A method and system for producing a copper alloy ingot that eliminates gas bubbles
By employing techniques such as raw material pretreatment, two-stage heat preservation, and directional solidification cooling for copper alloy ingots, the problem of bubble defects in copper alloy ingots has been solved, achieving efficient gas removal and improved product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN JIN XI CHUNLEI COPPER CO LTD
- Filing Date
- 2026-04-17
- Publication Date
- 2026-06-12
AI Technical Summary
Existing copper alloy ingots have a high rate of bubble defects during smelting and casting, which affects product quality and performance. The existing process has failed to effectively form a closed-loop control throughout the entire process.
Through multi-stage coordinated control, including raw material pretreatment, two-stage heat preservation and gas discharge during the casting stage, technologies such as drying and degreasing, heat preservation in micro-oxidizing and reducing atmospheres, and directional solidification and cooling are adopted to achieve coordinated removal and directional discharge of gases.
It significantly reduces the bubble rate in copper alloy ingots to 0.01%, improves the product qualification rate to over 99%, and avoids delamination and peeling defects in subsequent processing.
Smart Images
Figure CN122189367A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of copper alloy casting technology, specifically to a method and system for preparing copper alloy ingots that eliminates casting bubbles. Background Technology
[0002] Copper alloys are widely used in electronics, machinery, aerospace, and other fields due to their excellent electrical, thermal, and mechanical properties. In the production process of copper alloy strip, the quality of the ingot directly determines the performance of the final product, with bubble defects being a key factor affecting product yield. In existing technologies, during the smelting and casting process of copper alloy ingots, moisture and grease carried by the raw materials will burn and decompose at high temperatures, producing gases such as water vapor, hydrogen, and carbon monoxide. Some of these gases dissolve in the molten copper, and if not promptly removed, they will form bubbles inside the ingot. Such bubble-containing ingots are highly susceptible to causing significant quality problems such as delamination and peeling during subsequent strip processing such as rolling and forging, severely affecting product dimensional accuracy and performance, posing a significant risk to downstream customers, and causing substantial economic losses.
[0003] Currently, the industry's methods for controlling bubble defects in copper alloy ingots are relatively limited, often relying solely on single gas protection or simple deoxidation processes. This fails to establish a closed-loop control system encompassing the entire process from raw material pretreatment to casting venting. For example, some processes focus only on deoxidation during the smelting stage, neglecting the impact of temperature distribution within the crystallizer on gas rise during casting; or, although directional solidification technology is employed, the cooling parameters and venting structure are not properly matched, resulting in insufficient gas removal and persistently high bubble rates in the ingots. Therefore, developing an integrated process that combines smelting degassing, heat preservation deoxidation, and casting venting has become an urgent need to address bubble defects in copper alloy ingots. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a method and system for preparing copper alloy ingots that eliminates casting bubbles. Through multi-stage coordinated control, it reduces gas generation at the source, strengthens deoxidation and degassing in the intermediate process, and optimizes exhaust conditions during the casting stage, thereby significantly reducing the bubble content of copper alloy ingots and ensuring the quality of subsequent strip processing.
[0005] This invention discloses a method for preparing copper alloy ingots to eliminate casting bubbles, comprising: Step 1: Perform drying and degreasing pretreatment on the copper alloy raw materials to reduce gas generation from the source; Step 2: Melt the pretreated raw materials to obtain molten copper. Selectively perform two-stage heat preservation based on the reducing gas content in the molten copper: When the reducing gas content in the molten copper is greater than the first preset threshold, perform the first stage of heat preservation in a slightly oxidizing atmosphere and the second stage of heat preservation in a reducing atmosphere in sequence; when the reducing gas content in the molten copper is not greater than the first preset threshold, directly perform the second stage of heat preservation in a reducing atmosphere to achieve degassing and deoxidation of the molten copper. Step 3: Perform low-temperature casting on the deoxidized and degassed copper, and control the embedding depth, carbon black coverage, copper liquid surface state and directional solidification cooling during the casting process to achieve directional discharge of air bubbles.
[0006] As a further improvement of the present invention, in step 1, the water content in the pretreated copper alloy raw material is ≤0.1%, and the oil content is ≤0.05%.
