Preparation method of high-performance microalloyed anode steel claw

Abstract

The invention relates to the technical field of anode steel claws, and discloses a preparation method of a high-performance microalloyed anode steel claw, which comprises the following steps: S1, taking waste steel, a waste anode steel claw and waste square steel as raw materials, melting to obtain a melt, and adding a niobium element during smelting; s2, in the step S1, slagging-off is carried out when melt is formed through smelting, a slagging constituent is added before tapping, and standing and slag suction are carried out; and S3, the melt is poured, pressure maintaining treatment is conducted after pouring, and the anode steel claw is obtained after natural cooling. The microalloying element Nb is added, so that the microstructure of the steel can be changed, grains can be refined, dislocation movement can be prevented, and the strength and hardness of the alloy are remarkably improved; niobium can inhibit precipitation of chromium carbide, so that the corrosion resistance of the steel is improved.

Description

Technical Field

[0001] The invention relates to the technical field of anode steel claws, and in particular to a method for preparing a high-performance micro-alloyed anode steel claw. Background Art

[0002] Anode steel claws are an indispensable device in the electrolytic aluminum industry. As one of the important parts of anode assembly, the voltage drop of anode steel claws affects the power consumption per ton of aluminum. If the voltage drop is large, it means that more electrical energy is converted into heat energy and consumed, which leads to a decrease in the efficiency of electrical energy utilization and increases the power consumption cost per ton of aluminum. Therefore, in order to improve the energy efficiency of the electrolytic process and reduce power consumption, it is necessary to reduce the voltage drop of anode steel claws as much as possible. At the same time, electrolytic aluminum anode steel claws are also important conductive components in the electrolytic aluminum industry, which include steel claws, aluminum guide rods, and anode carbon blocks. These parts together form the anode guide rod group, which serves as a bridge to connect the anode and transmit current. The average operation time of anode cast steel claws on the production line can reach more than ten cycles, so they must have sufficient strength and good electrical conductivity, and the electrical conductivity of the steel claws directly affects the production efficiency and economic benefits of electrolytic aluminum. Therefore, the improvement of the conductivity and corrosion resistance of the anode steel claws during service has become the top priority of the optimization of electrolytic aluminum anode steel claws.

[0003] At present, there has been a certain degree of progress and application results in the research field of anode steel claws. The anode materials currently used can reduce production costs and extend the life of the anode, effectively solving the short life and high energy consumption problems of traditional anode materials. The research technology of anode steel claws on the market has continued to mature, and the quality has been significantly improved, and certain achievements have been made, but the current research has not yet reached the scale and level of industrial production, and further in-depth research is still needed to improve the life and performance of anode steel claws. Summary of the invention

[0004] Technical Problems Solved by the Invention

[0005] Used to improve the service life, conductivity and corrosion resistance of anode steel claws.

[0006] Technical solution adopted by the present invention

[0007] In the present invention, Nb is added to the anode steel claw. The Nb element can form niobium carbide (NbC) with carbon. These carbide particles can precipitate at the grain boundary and in the crystal, which plays a role in refining the grains and preventing dislocation movement, thereby significantly improving the strength and hardness of the alloy. Niobium atoms can dissolve in the iron matrix to form a solid solution, and improve the strength of the alloy through the solid solution strengthening mechanism. Niobium is an important metal element with a wide range of uses and applications in alloys. In the field of superconductivity, niobium is often used as a wire and cable material. It has excellent superconducting properties at low temperatures and can withstand high current density. Niobium has excellent corrosion resistance and can be used in the manufacture of chemical equipment, rocket propellants and other fields with high requirements for corrosion resistance. Niobium is also widely used in electronic components and integrated circuits. Due to niobium's high melting point, good conductivity, oxidation resistance and heat resistance, it can be used to manufacture capacitors, resistors, transistors, etc. It can significantly improve its high temperature strength and corrosion resistance in high-temperature alloys, steel smelting and casting alloys, and superconducting alloys. Niobium is the main element that reduces the austenite zone and can stabilize the ferrite structure over a wide temperature range. Ferrite has a low carbon content and low resistivity. Adding an appropriate amount of niobium to stainless steel can inhibit the precipitation of chromium carbides, thereby improving the corrosion resistance of the steel, making it highly corrosion resistant. In addition, niobium can also form a stable oxide layer in certain high-temperature alloys, further enhancing oxidation and corrosion resistance.

[0008] To expand on this, it means:

[0009] First, the present invention provides a method for preparing a high-performance microalloyed anode steel claw, comprising the following steps:

[0010] S1 uses scrap steel, scrap anode steel claws and scrap square steel as raw materials, and obtains a melt by melting. Niobium is added during smelting.

