Preparation method of copper-zirconium intermediate alloy

Abstract

The invention belongs to the technical field of copper intermediate alloys, and relates to a preparation method of a copper-zirconium intermediate alloy, which comprises the following steps: sponge zirconium particles are pressed into sponge zirconium ingots, so that the blowout splashing phenomenon caused by intense reaction is avoided, and the phenomenon that viscous substances appearing on the liquid level after melting are difficult to remove is also avoided; during charging, most of the electrolytic copper plates are added to the furnace bottom, then the sponge zirconium ingot is placed on the electrolytic copper plates, a plurality of electrolytic copper plates are placed on the sponge zirconium ingot, the sponge zirconium ingot is clamped between the copper plates, and splashing is not prone to occurring during smelting; vacuumizing, starting to supply power to the furnace to increase power, and waiting for complete melting of the electrolytic copper plate and the sponge zirconium ingot; in the alloying process, if the blowout splashing phenomenon occurs, power transmission is stopped, and after the liquid level recovers to be calm, power transmission is conducted again; viscous substances appearing on the liquid surface in the later-stage refining process are effectively removed, and the mirror surface phenomenon appears on the copper liquid surface; and after vacuum melting is completed, pouring is conducted, and the copper-zirconium intermediate alloy formed through pouring is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of copper master alloys, and in particular relates to a method for preparing a copper-zirconium master alloy. Background Art

[0002] Copper-chromium-zirconium alloy has high strength, high conductivity, high corrosion resistance, wear resistance and excellent hot and cold processing properties. In recent years, due to its excellent properties, it has been widely used in DC and AC motors required by high-speed rail, ships, mining, wind energy and industrial fields. At present, most of the plates, wires and bars produced by copper-chromium-zirconium alloy have changed from vacuum melting technology to non-vacuum semi-continuous casting technology. Although the copper-chromium-zirconium alloy ingots produced by non-vacuum semi-continuous casting are not as good as vacuum cast copper-chromium-zirconium alloy in terms of final oxygen content and physical and chemical properties, its production cost is greatly reduced and its market applicability is stronger. In the process of producing copper-chromium-zirconium alloy ingots by non-vacuum semi-continuous casting, the addition of element zirconium is a key technical issue in its overall production technology.

[0003] The general method now is to add copper-zirconium master alloy. The key to the production technology of copper-zirconium master alloy lies in four production steps, which are as follows: 1. How to add sponge zirconium; 2. When to fill argon; 3. What is the pouring temperature; 4. What is the pouring speed. The traditional production steps of copper-zirconium master alloy are as follows: first, insert the weighed electrolytic copper plate tightly into the crucible, then put the weighed sponge zirconium into the secondary feeding bin, wait for the secondary feeding, and then evacuate. When the vacuum reaches less than 1000Pa, start to send electricity for heating, wait for the electrolytic copper plate to be completely melted, fill argon until the vacuum in the furnace is 1000-2000Pa, and add sponge zirconium through the secondary feeding bin in 4-5 times. Each time you add it, you need to wait for the sponge zirconium to be completely melted before adding the next time. After all the sponge zirconium is added, adjust the pouring temperature and pour quickly.

[0004] In the traditional copper-zirconium master alloy smelting technology, there is a difficult problem to solve, that is, after adding zirconium sponge, due to the intense alloying of zirconium sponge particles with copper liquid, a layer of viscous substance will appear on the surface of copper liquid. This substance covers the copper liquid surface, not only causing inaccurate visual pouring temperature, but also sticking to the crucible wall, which is difficult to clean. When waiting for the next smelting, the charge will bring in oxidized slag. If the problem of this viscous substance is not solved, the yield and quality of the smelted copper-zirconium master alloy ingot will be greatly affected. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a copper-zirconium master alloy, which solves the problem that the traditional copper-zirconium master alloy smelting technology causes a viscous substance to appear on the copper liquid surface, resulting in inaccurate pouring temperature and bringing oxide slag into the next smelting furnace.

