A nickel-magnesium spheroidizing agent cored wire

Abstract

This invention discloses a nickel-magnesium spheroidizing agent cored wire, relating to the technical field of cored wires. The nickel-magnesium spheroidizing agent cored wire comprises an outer sheath and a core agent encased within the outer sheath; the core agent comprises the following components in parts by weight: 98-99 parts of nickel-magnesium spheroidizing agent and 1-2 parts of a composite desulfurizing agent, wherein the composite desulfurizing agent comprises an Al-Mg-CaO-CaC2 mixture, and the Al-Mg-CaO-CaC2 mixture comprises the following components in parts by weight: 18-24 parts CaO, 8-15 parts CaC2, 50-60 parts Mg, and 12-22 parts Al. The preparation method includes: uniformly mixing the nickel-magnesium spheroidizing agent and the composite desulfurizing agent to obtain the core agent; using a cored wire forming machine to encase the core agent in a steel strip, forming an outer sheath, thus obtaining the nickel-magnesium spheroidizing agent cored wire. The cored wire prepared by this application not only has excellent desulfurization effect and reduces the loss of Mg in the nickel-magnesium spheroidizing agent, but also has better spheroidizing effect.

Description

Technical Field

[0001] This invention relates to the technical field of cored wires, and in particular to a nickel-magnesium spheroidizing agent cored wire. Background Technology

[0002] Spheroidizing agents are certain metals or alloys added to molten iron to obtain spheroidal graphite cast iron. Cored wire is made by wrapping alloy powder around a strip of steel. Because it is difficult to control the amount of spheroidizing agent added to molten iron, and there is a risk of molten iron splashing, posing a safety hazard, a wire feeder is generally used to feed spheroidizing agent-coated wire into the molten iron.

[0003] Currently, the most commonly used nickel-magnesium spheroidizing agent cored wires on the market have a core diameter of 13mm and a magnesium content of ≤30% in the core agent. The nickel-magnesium spheroidizing agents in these cored wires mainly fall into two categories: 1. NiMg15-Ni: 81-85%, Mg: 14-16%; 2. NiMg17-Ni: 81-85%, Mg: 16-19%. These nickel-magnesium spheroidizing agent cored wires are used for deoxidation and modification treatment of certain special alloys, as well as for spheroidizing agents in casting rolls.

[0004] Since sulfur plays a reverse spheroidizing role in ductile iron, it reacts with magnesium in nickel-magnesium spheroidizing agents to form compounds, resulting in magnesium loss and affecting the spheroidizing effect. Therefore, it is necessary to reduce the influence of sulfur on the spheroidizing process. Summary of the Invention

[0005] To reduce the loss of magnesium in nickel-magnesium spheroidizing agents due to sulfur, this application provides a nickel-magnesium spheroidizing agent cored wire.

[0006] In a first aspect, this application provides a nickel-magnesium spheroidizing agent cored wire, which adopts the following technical solution:

[0007] A nickel-magnesium spheroidizing agent cored wire includes an outer sheath and a core agent wrapped within the outer sheath; based on the total weight of the core agent, the core agent comprises the following components in parts by weight: 98-99 parts of nickel-magnesium spheroidizing agent and 1-2 parts of composite desulfurizing agent, wherein the composite desulfurizing agent comprises an Al-Mg-CaO-CaC2 mixture, and based on the total weight of the Al-Mg-CaO-CaC2 mixture, the Al-Mg-CaO-CaC2 mixture comprises the following components in parts by weight: 18-24 parts of CaO, 8-15 parts of CaC2, 50-60 parts of Mg, and 12-22 parts of Al.