[0007] As a further improvement of the present invention, in step 2, the first stage of micro-oxidizing atmosphere heat preservation is as follows: nitrogen gas is introduced into the heat preservation furnace at a flow rate of 5-10 Nm³ / h, the oxygen content in the furnace is controlled at 18-21%, and the heat preservation is carried out for 15-25 min to remove reducing gases from the copper water. The second stage of reducing atmosphere heat preservation is as follows: nitrogen gas is introduced into the heat preservation furnace at a flow rate of 15-25 Nm³ / h, the oxygen content in the furnace is controlled at 14-16%, and the heat preservation is carried out for 20-30 minutes to remove oxygen from the copper water. After heat preservation treatment, the oxygen content in the copper solution is ≤0.003%, and the total content of reducing gases is ≤0.001%.
[0008] As a further improvement of the present invention, the heat preservation temperature in both stages is 30-80°C higher than the liquidus temperature of the copper alloy.
[0009] As a further improvement of the present invention, the first preset threshold is 0.001%.
[0010] As a further improvement of the present invention, step 3 specifically includes: Molten copper flows through a buried pipe into a tee pipe and then into a crystallizer. The upper edge of the buried pipe just covers the upper edge of the tee pipe. A carbon black layer is placed on the surface of the molten copper in the crystallizer to control the liquid level and directional solidification cooling is used to allow bubbles to be discharged directionally through the carbon black layer.
[0011] As a further improvement of the present invention, the height difference between the upper edge of the buried pipe and the tee pipe is 1-3.5mm; The carbon black layer has a particle size of 26±3nm and a coverage thickness of 1-3mm. It is replenished frequently in small amounts, with a replenishment cycle of 2-3 minutes.
[0012] As a further improvement of the present invention, the fluctuation range of the copper liquid level in the crystallizer is ≤ ±0.5mm, and the liquid level is 5-10mm away from the upper edge of the crystallizer.
[0013] As a further improvement of the present invention, the low-temperature casting temperature is 30-50°C higher than the liquidus temperature of the copper alloy; the directional solidification cooling water enters from the lower edge of the crystallizer and exits from the upper edge, with an inlet temperature of 15-25°C and an outlet temperature of 40-55°C.
[0014] This invention discloses a copper alloy ingot preparation system for eliminating casting bubbles, which is applied to the aforementioned copper alloy ingot preparation method for eliminating casting bubbles, characterized in that it includes: Pretreatment equipment is used for drying and degreasing copper alloy raw materials; A smelting furnace is used to melt pretreated copper alloy raw materials into molten copper. The heat preservation furnace is equipped with a nitrogen supply system and an oxygen content detection and control system, which are used to selectively perform heat preservation in a micro-oxidizing atmosphere or a reducing atmosphere according to the reducing gas content in the copper liquid. A casting apparatus includes a tee pipe, a submerged pipe, a crystallizer, and a directional solidification cooling system; the submerged pipe is configured to cooperate with the tee pipe; the crystallizer is used to receive molten copper from the tee pipe, and the surface of the molten copper in the crystallizer is covered with a layer of carbon black; the directional solidification cooling system is used to form a temperature gradient from top to bottom and from center to edge in the crystallizer to achieve directional discharge of bubbles.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention precisely controls the moisture and oil content through raw material pretreatment, reducing gas generation at the source and solving the gas source problem caused by raw material impurities in traditional processes. At the same time, it innovatively adopts a two-stage heat preservation process of "micro-oxidizing atmosphere + reducing atmosphere", first removing reducing gases and then strengthening deoxidation, achieving synergistic removal of oxygen and reducing gases. Compared with single atmosphere treatment, the gas content in copper water is reduced by more than 60%.
[0016] This invention utilizes multi-parameter collaborative optimization during the casting stage to precisely match the buried tube depth, carbon black coverage thickness, and liquid level height, providing a smooth channel for gas discharge. Predictive flow rate control avoids gas entrainment caused by liquid level fluctuations. The directional solidification technology and reasonable temperature gradient design take advantage of the natural law that gas moves towards high-temperature areas with good fluidity and low resistance. Furthermore, the solubility of gas in molten copper decreases with decreasing temperature, promoting efficient bubble rising and directional precipitation, thereby effectively removing bubbles and significantly reducing the probability of residual bubbles inside the ingot.
[0017] This invention is based on low-temperature casting and utilizes the characteristic that the solubility of gas in molten copper decreases as the temperature decreases to further reduce the gas carrying capacity of molten copper, so that the bubble rate of the ingot is ≤0.01%, which effectively avoids delamination and peeling defects in the subsequent strip processing and increases the product qualification rate to over 99%. Attached Figure Description
[0018] Figure 1 This is a flowchart of a method for preparing copper alloy ingots to eliminate casting bubbles, as disclosed in one embodiment of the present invention. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.