[0006] The present invention is achieved through the following technical solutions: The invention discloses a method for preparing a copper-zirconium master alloy, comprising the following steps: S1. Select zirconium sponge particles with zirconium content > 99.4% and particle size of 10-40mm; pressing the zirconium sponge particles into a zirconium sponge ingot; S2. When charging the furnace, first add most of the electrolytic copper plates to the bottom of the furnace, then place the zirconium sponge ingot on the electrolytic copper plates, and then place several electrolytic copper plates on the zirconium sponge ingot; S3, vacuumize, start to supply power to the furnace, and wait for the electrolytic copper plate and sponge zirconium ingot to be completely melted; if blowout and splashing occur during the alloying process, stop supplying power, and supply power again after the liquid level returns to calm; S4. After vacuum melting is completed, pouring is performed to obtain a cast copper-zirconium intermediate alloy.

[0007] Further, in S2, the electrolytic copper plate is pre-cut into block copper plates.

[0008] Furthermore, in S3, the furnace is evacuated, and after the vacuum in the furnace reaches 1000Pa, the furnace starts to supply power. Furthermore, in S3, the specific process of power transmission and power addition is: the initial power is 10kw, and 10kw is added every 10 minutes until the power transmission is adjusted to 40kw, waiting for the charge to melt.

[0009] Furthermore, in S3, stopping heating specifically includes: shutting down the pump group of the smelting furnace, starting the damper valve, and stopping power supply.

[0010] Furthermore, in S3, the power is supplied again as follows: the pump group of the smelting furnace is opened again to start the damper valve, and the power is supplied to 40kw and maintained for 10-15 minutes.

[0011] Further, in S4, the pouring temperature is 980-1180°C.

[0012] Further, in S4, the pouring speed is 0.5-6.5 kg / s.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: The invention discloses a method for preparing a copper-zirconium master alloy. When charging a furnace, a large portion of an electrolytic copper plate is first added to the bottom, and then a sponge zirconium ingot is placed on the copper plate, and then the copper plate is placed on the sponge zirconium ingot. The sponge zirconium ingot can be sandwiched between the copper plates, and is not easy to splash during smelting. The key is to use sponge zirconium particles to be converted into sponge zirconium ingots through a press. The present invention has been verified by design that when the particle size is 10-40 mm, the sponge zirconium ingot will not cause the phenomenon of blowout and splashing due to intense reaction during the alloying process, nor will it cause the phenomenon that the viscous substances on the liquid surface after melting are difficult to remove; In the traditional process, the argon filling time generally starts after all the electrolytic copper plates are melted. On the one hand, it will be difficult to remove the viscous material on the liquid surface during refining, and on the other hand, the gas content removed from the melt will be greatly reduced. The method of the present invention is that when the charge is completely melted, if a blowout and splashing phenomenon occurs during the alloying process, the heating should be stopped immediately, and the liquid level should be heated again after it returns to calm. This method effectively removes the viscous material that appears on the liquid surface during the later refining process, so that the copper liquid surface appears a mirror phenomenon, and when the pouring temperature is adjusted later, the pouring temperature can be accurately judged. The yield rate of alloy ingots is greatly improved. Moreover, after the pouring is completed, the graphite crucible will not adhere to the viscous material, the crucible wall is relatively clean, and the oxide slag will not enter the charge during the next furnace smelting.

[0014] Furthermore, the present invention also optimizes the pouring temperature, which is designed to be 980-1180°C. At the same pouring speed, the higher the pouring temperature, the more bubbles there are on the end face of the ingot, and the greater the probability of the zirconium element reacting with the graphite. The lower the pouring temperature, the fewer bubbles there are on the end face of the ingot, but the worse the surface quality of the side face.

[0015] Furthermore, the present invention also optimizes the pouring speed, which is designed to be 0.5-6.5 kg / s. The higher the pouring speed, the more uniform the zirconium content, but the more bubbles on the end surface, and the lower the pouring speed, the more non-uniform the zirconium content, but the fewer bubbles on the end surface. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the present invention clearer, the following is further described in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments.

[0017] The detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention claimed for protection, but merely represents a selected embodiment of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0018] The features and performances of the present invention are further described in detail below in conjunction with the embodiments.

