect of this invention provides a method for constructing a vacuum melting furnace for beryllium copper alloy, the method comprising: Step S1: Remove the refractory material from the furnace wall and clean the furnace bottom, controlling the cooling water flow rate to 3-4.5 m³ / h. 3 / h and determine whether the insulation resistance of the detection induction coil is not less than 5500Ω; When the insulation resistance of the induction coil is less than 5500Ω, the induction coil should be repaired by laser welding or replaced with a new induction coil.

[0019] Preferably, it is also necessary to ensure that the bottom support frame of the induction coil and the coil fixing plate are securely connected.

[0020] Step S2: Prepare a mortar with a casting material content of 5-8% by mass, and evenly apply the mortar to the inner surface of the induction coil on the furnace wall to form a mortar layer concentric with the induction coil. Then, perform air curing. The air curing cycle meets the following requirements: ≥28h for new construction or major repair, ≥8h for minor repair, and infrared lamps are used for continuous heating and baking during the air curing cycle.

[0021] Preferably, the thickness of the putty layer is 4-6 mm, and the thickness error at each location is ±0.5 mm.

[0022] Step S3: After applying the putty, lay mica paper, stainless steel wire mesh, furnace leakage alarm signal line and ceramic fiber cloth in sequence inside the induction coil. Cut the protruding mica paper and ceramic fiber cloth at intervals until they are flush with the upper edge of the induction coil and extend them outwards, press them on the top of the furnace body and fix them.

[0023] Preferably, the mica paper is laid in 3-5 layers, and the thickness of each layer of mica paper is 0.35-0.45mm; The stainless steel wire mesh has a square mesh opening with a side length of 7-9mm, and the diameter of a single stainless steel wire in the stainless steel wire mesh is 0.55-0.65mm. The ceramic fiber cloth is laid in 3-5 layers, and the thickness of each layer of ceramic fiber cloth is 1.5-2mm.

[0024] Preferably, the stainless steel wire mesh is laid close to the mica paper.

[0025] Specifically, the mica paper is 1500×1000mm in size, the stainless steel wire mesh is 800-1500×2200mm in size, and the ceramic fiber cloth is 1500×1000mm in size.

[0026] Step S4: Place the furnace leakage alarm signal line at the bottom of the furnace, and add dry vibrating material in at least three layers to make the furnace bottom height 150-200mm; the amount of material added to each layer is ≤100kg, and each layer needs to be scraped, degassed and compacted, with each compaction time ≥10min, and vibration for 10-20min after each compaction.

[0027] Preferably, the furnace leakage alarm signal line placed at the bottom of the furnace is 20-30mm higher than the refractory material at the bottom of the furnace.

[0028] Preferably, degassing and tamping are carried out simultaneously, and a degassing fork is inserted into the furnace bottom for degassing, with the insertion depth of the degassing fork ≤20mm.

[0029] Specifically, after each layer of dry vibratory material is laid, the height of at least four points must be measured and the degassing and compaction parameters recorded.

[0030] Step S5: Place a crucible inside the induction coil obtained in step S3, and add dry vibrating material in at least six layers until it reaches 80-100mm from the furnace opening; wherein, the amount of material added in each layer is ≤100kg, and each layer needs to be scraped flat, degassed and compacted, and the compaction time is ≥20min each time.

[0031] Preferably, the crucible is a graphite crucible, the crucible is concentric with the induction coil, and the mouth of the crucible is flush with the upper edge of the induction coil.

[0032] Preferably, degassing and tamping are carried out simultaneously, and a degassing fork is inserted into the furnace bottom for degassing, with the insertion depth of the degassing fork ≤20mm.

[0033] Specifically, after each layer of dry vibratory material is laid, the height of at least four points must be measured and the degassing and compaction parameters recorded.

[0034] Step S6: Lay a 50-60mm thick layer of refractory material with a temperature resistance greater than 1650℃ at the spout, place the graphite chute in and fill it with refractory material with a temperature resistance greater than 1650℃ to fix it, and then use refractory material with a temperature resistance greater than 1650℃ to seal the chute in layers until it is more than 100mm above the furnace opening before shaping.