[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0021] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0022] The present invention will now be described in further detail with reference to the accompanying drawings: like Figure 1 As shown, a method for preparing copper alloy ingots to eliminate casting bubbles according to the present invention includes: Step 1: Raw material pretreatment The copper alloy raw materials are dried and degreased to reduce gas generation at the source. The water content of the pretreated copper alloy raw materials is ≤0.1% and the oil content is ≤0.05%, so as to reduce the generation and entry of gases such as water vapor, hydrogen, and carbon monoxide during the smelting process.
[0023] Step 2: Melting and Static Heating The pretreated raw materials are melted to obtain molten copper. Two-stage heat preservation is selectively performed according to the reducing gas content in the molten copper: when the reducing gas content in the molten copper is greater than a first preset threshold, the first stage of heat preservation in a slightly oxidizing atmosphere and the second stage of heat preservation in a reducing atmosphere are performed in sequence; when the reducing gas content in the molten copper is not greater than the first preset threshold, the second stage of heat preservation in a reducing atmosphere is performed directly to achieve degassing and deoxidation of the molten copper; in this invention, the first preset threshold is 0.001%.
[0024] In step 2, the first stage of micro-oxidizing atmosphere heat preservation is as follows: nitrogen gas is introduced into the heat preservation furnace at a flow rate of 5-10 Nm³ / h to form a micro-oxidizing atmosphere, the oxygen content in the furnace is controlled at 18-21%, and the heat preservation is carried out for 15-25 minutes to remove reducing gases such as hydrogen and carbon monoxide from the copper water, while promoting the thorough burning of the newly added charcoal and ensuring the diffusion deoxidation effect. The second stage of reducing atmosphere heat preservation involves introducing nitrogen gas into the heat preservation furnace at a flow rate of 15-25 Nm³ / h to create a reducing atmosphere, controlling the oxygen content in the furnace to 14-16%, and continuing the heat preservation for 20-30 minutes to remove oxygen from the copper solution, so that the oxygen content in the copper solution is ≤0.003% and the total content of reducing gas is ≤0.001%.
[0025] In step 2, the holding temperature in both stages is 30-80℃ higher than the liquidus temperature of the copper alloy.
[0026] Step 3: Low-Temperature Casting and Exhaust Control The deoxidized and degassed molten copper is subjected to low-temperature casting, and the casting process involves controlling the embedding depth, carbon black coverage, molten copper surface state, and directional solidification cooling parameters to achieve directional bubble removal. Specifically, this includes: Molten copper flows through a buried pipe into a tee pipe and then into the crystallizer. The upper edge of the buried pipe just covers the upper edge of the tee pipe. A carbon black layer is placed on the surface of the molten copper in the crystallizer to control the liquid level and directional solidification cooling is used to allow bubbles to be discharged directionally through the carbon black layer.
[0027] In step 3, the depth of the embedded pipe is checked by visual monitoring so that the embedded pipe for casting is just above the upper edge of the tee pipe. The height difference between the embedded pipe and the upper edge of the tee pipe is 1-3.5mm. When the height difference exceeds the range, the copper liquid flow rate is adjusted back by using a fine-tuning stopper rod.
[0028] In step 3, the carbon black layer is metallurgical carbon black with a particle size of 26±3nm and a coverage thickness of 1-3mm, just enough to completely cover the surface of the molten copper. It is replenished frequently in small amounts to avoid excessive thickness that could obstruct gas escape, with a replenishment cycle of 2-3 minutes. Specifically, the carbon black needs to be added according to the actual burn-off situation. When the carbon black in the crystallizer appears bright red, locally white, or the molten copper is exposed, it should be replenished promptly. The higher the furnace temperature, the faster the carbon black burn-off rate, and the more frequently it needs to be added. The amount of carbon black added at one time is related to the size of the crystallizer; regardless of the amount added at one time, the thickness of the added layer is used as the control standard.
[0029] In step 3, the flow rate of molten copper is controlled by a predictive fine-tuning method, and the liquid level of the crystallizer is monitored in real time. When there are signs of fluctuations exceeding ±1mm, the flow rate is immediately adjusted to control the fluctuation range of the molten copper in the crystallizer within ±0.5mm. The fluctuation range of the molten copper is observed by visually observing the scale markings on the upper edge of the crystallizer.