[0008] By adopting the above technical solution, the Al-Mg-CaO-CaC2 mixture is formed by fusing Al-Mg mixture with CaO and CaC2. CaC2 has a melting point of approximately 447℃, and CaO has a melting point of approximately 2572℃, while the temperature of molten iron is 1350-1450℃. Therefore, fusing CaC2 and CaO lowers the melting point, allowing the composite desulfurizing agent to fuse smoothly in the molten iron. Since Mg is added to the molten iron in a fused state with Al, CaO, and CaC2, its physical properties are altered, which helps to slow down the vaporization rate of Mg. Furthermore, Al can react with oxygen in the molten iron, thereby adjusting the O / S ratio in the molten iron, reducing the oxidative burning loss of Mg, improving Mg utilization, and facilitating the desulfurization reaction.

[0009] Different proportions of the components in the Al-Mg-CaO-CaC2 mixture result in different melting points and desulfurization effects. Through experiments, this application found that by controlling the proportions of the components in the Al-Mg-CaO-CaC2 mixture within the above-mentioned range under the above-mentioned ratios of nickel-magnesium spheroidizing agent and composite sulfurizing agent, the prepared Al-Mg-CaO-CaC2 mixture not only has a melting point between 1362-1425℃, but also has excellent desulfurization effect, enabling the nickel-magnesium sulfurizing agent cored wire of this application to achieve a good spheroidization effect.

[0010] Therefore, the cored wire of this application not only has excellent desulfurization effect, but also reduces the loss of Mg in the nickel-magnesium spheroidizing agent, resulting in better spheroidizing effect.

[0011] In one specific feasible embodiment, the Al-Mg-CaO-CaC2 mixture is prepared according to the following steps:

[0012] Melting: Al and Mg are melted and mixed to obtain an Al-Mg melt;

[0013] Preparation of the mixture: CaO and CaC2 are heated to 800-1200℃ under vacuum, then added to the Al-Mg melt, stirred until homogeneous, and then cooled to room temperature to obtain the Al-Mg-CaO-CaC2 mixture.

[0014] By employing the above technical solution, heating CaO and CaC2 under vacuum helps remove moisture, increases the dissolution rate of CaO and CaC2, and reduces the formation of calcium cyanamide from nitrogen in the air. First, Al and Mg are made into an Al-Mg melt, and then CaO and CaC2 are mixed evenly with the Al-Mg melt, which helps to make the components more uniformly mixed, thereby improving the material homogeneity of the Al-Mg-CaO-CaC2 mixture.

[0015] In one specific implementation, the composite desulfurizing agent further includes CaF2, which forms an outer layer encapsulating the Al-Mg-CaO-CaC2 mixture.

[0016] By adopting the above technical solution, CaF2, with a melting point of approximately 1402℃, possesses excellent wear resistance and moisture-proof properties. Therefore, using CaF2 to form a coating layer on the outside of the Al-Mg-CaO-CaC2 mixture can reduce moisture absorption during storage and also reduce wear on the Al-Mg-CaO-CaC2 mixture during the movement of the composite desulfurizing agent. Furthermore, CaF2 can melt together with the Al-Mg-CaO-CaC2 mixture in molten iron and catalyze the desulfurization reaction of magnesium, thus contributing to improved desulfurization efficiency of the composite desulfurizing agent.

[0017] In one specific feasible implementation, the composite desulfurizing agent is prepared according to the following steps:

[0018] Granulation: The Al-Mg-CaO-CaC2 mixture is crushed and sieved to obtain mixed particles with a particle size of 0.5-2.5 mm; Coating: Calcium hydroxide is dissolved in hydrofluoric acid to obtain a solution. The mixed particles are added to the solution, and the solution is concentrated under stirring to obtain a colloidal precipitate. Then, stirring is stopped, the solution is removed by heating, and a block is obtained.

[0019] Post-processing: The lumps are crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0020] By adopting the above technical solution, since the concentration is carried out under stirring, the precipitated CaF2 adheres to the surface of the mixture particles, which helps to improve the uniformity of CaF2 on the surface of each mixture particle. After the formation of a colloidal precipitate, the solution is removed to obtain a block formed by CaF2 coating the mixture particles. Then, it is crushed and sieved to obtain the required composite desulfurizing agent.

