Method for producing C18150 chromium zirconium copper through full continuous casting

Abstract

The invention relates to the technical field of chromium-zirconium-copper full continuous casting production, and provides a method for producing C18150 chromium-zirconium-copper through full continuous casting, which comprises the following steps of: 1, proportioning components of molten copper mixed by electrolytic copper and refractory alloy chromium in a melting furnace covered with charcoal, and transferring the molten copper into a heat preserving furnace through a siphon flow turning runner after the molten copper is qualified; secondly, the molten copper is covered with granular graphite in the heat preservation furnace; according to the method, a sealed space is formed through the fire-resistant partition wall, the pouring box cover and argon protection, external air is isolated from entering, the opportunity that extremely lively metal such as zirconium is combined with oxygen is eliminated, the effect similar to that of vacuum furnace smelting is achieved, oxidation and inclusions can be effectively reduced, the ingot casting quality is improved, and the production cost is reduced. In addition, the zirconium-copper alloy core-spun yarn is guided in through a wire feeder mechanism and alloyed with molten copper, the speed of a wire feeder is steplessly adjustable and matched with the casting speed, the purpose of component stabilization is achieved, alloy elements can be continuously and stably provided through the method, and the uniformity and stability of the components are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of chromium-zirconium-copper full-continuous casting production, and in particular to a method for producing C18150 chromium-zirconium-copper through full-continuous casting. Background Art

[0002] There are two common processes for producing C18150 chrome-zirconium-copper alloys. 1. Vacuum melting and casting. Melting zirconium-copper or chrome-zirconium-copper alloys in a vacuum environment prevents oxidation and burning of the zirconium, resulting in high-quality ingots. However, this process requires significant equipment investment, making it difficult to produce ingots weighing more than 5 tons, thus limiting production capacity. 2. Coreless melting involves melting in an argon-shielded launder with the regular addition of a zirconium-copper master alloy. This process, due to the intermittent addition of the copper alloy, results in periodic fluctuations in composition, numerous oxide inclusions in the ingots, and significant difficulty in controlling ingot quality.

[0003] After searching, document 1 was found. The announcement number is CN107586975B, which discloses a production method of copper-chromium-zirconium upward continuous casting. The advantages of this production process are: using an industrial frequency upward continuous casting furnace, adding pure chromium and pure zirconium, adopting argon protection measures and online continuous zirconium addition methods to reduce the burnout of chromium and zirconium, and improve the stability of zirconium content. The volatilization of chromium is less than 10%, and the volatilization of zirconium is less than 30%, thereby realizing continuous and large-scale production of copper-chromium-zirconium alloy.

[0004] A search revealed document 2, Publication No. CN119702980A, which discloses a non-vacuum upward continuous casting process for copper-chromium-zirconium alloy rods. The process involves adding electrolytic copper to a smelting furnace, adding a covering agent, intermittently filling the covering agent with nitrogen, heating it until molten, adding chromium raw material, and then adding a copper-zirconium master alloy. Prior to upward continuous casting, a graphite mold is mounted on the bottom of a water-cooled copper sleeve. Asbestos and graphite protective sleeves are installed on the mold exterior, which is then mounted on a traction frame. A pure copper guide is connected to the end of a stainless steel traction rod and placed in the crystallizer. After installation, the water cooling system is activated. For upward continuous casting, the crystallizer is lowered below the melt surface, the traction mechanism is activated, and casting of the copper-chromium-zirconium alloy rod begins according to preset traction parameters. Simultaneously, a servo motor is activated to automatically feed pure Cr and Zr wires into the copper melt. Advantages of this process include preventing surface roughening of the graphite mold due to surface reactions during the casting process, ensuring a bright surface quality for the cast rods, and ensuring a continuous and stable upward continuous casting process.