[0019] Example 1 The invention discloses a method for preparing a copper-zirconium master alloy, comprising the following steps: S1. Prepare raw materials: Use No. 1 electrolytic copper plate and cut it into small pieces of 100×100×10mm.

[0020] The zirconium sponge has a zirconium content of >99.4% and a particle size of 10mm. The zirconium sponge particles are pressed into zirconium sponge ingots using a hydraulic press; S2. Loading the furnace When loading the furnace, most of the small copper plates should be added to the bottom of the furnace first, and then the sponge zirconium ingot should be placed on the copper plate, and then two more copper plates should be placed on the sponge zirconium ingot until all the materials are loaded.

[0021] S3. Vacuum melting Evacuate until the vacuum reaches less than 1000Pa, start heating with electricity, and wait until the electrolytic copper plate and sponge zirconium ingot are completely melted; S4. After vacuum melting is completed, pouring is performed at a pouring temperature of 980° C. and a pouring speed of 1.5 kg / s to obtain a cast copper-zirconium intermediate alloy.

[0022] Example 2 The invention discloses a method for preparing a copper-zirconium master alloy, comprising the following steps: S1. Prepare raw materials: Use No. 1 electrolytic copper plate and cut it into small pieces of 100×100×10mm.

[0023] The zirconium sponge has a zirconium content of >99.4% and a particle size of 20mm. The zirconium sponge particles are pressed into zirconium sponge ingots using a hydraulic press; S2. Loading the furnace When loading the furnace, most of the small copper plates should be added to the bottom of the furnace first, and then the sponge zirconium ingot should be placed on the copper plate, and then two more copper plates should be placed on the sponge zirconium ingot until all the materials are loaded.

[0024] S3. Vacuum melting Evacuate until the vacuum reaches less than 1000Pa, start heating with electricity, and wait until the electrolytic copper plate and sponge zirconium ingot are completely melted; S4. After vacuum melting is completed, pouring is performed at a pouring temperature of 1030° C. and a pouring speed of 1.5 kg / s to obtain a cast copper-zirconium master alloy.

[0025] Example 3 The invention discloses a method for preparing a copper-zirconium master alloy, comprising the following steps: S1. Prepare raw materials: Use No. 1 electrolytic copper plate and cut it into small pieces of 100×100×10mm.

[0026] The zirconium sponge has a zirconium content of >99.4% and a particle size of 20mm. The zirconium sponge particles are pressed into zirconium sponge ingots using a hydraulic press; S2. Loading the furnace When loading the furnace, most of the small copper plates should be added to the bottom of the furnace first, and then the sponge zirconium ingot should be placed on the copper plate, and then two more copper plates should be placed on the sponge zirconium ingot until all the materials are loaded.

[0027] S3. Vacuum melting Evacuate until the vacuum reaches less than 1000Pa, start heating with electricity, and wait until the electrolytic copper plate and sponge zirconium ingot are completely melted; S4. After vacuum melting is completed, pouring is performed at a pouring temperature of 1080° C. and a pouring speed of 1.5 kg / s to obtain a cast copper-zirconium master alloy.

[0028] Example 4 The invention discloses a method for preparing a copper-zirconium master alloy, comprising the following steps: S1. Prepare raw materials: Use No. 1 electrolytic copper plate and cut it into small pieces of 100×100×10mm.

[0029] The zirconium sponge has a zirconium content of >99.4% and a particle size of 30mm. The zirconium sponge particles are pressed into zirconium sponge ingots using a hydraulic press; S2. Loading the furnace When loading the furnace, most of the small copper plates should be added to the bottom of the furnace first, and then the sponge zirconium ingot should be placed on the copper plate, and then two more copper plates should be placed on the sponge zirconium ingot until all the materials are loaded.

[0030] S3. Vacuum melting Evacuate until the vacuum reaches less than 1000Pa, start heating with electricity, and wait until the electrolytic copper plate and sponge zirconium ingot are completely melted; S4. After vacuum melting is completed, pouring is performed at a pouring temperature of 1130° C. and a pouring speed of 1.5 kg / s to obtain a cast copper-zirconium master alloy.