[0035] Preferably, the spout is cleaned before the refractory material is laid at the spout.

[0036] Specifically, before using refractory materials with a temperature resistance greater than 1650℃ for layered sealing, the refractory materials need to be cut into granules. During the layered sealing process, each layer is compacted. After sealing, the mica paper and ceramic fiber cloth that protrude above the furnace opening are cut.

[0037] The second aspect of the present invention provides a beryllium copper alloy vacuum melting furnace constructed using the aforementioned beryllium copper alloy vacuum melting furnace construction method.

[0038] A third aspect of this invention provides a furnace drying method for the aforementioned beryllium copper alloy vacuum melting furnace, the furnace drying method comprising: The beryllium copper alloy vacuum melting furnace that has been built is subjected to air curing for 8-12 hours, followed by electric baking with a heating rate of 48-52℃ / h. After baking, the furnace is dried with the material in it. Each batch of raw material is ≤200kg until the furnace is full. After all the material has melted, it is kept at a temperature of 0.4-0.6h before being taken out of the furnace and cast into furnace-dried ingots. Repeat the baking process with the material until the last baking ingot end face penetration test shows no defects.

[0039] Example 1 Step 1: Pre-furnace inspection Remove the refractory material from the furnace wall and clean the debris from the furnace bottom, then remove the graphite crucible; use a megohmmeter to test the insulation resistance of the induction coil, ensuring it is ≥5500Ω; if there is a local insulation abnormality that can be repaired, repair it and retest; if the coil is damaged or the insulation is irreparable, remove the inductor, repair it, and then reinstall it; check the cooling water flow rate to be 3-3.5m³ / h. 3 / h, confirm that the water-cooled cable and connecting pipe are sealed without leakage; check the tightness of the screws and the integrity of the solder joints of the bottom support frame and the coil fixing plate of the coil.

[0040] Step 2: Coil grout layer construction The mass ratio of castable refractory to water is controlled at 6.5%. Water is added first, and then the mortar is prepared using a mixer. The mortar is evenly applied to the inter-turns and inner surface of the induction coil with a trowel, ensuring that the mortar layer is concentric with the induction coil. The thickness of the mortar layer is controlled at 5±0.5mm. After that, air curing is carried out. For newly built or major repairs, air curing is ≥32h, and infrared lamps are used for continuous heating and baking during the curing period. Step 3: Installation of furnace leakage protection and alarm devices Lay three 0.45mm thick 1500×1000mm mica sheets flat against the inner wall of the induction coil; roll up a 1000×2200mm non-magnetic stainless steel wire mesh (0.6mm diameter, 8×8mm mesh opening) and place it inside the induction coil, then unfold it and place it flat against the mica sheets; install the furnace leakage alarm signal line and test it to be normal; lay four 1.7mm thick 1500×1000mm ceramic fiber cloths flat against the stainless steel wire mesh; cut the protruding mica sheets and ceramic fiber cloths at intervals to be flush with the top edge of the coil and extend them outwards, pressing them onto the top of the furnace body and fixing them in place; Step 4: Furnace bottom construction Introduce furnace bottom alarm lines: The lower alarm line extends 20mm above the furnace bottom refractory material, using three lines extending spirally in three directions; the side alarm lines are connected to the furnace wall wire mesh; add dry vibrating material in layers (80kg per layer), after leveling, use a degassing fork to insert into the furnace bottom for degassing, with an insertion depth ≤15mm, and use a circular tamping head to tamp it down, with each tamping time being 15min. Tamping and degassing are carried out simultaneously, followed by 15min of vibration after tamping. After multiple layers of material addition, degassing, and tamping, the final furnace bottom height is controlled at 160mm.