[0005] The present invention utilizes oxygen-free copper continuous melting and casting equipment to obtain copper liquid with an oxygen content of 10ppm. A closed space is formed in a pouring box, which is protected by argon gas. A wire feeder continuously supplies zirconium-copper cored wire to provide a metal liquid with stable composition and pure copper water, thereby obtaining a high-quality C18150 large ingot (5-10 tons). Summary of the Invention

[0006] This invention proposes a fully continuous casting method for producing C18150 chromium-zirconium-copper alloys, resolving existing zirconium-copper and chromium-zirconium-copper process issues. When a copper-zirconium master alloy is added to a furnace, zirconium is extremely reactive and susceptible to oxidation and burning. Producing high-quality, large ingots (over 5 tons) with stable composition and abundant oxidized slag inclusions is difficult under non-sealed or non-vacuum conditions. The present invention aims to create a closed environment to address the unstable composition and high inclusion content of zirconium or readily oxidizable copper alloys, enabling the production of C18150 chromium-zirconium-copper alloy or zirconium-copper alloy ingots using a fully continuous casting machine.

[0007] The technical solution of the present invention is as follows: A method for producing C18150 chromium-zirconium copper by full continuous casting, comprising the following steps: Step 1: Mix the electrolytic copper and refractory alloy chromium in a charcoal-covered melting furnace, and transfer the qualified copper liquid to a holding furnace through a siphon transfer chute; Step 2: The molten copper is covered by granular graphite in a holding furnace. A vent plug is placed at the bottom of the holding furnace, and a refining mixed gas of CO+N2 is passed through it for a long time. Step 3: The oxygen in the copper liquid reacts with the CO in the refined mixed gas to further remove oxygen, reducing the oxygen content to below 10 ppm; The slag in the copper liquid adheres to the tiny N2 bubbles and floats up with the bubbles into the slag; When hydrogen atoms in the copper liquid diffuse, they enter the N2 bubbles and form H2, which then floats to the surface of the copper liquid and is discharged from the copper liquid, achieving the purpose of hydrogen removal. Step 4: A refractory retaining wall is installed between the pouring box and the holding furnace body, and the copper liquid flows into the pouring box through the channel below the refractory retaining wall; Step 5: The refractory retaining wall and the lid of the pouring box form a closed space. Argon gas enters the pouring box through a flow meter, forming a protective gas layer composed of argon gas above the copper liquid to isolate external gases from entering the pouring box. The surface of the copper liquid is covered with phosphorus flake graphite to further isolate external harmful gases. Step 6: A copper-zirconium cored wire is made from an easily oxidizable alloy primarily composed of zirconium and copper. The wire is passed through a wire rack, a wire feeder, and a wire tube, passing through a phosphorus flake graphite layer and into the copper liquid. The copper-zirconium cored wire melts and diffuses, alloying the copper. The copper-zirconium cored wire, in conjunction with the casting speed, forms a continuous and stable alloying process. Step seven: After alloying, the molten copper passes through a pouring pipe and enters a continuous casting machine, and is then drawn into an ingot by the continuous casting machine.

[0008] Preferably, the covering thickness of the charcoal in the melting furnace in step 1 is 200 mm.

[0009] Preferably, the connection portion between the siphon diversion flow channel and the insulation furnace is sealed by a sealing ring.

[0010] Preferably, the covering thickness of the granular graphite in step 2 is 150 mm, and the mixing ratio of CO to N2 in the refined mixed gas is 1:4.

[0011] Preferably, the covering thickness of the flake graphite in step five is 50 mm.

[0012] Preferably, the diameter of the copper-zirconium cored wire in step six is 6-20 mm.