[0030] In step 3, when the copper molten liquid level is less than 5mm from the top edge of the crystallizer, it increases the risk of copper molten liquid fluctuation and overflow. Furthermore, since there is no internal circulating cooling water channel near the top edge of the crystallizer, and the copper temperature is higher near the T-junction, the upper edge of the crystallizer's inner wall is easily eroded by the high-temperature copper molten liquid when in prolonged contact (because the crystallizer is made of copper alloy), affecting its service life. Conversely, if the copper molten liquid level is greater than 10mm from the top edge of the crystallizer, it is insufficient to meet the maximum liquid capacity requirement. Therefore, the distance between the copper molten liquid level and the top edge of the crystallizer is set to 5-10mm to ensure the maximum liquid capacity within the crystallizer and improve the copper molten liquid replenishment and venting tolerance. In step 3, directional solidification is used to cool the molten copper in the crystallizer. The cooling water enters from the copper outlet at the lower edge of the crystallizer, flows through the internal circulation channel in the crystallizer wall to the upper edge, and then exits. Since the inlet cooling water in this invention is readily available room-temperature tap water, the water temperature is controlled below 55°C to ensure a larger specific heat capacity, which is more conducive to cooling the molten copper. Furthermore, given that the diameter of the internal circulation cooling channel in the crystallizer is fixed, the outlet water temperature can be controlled by controlling the water pressure to ensure cooling intensity and refine the crystal grains. However, if the outlet temperature is low, below 40°C, the cooling intensity will be too high, and sufficient time for bubbles to escape will not be guaranteed. Therefore, the inlet temperature of the cooling water is set to 15-25°C, and the outlet temperature is set to 40-55°C, creating a temperature gradient in the molten copper within the crystallizer that decreases progressively from top to bottom and from the center to the edge (with a gradient of 0.25°C / mm along the height of the crystallizer and from the edge to the center). The principle behind this phenomenon is as follows: As the temperature of the molten copper in the crystallizer decreases from top to bottom and from center to edge, the lower the temperature, the worse the fluidity of the molten copper. The greater the resistance to the movement of bubbles in the molten copper, the more the bubbles are driven to positions with better fluidity and less resistance. Moreover, the lower the temperature of the molten copper, the lower the solubility of the gas. After precipitating from the low-temperature position, the gas is discharged to the high-temperature region with higher solubility. Finally, from the edge to the center and from the bottom to the top, the bubbles move sequentially towards the center and the upper edge of the crystallizer and are discharged through the carbon black layer.
[0031] A copper alloy ingot preparation system for eliminating casting bubbles according to the present invention, applied to the above-mentioned method for preparing copper alloy ingots for eliminating casting bubbles, includes: Pretreatment equipment is used for drying and degreasing copper alloy raw materials; A smelting furnace is used to melt pretreated copper alloy raw materials into molten copper. The heat preservation furnace is equipped with a nitrogen supply system and an oxygen content detection and control system, which are used to selectively perform heat preservation in a micro-oxidizing atmosphere or a reducing atmosphere according to the reducing gas content in the copper liquid. The casting apparatus includes a tee pipe, a submerged pipe, a crystallizer, and a directional solidification cooling system; the submerged pipe and the tee pipe are configured together; the crystallizer is used to receive molten copper from the tee pipe, and the surface of the molten copper in the crystallizer is covered with a layer of carbon black; the directional solidification cooling system is used to form a temperature gradient from top to bottom and from the center to the edge in the crystallizer to achieve directional discharge of bubbles. Example 1
[0032] This Example 1 is based on the preparation of a brass ingot with eliminated casting bubbles. The specific steps are as follows: Step 1: Select Cu-Zn alloy raw materials, dry them at 120℃ for 4 hours using hot air drying, then clean and degrease them with ethanol solution using ultrasound. After drying, the water content of the raw materials is measured to be 0.08% and the oil content to be 0.03%. Step 2: Put the raw materials into a medium-frequency induction furnace and heat them to 1080℃ to melt them, obtaining molten brass; transfer the molten brass to a holding furnace for two-stage holding. Step 2.1, First stage: Introduce nitrogen gas at a flow rate of 8 Nm³ / h and maintain the temperature for 20 min under a slightly oxidizing atmosphere; Step 2.2, Second Stage: Increase the nitrogen flow rate to 20 Nm³ / h, maintain the temperature under a reducing atmosphere for 25 min, and then measure the oxygen content in the copper solution to be 0.002% and the total reducing gas content to be 0.0008%. Step 3: Low-temperature casting is adopted, with a casting temperature of 1090℃ (the liquidus temperature of brass is 1060℃). The casting process controls casting parameters, including: 1) The buried pipe just covers the upper edge of the tee pipe, with a height difference of 1mm; 2) The carbon black coverage thickness is 2mm, and it should be replenished every 2 minutes. If there are any signs of exposed copper, it should be replenished in time to keep the liquid surface completely covered. 3) Monitor the liquid level in the crystallizer in real time. When the fluctuation reaches 0.8mm, fine-tune the flow rate. Finally, control the liquid level fluctuation within ±0.4mm. 4) The liquid level inside the crystallizer is 8mm from the top edge; 5) Control the inlet temperature of the cooling water to 20℃ and the outlet temperature to 50℃ to achieve directional solidification, and the bubbles are discharged through the carbon black layer.