[0021] In one specific implementation, the weight ratio of the calcium hydroxide and Al-Mg-CaO-CaC2 mixture particles is 1:(20-35).

[0022] By adopting the above technical solution, within the above weight ratio range, CaF2 can form an outer layer of suitable thickness on the surface of the Al-Mg-CaO-CaC2 mixture, thereby giving the composite desulfurizer good moisture-proof and friction-resistant properties. Moreover, at this ratio, CaF2 can exert excellent catalytic desulfurization effect, which helps the composite desulfurizer to perform desulfurization better.

[0023] In one specific implementation scheme, the outer skin is a steel pipe with an outer diameter of 8-13 mm, and the ratio of the particle size of the nickel-magnesium spheroidizing agent, the particle size of the composite desulfurizing agent, and the outer diameter of the outer skin is 1:(1-3):(8-13).

[0024] By adopting the above technical solution, the ratio between the particle size of the spheroidizing agent, the particle size of the desulfurizing agent, and the outer diameter of the outer sheath has a significant impact on the amount of magnesium added per unit time in the cored wire in molten iron. Through experiments, this application found that under the above ratio, the vapor pressure of magnesium can be reduced, the interaction time between magnesium and molten iron can be prolonged, and the utilization rate of magnesium can be improved.

[0025] In one specific implementation, the nickel-magnesium spheroidizing agent contains 15-18% magnesium by weight, with the balance being nickel.

[0026] By adopting the above technical solution, when the composition ratio of the Al-Mg-CaO-CaC2 mixture and the ratio of nickel-magnesium spheroidizing agent to composite desulfurizer are within the above range, using a nickel-magnesium spheroidizing agent with a magnesium weight percentage of 15-18% helps to further improve the spheroidizing effect of the cored wire.

[0027] Secondly, this application provides a method for preparing nickel-magnesium spheroidizing agent cored wire, which adopts the following technical solution:

[0028] A method for preparing a nickel-magnesium spheroidizing agent cored wire includes the following steps:

[0029] According to the formula, the nickel-magnesium spheroidizing agent and the composite desulfurizing agent are mixed evenly to obtain the core agent;

[0030] The core agent is wrapped around a steel strip using a core-coating machine, and the steel strip forms an outer sheath, thus obtaining a nickel-magnesium spheroidizing agent cored wire.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. This application uses a composite desulfurizing agent containing a mixture of Al-Mg-CaO-CaC2 and controls the ratio of each component within a certain range to prepare a cored wire that not only has excellent desulfurization effect and can reduce the loss of Mg in the nickel-magnesium spheroidizing agent, but also has better spheroidizing effect.

[0033] 2. The composite desulfurizer of this application forms a CaF2 layer on the outside of the Al-Mg-CaO-CaC2 mixture, which can reduce the moisture absorption of the Al-Mg-CaO-CaC2 mixture during storage, reduce the wear of the Al-Mg-CaO-CaC2 mixture during the movement of the composite desulfurizer, and catalyze the desulfurization reaction of magnesium, thus helping to improve the desulfurization effect of the composite desulfurizer.

[0034] 3. By controlling the ratio of the particle size of the nickel-magnesium spheroidizing agent, the particle size of the composite desulfurizing agent, and the outer diameter of the outer skin within the range of 1:(1-3):(8-13), this application can reduce the vapor pressure of magnesium, prolong the reaction time between magnesium and molten iron, and improve the utilization rate of magnesium. Detailed Implementation

[0035] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0036] Example

[0037] Example 1

[0038] This embodiment provides a nickel-magnesium spheroidizing agent cored wire, comprising an outer sheath and a core agent. The outer sheath is in the shape of a steel tube, and the core agent is encased within the outer sheath. The core agent comprises the following components by weight: 98 kg of nickel-magnesium spheroidizing agent and 2 kg of composite desulfurizing agent. The nickel-magnesium spheroidizing agent contains 16% magnesium by weight, with the balance being nickel, and the particle size of the nickel-magnesium spheroidizing agent is 1-3 mm. The composite desulfurizing agent is an Al-Mg-CaO-CaC2 mixture, with a particle size of 1-3 mm, and the outer sheath is a steel tube with an outer diameter of 13 mm.