[0013] The beneficial effects of the present invention are: 1. The present invention forms a sealed space through refractory partitions, a pouring box cover, and argon gas protection, isolating the ingress of external air and eliminating the opportunity for extremely reactive metals such as zirconium to combine with oxygen, thereby achieving similar results to vacuum furnace smelting. This method can effectively reduce oxidation and the generation of inclusions, thereby improving the quality of the ingot. Although Documents 1 and 2 also use inert gas (nitrogen and argon) protection, they primarily prevent oxidation through covering agents and gas protection, and do not form a completely closed environment. 2. The present invention introduces zirconium-copper alloy cored wire through a wire feeder mechanism for alloying with molten copper. The wire feeder speed is steplessly adjustable to match the casting speed, achieving composition stability. This method can continuously and stably provide alloying elements, ensuring the uniformity and stability of the composition. Although the prior art also uses a method of adding chromium and zirconium online, document 1 uses automatic wire feeding by a servo motor, and document 2 uses online addition of pure zirconium wire, which cannot achieve the same precision and stability as the wire feeder introduction system of the present invention. 3. In the present invention, a vent plug is provided at the bottom of the furnace, and a mixed refining gas of CO and N2 is introduced to refine the copper liquid to obtain high-quality copper liquid with low oxygen and low hydrogen. The oxygen is further removed by the reaction of CO with oxygen in the copper liquid to reduce the oxygen content to below 10 ppm. At the same time, slag inclusions and hydrogen atoms are taken away by N2 bubbles to achieve the purpose of hydrogen removal. This method can effectively improve the purity of the copper liquid and reduce the inclusion and hydrogen content. Although Documents 1 and 2 also use covering agents and gas protection to prevent oxidation, they do not explicitly mention the process of deoxidation and dehydrogenation by refining mixed gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is the equipment layout diagram for producing C18150 chromium-zirconium-copper by full continuous casting proposed in the present invention; Figure 2 This is a schematic structural diagram of the holding furnace proposed in the present invention; Figure 3 for Figure 2 A in the middle is an enlarged schematic diagram; Figure 4 for Figure 2The enlarged schematic diagram of point B in the middle; In the figure: 1. Holding furnace; 2. Melting furnace; 3. Siphon flow chute; 4. Sealing ring; 5. Wire rack; 6. Wire feeder; 7. Wire tube; 8. Phosphorus flake graphite; 9. Refractory retaining wall; 10. Fully continuous casting machine; 11. Breathing plug; 12. Refined mixed gas; 13. Granular graphite; 14. Argon; 15. Flow meter; 16. Copper-zirconium cored wire; 17. Casting box. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1-Figure 4 The present invention provides a technical solution: a method for producing C18150 chromium-zirconium copper by full continuous casting, comprising the following steps: Step 1: Electrolytic copper and refractory alloy chromium are mixed in a charcoal-covered melting furnace 2. Once the components meet the requirements, the mixture is transferred to the holding furnace 1 via a siphon flow chute 3. The charcoal covering is 200 mm thick. The connection between the siphon flow chute 3 and the holding furnace 1 is sealed by a sealing ring 4. Step 2: The molten copper is covered with granular graphite 13 in the holding furnace 1 to a thickness of 150 mm. A vent plug 11 is placed at the bottom of the holding furnace 1, and a refined mixed gas 12 of CO+N2 is passed through the furnace for a long period of time. The mixing ratio of CO to N2 in the refined mixed gas 12 is 1:4. Step 3: The oxygen in the copper liquid reacts with the CO in the refined mixed gas 12 to further remove oxygen, reducing the oxygen content to below 10 ppm; The slag in the copper liquid adheres to the tiny N2 bubbles and floats up with the bubbles into the slag; When hydrogen atoms in the copper liquid diffuse, they enter the N2 bubbles and form H2, which then floats to the surface of the copper liquid and is discharged from the copper liquid, achieving the purpose of hydrogen removal. Step 4: A refractory retaining wall 9 is installed between the pouring box 17 and the holding furnace 1, and the copper liquid flows into the pouring box 17 through the lower channel of the refractory retaining wall 9; Step 5: The refractory retaining wall 9 and the cover of the pouring box 17 form a closed space. Argon gas 14 enters the pouring box 17 through the flow meter 15, forming a protective gas layer composed of argon gas 14 above the copper liquid to isolate external gases from entering the pouring box 17. The surface of the copper liquid is covered with phosphorus flake graphite 8, and the covering thickness of the phosphorus flake graphite 8 is 50 mm, which further isolates external harmful gases. Step 6: A copper-zirconium cored wire 16 is made of an easily oxidizable alloy primarily composed of zirconium and copper. The copper-zirconium cored wire 16 has a diameter of 6-20 mm and is passed through a wire rack 5, a wire feeder 6, a wire tube 7, and a layer of phosphorus flake graphite 8 into the molten copper. The copper-zirconium cored wire 16 melts and diffuses to alloy the copper. The copper-zirconium cored wire 16 is coordinated with the casting speed to form a continuous and stable alloying process. Step seven: After alloying, the molten copper passes through the pouring pipe and enters the continuous casting machine 10, and is then drawn and cast into an ingot by the continuous casting machine 10.