[0041] Step 5: Furnace wall construction After leveling the furnace bottom, place the graphite crucible in the furnace and calibrate it to be concentric with the coil (spacing error ≤3mm). The crucible opening should be flush with the coil. Add dry vibrating material in layers (each layer ≤80kg). After leveling, use a degassing fork to insert into the furnace wall to degas the material to a depth ≤15mm. Use a furnace tamping head to tamp the material, with each tamping session lasting 20 minutes. Tamping and degassing are carried out simultaneously. After multiple layers of material addition, degassing, and tamping, continue until the material reaches 80mm from the furnace opening. Step 6: Pour spout and sealing masonry Clean the spout of any remaining debris, lay a 55mm thick layer of refractory material with a temperature resistance greater than 1650℃, tamp it down with a small hammer, and then level it with a scraper; place the graphite chute (aligned front and back, with uniform spacing left and right), fill the gaps with refractory material with a temperature resistance greater than 1650℃ and tamp it down to shape it; seal the opening with refractory material with a temperature resistance greater than 1650℃: cut it into granules and fill the gaps at the furnace opening, tamp it down layer by layer until it is 100mm above the furnace opening, and shape it with a scraper; cut the mica paper that extends above the furnace opening, and the furnace construction is complete.

[0042] Step 7: Oven baking After 10 hours of air curing, the furnace was electrically heated. The heating rate was 50℃ / h. At 500℃, the furnace was held for 18 hours; at 800℃, it was held for 12 hours; and at 1100℃, it was held for 6 hours. Electrolytic copper was added to the furnace in batches, with 150kg of raw material added per batch until the furnace was full. After all the electrolytic copper had melted, the furnace was held for 0.5 hours. The molten alloy was then poured into the furnace and cast. The ingots were subjected to end-face penetration testing. If defects such as porosity were found, the furnace heating process was repeated until the end-face penetration test of the ingots showed no defects. The furnace heating process was then complete. Subsequent verification showed that the furnace's service life increased from 80 heats to 120 heats; a furnace leakage alarm signal was detected.

[0043] Example 2 Step 1: Pre-furnace inspection Remove the refractory material from the furnace wall and clean the debris from the furnace bottom, then remove the graphite crucible; use a megohmmeter to test the insulation resistance of the induction coil, ensuring it is ≥6000Ω; if there is a local insulation abnormality that can be repaired, repair it and retest; if the coil is damaged or the insulation is irreparable, remove the inductor, repair it, and then reinstall it; check the cooling water flow rate to be 3.5-4m³ / h.3 / h, confirm that the water-cooled cable and connecting pipe are sealed without leakage; check the tightness of the screws and the integrity of the solder joints of the bottom support frame and the coil fixing plate of the coil.

[0044] Step 2: Coil grout layer construction The mass ratio of refractory to water should be controlled at 5%. Water should be added first, and then the mortar should be prepared using a mixer. The mortar should be evenly applied to the induction coil turns and inner surface with a trowel, ensuring that the surface is concentric with the coil, with a thickness of 4±0.5mm. After new construction or major repair, air curing should be carried out for at least 30 hours, and infrared lamps should be used for continuous heating and baking during the curing period. Step 3: Installation of furnace leakage protection and alarm devices Lay four 0.4mm thick 1500×1000mm mica sheets, flat against the inner wall of the coil; roll up an 800×2200mm non-magnetic stainless steel wire mesh (0.55mm diameter, 7×7mm mesh opening) and place it into the coil, then unfold it and place it against the mica sheets; install the furnace leakage alarm signal line and test it to be normal; lay five 1.5mm thick 1500×1000mm ceramic fiber cloths, flat against the stainless steel wire mesh; cut the protruding mica sheets and ceramic fiber cloth at intervals to be flush with the top edge of the coil, then extend them outwards, press them onto the top of the furnace body and fix them in place; Step 4: Furnace bottom construction Introduce furnace bottom alarm lines: The lower alarm line extends 25mm above the furnace bottom refractory material, using four lines extending spirally in four directions; the side alarm lines are connected to the furnace wall wire mesh; add dry vibrating material in layers (each layer ≤100kg), after leveling, use a degassing fork to insert into the furnace bottom for degassing, with an insertion depth ≤12mm, and use a circular tamping head to tamp it down, with each tamping time ≥10min, tamping and degassing are carried out simultaneously, and vibrate for 20min after tamping. After multiple layers of material addition, degassing and tamping, the final furnace bottom height is controlled at 180mm.