[0031] Example 5 The invention discloses a method for preparing a copper-zirconium master alloy, comprising the following steps: S1. Prepare raw materials: Use No. 1 electrolytic copper plate and cut it into small pieces of 100×100×10mm.

[0032] The zirconium sponge has a zirconium content of >99.4% and a particle size of 20mm. The zirconium sponge particles are pressed into zirconium sponge ingots using a hydraulic press; S2. Loading the furnace When loading the furnace, most of the small copper plates should be added to the bottom of the furnace first, and then the sponge zirconium ingot should be placed on the copper plate, and then two more copper plates should be placed on the sponge zirconium ingot until all the materials are loaded.

[0033] S3. Vacuum melting Evacuate until the vacuum reaches less than 1000Pa, start heating with electricity, and wait until the electrolytic copper plate and sponge zirconium ingot are completely melted; S4. After vacuum melting is completed, pouring is performed at a pouring temperature of 1180° C. and a pouring speed of 1.5 kg / s to obtain a cast copper-zirconium master alloy.

[0034] In Examples 1-5, if a blowout splash occurs during the alloying process of S3, the pump group of the smelting furnace should be immediately closed to start the damper valve, and the power supply should be stopped immediately. After the liquid level returns to calm, the pump group should be opened to start the damper valve, and the power should be supplied to 40kw for 10 minutes.

[0035] This method effectively removes the sticky substances that appear on the liquid surface during the later refining process, making the copper liquid surface appear as a mirror. When adjusting the pouring temperature later, the pouring temperature can be accurately judged. The yield rate of alloy ingots is greatly improved.

[0036] Moreover, after pouring, the graphite crucible will not stick to sticky substances, the crucible wall is relatively clean, and the oxide slag will not enter the charge during the next smelting. The yield and quality of the smelted copper-zirconium master alloy ingot are greatly improved.

[0037] Ingot quality of copper-zirconium master alloy prepared in Example 1-5 When the traditional process produces copper-zirconium master alloy, it is not easy to judge the melt temperature because there is always a viscous substance covering the copper liquid. In addition, this viscous substance will keep the melt problem, and it is not easy to adjust the pouring temperature in the later stage. After using the new process, a mirror phenomenon appears on the liquid surface, which is easy to judge the melt temperature. Therefore, the present invention designs five pouring temperatures of 980°C, 1030°C, 1080°C, 1130°C, and 1180°C, and the same pouring speed is 1.5kg / s for testing. Through the comparison of the ingot quality after the test, it is determined that the pouring temperature is 980°C as the optimal pouring temperature. At the same pouring speed, the higher the pouring temperature, the more bubbles on the end face of the ingot, and the greater the probability of the zirconium element reacting with graphite. The lower the pouring temperature, the fewer bubbles on the end face of the ingot, but the worse the surface quality of the side.

[0038] Example 7 On the basis of Example 1, the pouring speed was adjusted to 0.5 kg / s to obtain a cast copper-zirconium intermediate alloy.

[0039] Example 8 On the basis of Example 1, the pouring speed was adjusted to 3.5 kg / s to obtain a cast copper-zirconium intermediate alloy.

[0040] Example 9 On the basis of Example 1, the pouring speed was adjusted to 5.5 kg / s to obtain a cast copper-zirconium intermediate alloy.

[0041] Example 10 On the basis of Example 1, the pouring speed was adjusted to 6.5 kg / s to obtain a cast copper-zirconium intermediate alloy.

[0042] In the traditional process, during the pouring process, the viscous material will be poured into the mold together with the melt, and the liquid column is sometimes thin and sometimes thick, so it is difficult to control the pouring speed. In the pouring process of the new process, the liquid column can be stably controlled. Experiments were designed. The same pouring temperature was 980°C, and the pouring speeds were set to 0.5 kg / s, 1.5 kg / s, 3.5 kg / s, 5.5 kg / s, and 6.5 kg / s, respectively. Experiments were carried out, corresponding to Examples 1 and Examples 7-10.

[0043] By comparing the ingot quality after the test, it was determined that the pouring speed of 1.5kg / s was the best pouring speed. The higher the pouring speed, the more uniform the zirconium content, but the more bubbles on the end surface; the lower the pouring speed, the more uneven the zirconium content, but the fewer bubbles on the end surface.