[0033] Based on the preparation method of Example 1, the prepared brass ingot was tested by non-destructive testing and the bubble rate was 0.008%. The subsequent rolling into 1.2mm thick strip did not show any delamination or peeling. The product qualification rate was 99.2%. Example 2
[0034] This embodiment 2 is based on the preparation of bronze ingots with eliminated casting bubbles. The specific steps are as follows: Step 1: Select Cu-Sn alloy raw materials, dry them at 110℃ for 5 hours, clean them with an alkaline degreasing agent using ultrasound, and then dry them again. The water content of the raw materials is 0.06% and the oil content is 0.02%. Step 2: The raw materials are melted at 1120℃ and then transferred to a holding furnace: Step 2.1, First stage: Introduce nitrogen gas at a flow rate of 7 Nm³ / h and maintain the temperature in a slightly oxidizing atmosphere for 22 min; Step 2.2, Second Stage: Increase the nitrogen flow rate to 22 Nm³ / h, maintain the reducing atmosphere for 28 min, and at this time, the oxygen content in the copper solution is 0.0015%, and the total content of reducing gases is 0.0006%. Step 3: Low-temperature casting is adopted, with a casting temperature of 1150℃ (the liquidus temperature of bronze is 1120℃). The casting process controls casting parameters, including: 1) The buried pipe just covers the top edge of the tee pipe, with a height difference of 0.5mm; 2) The carbon black coating thickness is 1.5mm; apply small amounts frequently. 3) Monitor the liquid level in the crystallizer in real time, and control the liquid level fluctuation within ±0.3mm; 4) The liquid level is 6mm from the top edge of the crystallizer; 5) Control the cooling water inlet temperature to 18℃ and the outlet temperature to 45℃.
[0035] Based on the preparation method of this embodiment 2, the prepared bronze ingot has a bubble rate of 0.006%, no delamination defects after subsequent forging and pressing, and the product qualification rate reaches 99.5%.
[0036] Advantages of this invention: This invention precisely controls the moisture and oil content through raw material pretreatment, reducing gas generation at the source and solving the gas source problem caused by raw material impurities in traditional processes. At the same time, it innovatively adopts a two-stage heat preservation process of "micro-oxidizing atmosphere + reducing atmosphere", first removing reducing gases and then strengthening deoxidation, achieving synergistic removal of oxygen and reducing gases. Compared with single atmosphere treatment, the gas content in copper water is reduced by more than 60%.
[0037] This invention utilizes multi-parameter collaborative optimization during the casting stage to precisely match the buried tube depth, carbon black coverage thickness, and liquid level height, providing a smooth channel for gas discharge. Predictive flow rate control avoids gas entrainment caused by liquid level fluctuations. The directional solidification technology and reasonable temperature gradient design take advantage of the natural law that gas moves towards high-temperature areas with good fluidity and low resistance. Furthermore, the solubility of gas in molten copper decreases with decreasing temperature, promoting efficient bubble rising and directional precipitation, thereby effectively removing bubbles and significantly reducing the probability of residual bubbles inside the ingot.
[0038] This invention is based on low-temperature casting and utilizes the characteristic that the solubility of gas in molten copper decreases as the temperature decreases to further reduce the gas carrying capacity of molten copper, so that the bubble rate of the ingot is ≤0.01%, which effectively avoids delamination and peeling defects in the subsequent strip processing and increases the product qualification rate to over 99%.