[0018] The present invention uses a fully continuous casting machine to produce C18150 chromium-zirconium-copper alloy ingots, while Documents 1 and 2 primarily employ an upward continuous casting process. The fully continuous casting process enables large-scale, continuous production and is suitable for producing large ingots (5-10 tons), while the upward continuous casting process of Documents 1 and 2 is more suitable for producing smaller diameter rods (8-30 mm). In summary, the technical solution of the present invention achieves large-scale, high-quality, and compositionally stable production of C18150 chromium-zirconium-copper alloy ingots through a fully continuous casting process, a closed environment and argon protection, alloying by a wire feeder, and deoxidation and hydrogen removal of the refined mixed gas, offering significant innovative advantages.

[0019] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for producing C18150 chromium-zirconium copper by continuous casting, characterized in that: The following steps are involved: Step 1: Mix the electrolytic copper and the refractory alloy chromium in a charcoal-covered melting furnace (2) and transfer the copper solution to the holding furnace (1) through a siphon transfer chute (3) after the components are qualified. Step 2: The molten copper is covered by granular graphite (13) in the holding furnace (1), a vent plug (11) is placed at the bottom of the holding furnace (1), and a refined mixed gas (12) consisting of CO+N2 is passed through the furnace for a long period of time; Step 3: The oxygen in the copper liquid reacts with the CO in the refining mixed gas (12) to further remove oxygen, reducing the oxygen content to below 10 ppm; The slag in the copper liquid adheres to the tiny N2 bubbles and floats up with the bubbles into the slag; When hydrogen atoms in the copper liquid diffuse, they enter the N2 bubbles and form H2, which then floats to the surface of the copper liquid and is discharged from the copper liquid, achieving the purpose of hydrogen removal. Step 4: A refractory retaining wall (9) is installed in the pouring box (17) and the holding furnace (1), and the copper liquid flows into the pouring box (17) through the lower channel of the refractory retaining wall (9); Step 5: The fireproof retaining wall (9) and the cover of the pouring box (17) form a closed space, and the argon gas (14) enters the interior of the pouring box (17) through the flow meter (15), forming a protective gas layer composed of the argon gas (14) above the copper liquid to isolate the external gas from entering the pouring box (17). The surface of the copper liquid is covered with phosphorus flake graphite (8), which further isolates the external harmful gas; Step 6: A copper-zirconium cored wire (16) is made of an easily oxidizable alloy with zirconium and copper as main components, and is passed through a wire rack (5), a wire feeder (6), a wire tube (7), and a phosphorus flake graphite (8) layer into the copper liquid. The copper-zirconium cored wire (16) melts and diffuses to alloy the copper, and the copper-zirconium cored wire (16) cooperates with the casting speed to form a continuous and stable alloying process. In step seven, the alloyed copper liquid passes through a pouring pipe and enters a fully continuous casting machine (10), and is then drawn and cast into an ingot by the fully continuous casting machine (10).

2. The method for producing C18150 chromium-zirconium copper by continuous casting according to claim 1, characterized in that: The charcoal covering thickness of the melting furnace (2) in step 1 is 200 mm.

3. The method for producing C18150 chromium-zirconium copper by full continuous casting according to claim 1, characterized in that: The connection point between the siphon transfer flow channel (3) and the insulation furnace (1) is sealed by a sealing ring (4).

4. The method for producing C18150 chromium-zirconium copper by full continuous casting according to claim 1, characterized in that: The covering thickness of the granular graphite (13) in the step 2 is 150 mm, and the mixing ratio of CO to N2 in the refined mixed gas (12) is 1:

4.

5. The method for producing C18150 chromium-zirconium copper by full continuous casting according to claim 1, characterized in that: The covering thickness of the phosphorus flake graphite (8) in step 5 is 50 mm.

6. The method for producing C18150 chromium-zirconium copper by full continuous casting according to claim 1, characterized in that: The diameter of the copper-zirconium cored wire (16) in step six is 6-20 mm.

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