[0011] S2 In S1, slag is removed when the melt is formed, and slag-forming agent is added 1 to 3 minutes before the melt is discharged from the furnace, and the slag is absorbed by standing;

[0012] S3 pours the melt, performs pressure maintenance after pouring, and obtains the anode steel claw after natural cooling.

[0013] According to some preferred embodiments, in S1, the melting temperature is 1658-1754°C.

[0014] According to some preferred embodiments, in S1, the melt is a ZG200-400 grade melt.

[0015] According to some preferred embodiments, in S1, the melt composition of ZG200-400 grade is: Al 0.1-0.20%, Cu 0.01-0.05%, Cr 0.01-0.06%, Si 0.10-0.30%, Mn 0.10-0.50%, C 0.1-0.20%, Ni 0.01-0.04%, P 0.01-0.03%, S 0.01-0.03%, Ti 0.01-0.02%, V 0.01-0.03%, B 0.01-0.03%, and the balance is Fe and unavoidable impurities.

[0016] According to some preferred embodiments, in S1, the niobium element is added in the form of ferroniobium alloy.

[0017] According to some preferred embodiments, in S1, the ferroniobium alloy is added at one time, when the furnace smelting temperature is 1400-1500° C., the ferroniobium alloy is added, and the amount added in a single furnace is 5-10 kg.

[0018] According to some preferred embodiments, in S2, the slag-forming agent comprises 70-75wt% SiO 2 , 15-18wt% Al 2 O 3 , 3-5wt% CaO, the remainder being metal impurities.

[0019] According to some preferred embodiments, in S3, the casting is performed by lost foam casting in a prefabricated sand box.

[0020] According to some preferred implementations, in S3, after pouring is completed, the pressure is maintained for 10-15 minutes, and the parts are naturally cooled for 2-3 days before being unpacked.

[0021] Second, the present invention provides an anode steel claw obtained by the aforementioned preparation method.

[0022] Beneficial effects achieved by the present invention

[0023] The present invention can change the microstructure of steel by adding the microalloying element Nb, and can also refine the grains and prevent the movement of dislocations, thereby significantly improving the strength and hardness of the alloy; niobium can inhibit the precipitation of chromium carbides, thereby improving the corrosion resistance of steel. In addition, niobium can also form a stable oxide layer in the high-temperature alloy, further enhancing the oxidation resistance and corrosion resistance. The anode steel claw obtained by the preparation method of the present invention has higher conductivity and stronger corrosion resistance, improves the production efficiency of electrolytic aluminum, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a metallographic photograph of Nb-iron alloy;

[0025] Figure 2 This is the microstructure diagram of Nb iron alloy. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0027] Example 1

[0028] This embodiment provides a method for preparing a high-performance microalloyed anode steel claw with added microalloying element Nb. The specific preparation steps are as follows:

[0029] (1) Using scrap steel, scrap anode steel claws, and scrap square steel, the required amount of each raw material is calculated according to the ZG200-400 alloy composition determined above;

[0030] (2) Scrap steel, scrap anode steel claws and scrap square steel are melted at 1658-1754° C. to obtain a ZG200-400 alloy melt, wherein the composition of the ZG200-400 alloy melt includes, by mass ratio, 0.109% Al, 0.041% Cu, 0.051% Cr, 0.266% Si, 0.404% Mn, 0.162% C, 0.034% Ni, 0.027% P, 0.026% S, 0.014% Ti, 0.025% V, 0.027% B, and the balance is Fe and unavoidable impurities;

[0031] (3) Adding ferroniobium alloy to the ZG200-400 melt in the furnace, wherein the mass content of Nb in the ferroniobium alloy is 65.51%. The ferroniobium alloy is added at one time, when the furnace smelting temperature is 1400-1500°C, the ferroniobium alloy is added, the amount added in a single furnace is 5-10kg, and the content is 0.01% of the total mass;

[0032] (4) When the melt is formed, the slag is removed, and a slag-forming agent is added 3 minutes before the melt is discharged from the furnace, and the slag is sucked at rest;

[0033] (5) The melt is poured into a prefabricated sand box for lost foam casting. After the pouring is completed, the pressure is maintained for 10 minutes. After natural cooling for 3 days, the box is turned over and the parts are taken out to obtain high-performance micro-alloyed anode steel claws.

[0034] (6) The obtained samples were sampled for metallographic observation, and the resistivity of the steel claw samples was tested using a variable temperature resistivity test system (RMS_1000). The corrosion resistance test and oxidation resistance test were performed at 600°C.