[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing copper alloy ingots to eliminate casting bubbles, characterized in that, include: Step 1: Perform drying and degreasing pretreatment on the copper alloy raw materials to reduce gas generation from the source; Step 2: Melt the pretreated raw materials to obtain molten copper. Selectively perform two-stage heat preservation based on the reducing gas content in the molten copper: When the reducing gas content in the molten copper is greater than the first preset threshold, perform the first stage of heat preservation in a slightly oxidizing atmosphere and the second stage of heat preservation in a reducing atmosphere in sequence; when the reducing gas content in the molten copper is not greater than the first preset threshold, directly perform the second stage of heat preservation in a reducing atmosphere to achieve degassing and deoxidation of the molten copper. Step 3: Perform low-temperature casting on the deoxidized and degassed copper, and control the embedding depth, carbon black coverage, copper liquid surface state and directional solidification cooling during the casting process to achieve directional discharge of air bubbles.
2. The method for preparing copper alloy ingots according to claim 1, characterized in that, In step 1, the water content in the pretreated copper alloy raw material is ≤0.1%, and the oil content is ≤0.05%.
3. The method for preparing copper alloy ingots according to claim 1, characterized in that, In step 2, the first stage of micro-oxidizing atmosphere heat preservation is as follows: nitrogen gas is introduced into the heat preservation furnace at a flow rate of 5-10 Nm³ / h, the oxygen content in the furnace is controlled at 18-21%, and the heat preservation is carried out for 15-25 min to remove reducing gases from the copper water. The second stage of reducing atmosphere heat preservation is as follows: nitrogen gas is introduced into the heat preservation furnace at a flow rate of 15-25 Nm³ / h, the oxygen content in the furnace is controlled at 14-16%, and the heat preservation is carried out for 20-30 minutes to remove oxygen from the copper water. After heat preservation treatment, the oxygen content in the copper solution is ≤0.003%, and the total content of reducing gases is ≤0.001%.
4. The method for preparing copper alloy ingots according to claim 1 or 3, characterized in that, The heat preservation temperature in both stages is 30-80℃ higher than the liquidus temperature of copper alloy.
5. The method for preparing copper alloy ingots according to claim 1, characterized in that, The first preset threshold is 0.001%.
6. The method for preparing copper alloy ingots according to claim 1, characterized in that, Step 3 specifically includes: Molten copper flows through a buried pipe into a tee pipe and then into a crystallizer. The upper edge of the buried pipe just covers the upper edge of the tee pipe. A carbon black layer is placed on the surface of the molten copper in the crystallizer to control the liquid level and directional solidification cooling is used to allow bubbles to be discharged directionally through the carbon black layer.
7. The method for preparing copper alloy ingots according to claim 6, characterized in that, The height difference between the upper edge of the buried pipe and the tee pipe is 1-3.5mm; The carbon black layer has a particle size of 26±3nm and a coverage thickness of 1-3mm. It is replenished frequently in small amounts, with a replenishment cycle of 2-3 minutes.
8. The method for preparing copper alloy ingots according to claim 6, characterized in that, The fluctuation range of the copper liquid level in the crystallizer is ≤ ±0.5mm, and the liquid level is 5-10mm away from the upper edge of the crystallizer.
9. The method for preparing copper alloy ingots according to claim 6, characterized in that, The low-temperature casting temperature is 30-50℃ higher than the liquidus temperature of copper alloys; the directional solidification cooling water enters from the lower edge of the crystallizer and exits from the upper edge, with an inlet temperature of 15-25℃ and an outlet temperature of 40-55℃.
10. A copper alloy ingot preparation system for eliminating casting bubbles, applied to the copper alloy ingot preparation method for eliminating casting bubbles according to any one of claims 1-9, characterized in that, include: Pretreatment equipment is used for drying and degreasing copper alloy raw materials; A smelting furnace is used to melt pretreated copper alloy raw materials into molten copper. The heat preservation furnace is equipped with a nitrogen supply system and an oxygen content detection and control system, which are used to selectively perform heat preservation in a micro-oxidizing atmosphere or a reducing atmosphere according to the reducing gas content in the copper liquid. A casting apparatus includes a tee pipe, a submerged pipe, a crystallizer, and a directional solidification cooling system; the submerged pipe is configured to cooperate with the tee pipe; the crystallizer is used to receive molten copper from the tee pipe, and the surface of the molten copper in the crystallizer is covered with a layer of carbon black; the directional solidification cooling system is used to form a temperature gradient from top to bottom and from center to edge in the crystallizer to achieve directional discharge of bubbles.