[0045] Step 5: Furnace wall construction After leveling the furnace bottom, place the graphite crucible in the furnace and calibrate it to be concentric with the coil (spacing error ≤ 5mm). The crucible opening should be flush with the coil. Add dry vibrating material in layers (each layer ≤ 100kg). After leveling, use a degassing fork to insert into the furnace wall to degas the material to a depth ≤ 18mm. Use a furnace tamping head to tamp the material, with each tamping session lasting 25 minutes. Tamping and degassing are carried out simultaneously. After multiple layers of material addition, degassing, and tamping, continue until the material reaches 90mm from the furnace opening. Step 6: Pour spout and sealing masonry Clean the spout of any remaining debris, lay a 50mm thick layer of refractory material with a temperature resistance greater than 1650℃, tamp it down with a small hammer, and then level it with a scraper; place the graphite chute (aligned front and back, with uniform spacing left and right), fill the gaps with refractory material with a temperature resistance greater than 1650℃ and tamp it down to shape it; seal the opening with refractory material with a temperature resistance greater than 1650℃: cut it into granules and fill the gaps at the furnace opening, tamp it down layer by layer until it is 100mm above the furnace opening, and shape it with a scraper; cut the mica paper that extends above the furnace opening, and the furnace construction is complete.

[0046] Step 7: Oven baking After 12 hours of air curing, the furnace was electrically heated. The heating rate was 48℃ / h. At 500℃, the furnace was held for 20 hours; at 800℃, it was held for 15 hours; and at 1100℃, it was held for 8 hours. Electrolytic copper was added to the furnace in batches, with 180kg of raw material added per batch until the furnace was full. After all the electrolytic copper had melted, the furnace was held for 0.4 hours. The molten alloy was then poured into the furnace and cast. The ingots were then subjected to end-face penetration testing. If defects such as porosity were found, the furnace heating process was repeated until the end-face penetration test of the ingots showed no defects. The furnace heating process was then complete. Subsequent verification showed that the furnace's service life increased from 80 heats to 140 heats; a furnace leakage alarm signal was detected.

[0047] Example 3 Step 1: Pre-furnace inspection Remove the refractory material from the furnace wall and clean the debris from the furnace bottom, then remove the graphite crucible; use a megohmmeter to test the insulation resistance of the induction coil, ensuring it is ≥6200Ω; if there is a local insulation abnormality that can be repaired, repair it and retest; if the coil is damaged or the insulation is irreparable, remove the inductor, repair it, and then reinstall it; check the cooling water flow rate to be 4-4.5m³ / h. 3 / h, confirm that the water-cooled cable and connecting pipe are sealed without leakage; check the tightness of the screws and the integrity of the solder joints of the bottom support frame and the coil fixing plate of the coil.

[0048] Step 2: Coil grout layer construction The mass ratio of refractory to water should be controlled at 8%. Water should be added first, and then the mortar should be prepared using a mixer. The mortar should be evenly applied to the induction coil turns and inner surface using a trowel, ensuring that the surface is concentric with the coil, with a thickness of 6±0.5mm. After new construction or major repairs, air curing should be carried out for at least 28 hours, and infrared lamps should be used for continuous heating and baking during the curing period. Step 3: Installation of furnace leakage protection and alarm devices Lay five 0.35mm thick 1500×1000mm mica sheets, flat against the inner wall of the coil; roll up an 800×2200mm non-magnetic stainless steel wire mesh (0.65mm diameter, 9×9mm mesh opening) and place it into the coil, then unfold it and place it against the mica sheets; install the furnace leakage alarm signal line and test it to be normal; lay three 2.0mm thick 1500×1000mm ceramic fiber cloths, flat against the stainless steel wire mesh; cut the protruding mica sheets and ceramic fiber cloth at intervals to be flush with the top edge of the coil, then extend them outwards, press them onto the top of the furnace body and fix them in place; Step 4: Furnace bottom construction Introduce furnace bottom alarm lines: The lower alarm line extends 30mm above the furnace bottom refractory material, using four lines extending spirally in four directions; the side alarm lines are connected to the furnace wall wire mesh; add dry vibrating material in layers (each layer ≤90kg), after leveling, use a degassing fork to insert into the furnace bottom for degassing, with an insertion depth ≤10mm, and use a circular tamping head to tamp it down, with each tamping time ≥12min, tamping and degassing are carried out simultaneously, and vibrate for 10min after tamping. After multiple layers of material addition, degassing and tamping, the final furnace bottom height is controlled at 200mm.