[0035] Example 2

[0036] This embodiment provides a method for preparing a high-performance microalloyed anode steel claw with added microalloying element Nb. The specific preparation steps are as follows:

[0037] (1) Using scrap steel, scrap anode steel claws, and scrap square steel, the required amount of each raw material is calculated according to the ZG200-400 alloy composition determined above;

[0038] (2) melting scrap steel, scrap anode steel claws and scrap square steel at 1658-1754° C. to obtain a ZG200-400 alloy melt, wherein the composition of the ZG200-400 alloy melt includes, by mass ratio, 0.109% Al, 0.041% Cu, 0.051% Cr, 0.266% Si, 0.404% Mn, 0.162% C, 0.034% Ni, 0.027% P, 0.026% S, 0.014% Ti, 0.025% V, 0.027% B, and the balance is Fe and unavoidable impurities;

[0039] (3) Adding ferroniobium alloy to the ZG200-400 melt in the furnace, wherein the mass content of Nb in the ferroniobium alloy is 65.51%. The ferroniobium alloy is added at one time, when the furnace smelting temperature is 1400-1500°C, the ferroniobium alloy is added, the amount added in a single furnace is 5-10kg, and the content is 0.02% of the total mass;

[0040] (4) When the melt is formed, the slag is removed, and a slag-forming agent is added 3 minutes before the melt is discharged from the furnace, and the slag is sucked at rest;

[0041] (5) pouring the melt into a prefabricated sand box for lost foam casting, maintaining the pressure for 10 minutes after the pouring is completed, and then turning the box over after natural cooling for 3 days to obtain a high-performance micro-alloyed anode steel claw;

[0042] (6) The obtained samples were sampled for metallographic observation, and the resistivity of the steel claw samples was tested using a variable temperature resistivity test system (RMS_1000). The corrosion resistance test and oxidation resistance test were performed at 600°C.

[0043] The test results of Example 1-2 are shown in Table 1.

[0044] Table 1

[0045]

[0046] Figure 1 This is a metallographic photograph of Nb iron alloy.

[0047] Depend on Figure 1It can be seen that the grain size is relatively uniform, but it cannot reflect the organizational characteristics of hypoeutectoid steel. The distribution of chemical elements in the sample is uneven, especially Al, Cr and C, but the morphology of the raw material particles and the particle size after the reaction are basically the same, which shows that Cr does not participate in the microalloying process, but is still the morphology and composition of the raw material, and has little effect on the structure.

[0048] Figure 2 This is the microstructure diagram of Nb iron alloy.

[0049] Depend on Figure 2 It can be seen that the main grain structure is α-ferrite, and there are obvious pearlite structure characteristics locally, which is the morphology of cast hypoeutectoid steel.

Claims

1. A method for preparing a high-performance microalloyed anode steel claw, characterized in that: The steps include: S1 uses scrap steel, scrap anode steel claws and scrap square steel as raw materials, and obtains a melt by melting. Niobium is added during smelting. S2 In S1, slag is removed when the melt is formed, and slag-forming agent is added before the melt is discharged from the furnace, and the slag is absorbed while the melt is allowed to stand. S3 pours the melt, performs pressure maintenance after pouring, and obtains the anode steel claw after natural cooling.

2. The method for preparing a high performance microalloyed anode steel claw according to claim 1, characterized in that: In S1, the melting temperature is 1658-1754°C.

3. The method for preparing a high performance microalloyed anode steel claw according to claim 1, characterized in that: In S1, the melt is a ZG200-400 grade melt.

4. The method for preparing a high performance microalloyed anode steel claw according to claim 3, characterized in that: In S1, the melt composition of ZG200-400 grade is: Al 0.1-0.20%, Cu 0.01-0.05%, Cr 0.01-0.06%, Si 0.10-0.30%, Mn 0.10-0.50%, C 0.1-0.20%, Ni 0.01-0.04%, P 0.01-0.03%, S 0.01-0.03%, Ti 0.01-0.02%, V 0.01-0.03%, B 0.01-0.03%, and the balance is Fe and unavoidable impurities.

5. The method for preparing a high performance microalloyed anode steel claw according to claim 1, characterized in that: In S2, the slag-forming agent includes 70-75wt% SiO2, 15-18wt% Al2O3, 3-5wt% CaO, and the remainder is metal impurities.

6. The method for preparing a high performance microalloyed anode steel claw according to claim 1, characterized in that: In S3, the casting is carried out in a prefabricated sand box by lost foam casting.

7. The method for preparing a high performance microalloyed anode steel claw according to any one of claims 1 to 6, characterized in that: In S1, niobium is added in the form of ferroniobium alloy.

8. The method for preparing a high performance microalloyed anode steel claw according to claim 7, characterized in that: In S1, ferroniobium alloy is added at one time. When the furnace smelting temperature is 1400-1500°C, ferroniobium alloy is added. The amount added in a single furnace is 5-10 kg.

9. An anode steel claw obtained by the preparation method according to any one of claims 1 to 8.

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