[0044] Comparative Example 1 A method for preparing a copper-zirconium master alloy comprises the following steps: S1. Prepare raw materials: Use No. 1 electrolytic copper plate and cut it into small pieces of 100×100×10mm.

[0045] The zirconium sponge has a zirconium content of >99.4% and a particle size of 50mm. The zirconium sponge particles are pressed into zirconium sponge ingots using a hydraulic press; S2. Loading the furnace When loading the furnace, most of the small copper plates should be added to the bottom of the furnace first, and then the sponge zirconium ingot should be placed on the copper plate, and then two more copper plates should be placed on the sponge zirconium ingot until all the materials are loaded.

[0046] S3. Vacuum melting Evacuate until the vacuum reaches less than 1000Pa, start heating with electricity, and wait until the electrolytic copper plate and sponge zirconium ingot are completely melted; Due to the large particle size of sponge zirconium, during smelting, the reaction was intense and splashing occurred, and a viscous substance appeared on the liquid surface after melting.

[0047] S4. After vacuum melting is completed, pouring is performed at a pouring temperature of 980° C. and a pouring speed of 1.5 kg / s to obtain a copper-zirconium intermediate alloy.

[0048] Blowout and splashing also occurred during the alloying process, and sticky substances were adhered to the graphite crucible.

[0049] Comparative Example 2 Based on Example 1, no zirconium sponge ingot is prepared.

[0050] During the S3 vacuum melting and alloying process, viscous substances appeared. This was because during the melting, the reaction was intense and splashing occurred, and viscous substances appeared on the liquid surface after melting.

[0051] By comparing the control example 1 with the embodiment 1 of the present invention, it can be seen that in the process designed by the present invention, it is key to convert the sponge zirconium particles into sponge zirconium ingots through a press. Through a large number of experiments, it is verified that when the particle size is 10-40mm, the zirconium ingot will not cause the blowout and splashing phenomenon due to the fierce reaction during the alloying process, nor will it cause the viscous material on the liquid surface after melting to be difficult to remove.

[0052] By adopting the process improvement method proposed in the present invention, in the production process of 10-ton batches of copper-zirconium intermediate alloy in a certain factory, the final yield rate was increased from the original 60% to the current 90%, and through this improved technical invention, a total net profit of more than 300,000 yuan was obtained in the supply process of this batch of copper-zirconium intermediate alloy.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a copper-zirconium master alloy, characterized in that: The following steps are involved: S1. Select zirconium sponge particles with zirconium content > 99.4% and particle size of 10-40mm; pressing the zirconium sponge particles into a zirconium sponge ingot; S2. When charging the furnace, first add most of the electrolytic copper plates to the bottom of the furnace, then place the zirconium sponge ingot on the electrolytic copper plates, and then place several electrolytic copper plates on the zirconium sponge ingot; S3, vacuumize, start to supply power to the furnace, and wait for the electrolytic copper plate and sponge zirconium ingot to be completely melted; if blowout and splashing occur during the alloying process, stop supplying power, and supply power again after the liquid level returns to calm; S4. After vacuum melting is completed, pouring is performed to obtain a cast copper-zirconium intermediate alloy.

2. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S2, the electrolytic copper plate is pre-cut into block copper plates.

3. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S3, the furnace is evacuated, and after the vacuum in the furnace reaches 1000Pa, the furnace starts to supply electricity and increase power.

4. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S3, the specific process of power transmission and power addition is: the initial power is 10kw, and 10kw is added every 10 minutes until the power transmission is adjusted to 40kw, waiting for the charge to melt.

5. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S3, stopping heating specifically includes: shutting down the pump group of the smelting furnace, starting the damper valve, and stopping power supply.

6. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S3, the power is supplied again as follows: the pump group of the smelting furnace is opened again to start the damper valve, and the power is supplied to 40kw and maintained for 10-15 minutes.

7. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S4, the pouring temperature is 980-1180°C.

8. The method for preparing a copper-zirconium master alloy according to claim 1, characterized in that: In S4, the pouring speed is 0.5-6.5 kg / s.