[0049] Step 5: Furnace wall construction After leveling the furnace bottom, place the graphite crucible in the furnace and calibrate it to be concentric with the coil (spacing error ≤ 5mm). The crucible opening should be flush with the coil. Add dry vibrating material in layers (each layer ≤ 80kg). After leveling, use a degassing fork to insert into the furnace wall to degas the material to a depth ≤ 16mm. Use a furnace tamping head to tamp the material, with each tamping session lasting 20 minutes. Tamping and degassing are carried out simultaneously. After multiple layers of material addition, degassing, and tamping, continue until the material reaches 100mm from the furnace opening. Step 6: Pour spout and sealing masonry Clean the spout of any remaining debris, lay a 60mm thick layer of refractory material with a temperature resistance greater than 1650℃, tamp it down with a small hammer, and then level it with a scraper; place the graphite chute (aligned front and back, with uniform spacing left and right), fill the gaps with refractory material with a temperature resistance greater than 1650℃ and tamp it down to shape it; seal the opening with refractory material with a temperature resistance greater than 1650℃: cut it into granules and fill the gaps at the furnace opening, tamp it down layer by layer until it is 100mm above the furnace opening, and shape it with a scraper; cut the mica paper that extends above the furnace opening, and the furnace construction is complete.

[0050] Step 7: Oven baking After 12 hours of air curing, the furnace was electrically heated. The heating rate was 52℃ / h. At 500℃, the furnace was held for 20 hours; at 800℃, it was held for 15 hours; and at 1100℃, it was held for 8 hours. Electrolytic copper was added to the furnace in batches, with 180kg of raw material added per batch until the furnace was full. After all the electrolytic copper had melted, the furnace was held for 0.6 hours. The molten alloy was then poured into the furnace and cast. The ingots were then subjected to end-face penetration testing. If defects such as porosity were found, the furnace heating process was repeated until the end-face penetration test of the ingots showed no defects. The furnace heating process was then complete. Subsequent verification showed that the furnace's service life increased from 80 heats to 150 heats; a furnace leakage alarm signal was detected.

[0051] In summary, the solution proposed in this invention has the following technical effects: This invention improves the concentricity of the mortar layer and coil by precisely constructing the coil slurry layer and standardizing curing with infrared lamp heating, thereby increasing the electromagnetic induction efficiency by more than 10%. It employs a multi-layered composite protective structure of mica paper, stainless steel wire mesh, and ceramic fiber cloth, combined with a furnace leakage alarm signal line, reducing the furnace leakage warning response time to less than 0.5 seconds and lowering the risk of furnace leakage by 90%. Strict control over the quantitative layering, degassing, and tamping time of the dry vibrating material at the furnace bottom and walls increases the furnace body's compressive strength by 20-30% and extends its service life from 80 to over 120 furnace cycles. The spout and sealing material use refractory materials with a temperature resistance greater than 1650℃ to shorten repair time by 55%.

[0052] Furthermore, the present invention combines a low-power baking oven method with a baking oven with material, which ensures the baking effect.

[0053] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for building a vacuum melting furnace for beryllium copper alloy, characterized by, The furnace building method comprises: Step S1, cleaning the furnace wall and the furnace bottom; Step S2, preparing a mortar with a mass content of 5-8% of the castable, uniformly applying the mortar to the inner surface of the induction coil of the furnace wall to form a mortar layer concentric with the induction coil, and then performing air curing; the air curing period satisfies: ≥28h for new construction or major repair, ≥8h for minor repair, and the infrared lamp is continuously heated and baked during the air curing period; Step S3, sequentially laying mica paper, stainless steel wire mesh, furnace leakage alarm signal line and ceramic fiber cloth in the induction coil after applying the mortar, cutting the protruding mica paper and ceramic fiber cloth to be flush with the upper edge of the induction coil and then extending outward, pressing and fixing them on the top of the furnace body; Step S4, placing the furnace leakage alarm signal line in the furnace bottom, and adding dry vibrating material in at least three layers to make the height of the furnace bottom 150-200mm; Wherein, the amount of each layer of material is ≤100kg, each layer needs to be leveled, degassed and tamped after leveling, and the tamping time of each time is ≥10min, and each tamping is vibrated for 10-20min; Step S5, placing a crucible in the induction coil obtained in step S3, and adding dry vibrating material in at least six layers to the position 80-100mm away from the furnace mouth; Wherein, the amount of each layer of material is ≤100kg, each layer needs to be leveled, degassed and tamped after leveling, and the tamping time of each time is ≥20min; Step S6, laying 50-60mm thick refractory material with a temperature resistance greater than 1650℃ at the pouring nozzle, placing a chute and filling refractory material with a temperature resistance greater than 1650℃, and using refractory material with a temperature resistance greater than 1650℃ to layer and seal to more than 100mm above the furnace mouth.

2. The beryllium-copper alloy vacuum melting furnace construction method according to claim 1, characterized by, In the step S1, the specific process of cleaning the furnace wall and the furnace bottom comprises: stripping the furnace wall refractory material and cleaning the furnace bottom.

3. The beryllium-copper alloy vacuum melting furnace construction method according to claim 1, characterized by, The furnace building method further comprises: before the step S2, controlling the cooling water path flow rate to be 3-4.5 m 3 / h and determining whether the insulation resistance of the detection induction coil is not less than 5500Ω. When the insulation resistance of the induction coil is less than 5500Ω, the induction coil is laser welded and repaired or replaced with a new induction coil.

4. The beryllium-copper alloy vacuum melting furnace construction method according to claim 1, characterized by In the step S2, the thickness of the mortar layer is 4-6mm, and the thickness error of each part is ±0.5mm.

5. The beryllium-copper alloy vacuum melting furnace construction method according to claim 1, characterized by In the step S3, the number of layers of the mica paper laid is 3-5 layers, and the thickness of each layer of mica paper is 0.35-0.45mm; The mesh opening of the stainless steel wire mesh is a square mesh opening with a side length of 7-9mm, and the diameter of a single stainless steel wire in the stainless steel wire mesh is 0.55-0.65mm; The number of layers of the ceramic fiber cloth laid is 3-5 layers, and the thickness of each layer of ceramic fiber cloth is 1.5-2mm.

6. The beryllium-copper alloy vacuum melting furnace construction method according to claim 5, characterized by In the step S3, the stainless steel wire mesh is laid close to the mica paper.

7. The beryllium-copper alloy vacuum melting furnace construction method according to claim 1, characterized by, In the step S4, the furnace leakage alarm signal line placed in the furnace bottom is 20-30mm higher than the refractory material of the furnace bottom; In the step S5, the crucible is a graphite crucible, the crucible is concentric with the induction coil, and the crucible mouth is flush with the upper edge of the induction coil; In the step S4 and step S5, degassing and tamping are performed synchronously, a degassing fork is inserted into the furnace bottom for degassing, and the insertion depth of the degassing fork is ≤20mm.

8. The beryllium-copper alloy vacuum melting furnace construction method according to claim 1, characterized by, In the step S6, the pouring nozzle is cleaned before laying the refractory material at the pouring nozzle; The chute is a graphite chute; After the sealing, the mica paper and ceramic fiber cloth above the opening are cut.

9. A beryllium copper alloy vacuum melting furnace built by the method of any one of claims 1-8.

10. A method of baking a vacuum melting furnace for beryllium copper alloy as claimed in claim 9, characterized in that, The furnace building method comprises: The built beryllium copper alloy vacuum melting furnace is air-cured for 8-12 hours, and then is electrically baked, with a heating rate of 48-52 ℃ / h; After the baking is completed, the furnace is baked with materials, each batch of raw materials is less than or equal to 200 kg, until the furnace is full, and after the materials are completely melted, the furnace is kept for 0.4-0.6 hours, and then the furnace is poured to obtain baked ingots; The baked ingots are repeatedly baked with materials until the end of the baked ingots, and the end face of the baked ingots is detected by penetration detection without defects.