[0039] The Al-Mg-CaO-CaC2 mixture of this embodiment uses the following components by weight: 21 kg of CaO, 11 kg of CaC2, 55 kg of Mg and 17 kg of Al.

[0040] The composite desulfurizing agent in this embodiment is prepared according to the following steps:

[0041] According to the formula, Al and Mg are added to the furnace and melted at 750°C. After being mixed until homogeneous, Al-Mg melt is obtained.

[0042] Next, place the CaO and CaC2 powders in a vacuum heating furnace, heat them to 800-1200℃, maintain the temperature for 2-4 minutes, then add them to the Al-Mg melt, stir until uniform, pour them into a mold, and cool them to room temperature to obtain an Al-Mg-CaO-CaC2 mixture.

[0043] The Al-Mg-CaO-CaC2 mixture was crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0044] This embodiment provides a method for preparing nickel-magnesium spheroidizing agent cored wire, which includes the following steps:

[0045] According to the formula, the nickel-magnesium spheroidizing agent and the composite desulfurizing agent are mixed evenly to obtain the core agent.

[0046] The core agent is filled into the steel strip using a cored wire forming machine, and the machine is operated to wrap the steel strip with the core agent, forming a cylindrical outer sheath with an outer diameter of 13mm, thus obtaining a nickel-magnesium spheroidizing agent cored wire.

[0047] Example 2

[0048] The only difference between this embodiment and Embodiment 1 is that the core agent uses the following components by weight: 99 kg of nickel-magnesium spheroidizing agent and 1 kg of composite desulfurizing agent.

[0049] Example 3

[0050] The only difference between this embodiment and Embodiment 1 is that the core agent uses the following components by weight: 98.5 kg of nickel-magnesium spheroidizing agent and 1.5 kg of composite desulfurizing agent.

[0051] Example 4

[0052] The only difference between this embodiment and Example 1 is that the magnesium weight percentage in the nickel-magnesium spheroidizing agent is 15%, with the balance being nickel.

[0053] Example 5

[0054] The only difference between this embodiment and Example 1 is that the magnesium weight percentage in the nickel-magnesium spheroidizing agent is 18%, with the balance being nickel.

[0055] Example 6

[0056] The only difference between this embodiment and Example 1 is that the magnesium weight percentage in the nickel-magnesium spheroidizing agent is 14%, with the balance being nickel.

[0057] Example 7

[0058] The only difference between this embodiment and Example 1 is that the magnesium weight percentage in the nickel-magnesium spheroidizing agent is 20%, with the balance being nickel.

[0059] Example 8

[0060] The only difference between this embodiment and Example 1 is that the Al-Mg-CaO-CaC2 mixture uses the following components by weight: 18 kg of CaO, 15 kg of CaC2, 50 kg of Mg and 17 kg of Al.

[0061] Example 9

[0062] The only difference between this embodiment and Example 1 is that the Al-Mg-CaO-CaC2 mixture uses the following components by weight: 24 kg of CaO, 8 kg of CaC2, 50 kg of Mg and 18 kg of Al.

[0063] Example 10

[0064] The only difference between this embodiment and Example 1 is that the Al-Mg-CaO-CaC2 mixture uses the following components by weight: 20 kg of CaO, 8 kg of CaC2, 50 kg of Mg and 22 kg of Al.

[0065] Example 11

[0066] The only difference between this embodiment and Example 1 is that the Al-Mg-CaO-CaC2 mixture uses the following components by weight: 20 kg of CaO, 8 kg of CaC2, 60 kg of Mg, and 12 kg of Al.

[0067] Example 12

[0068] The only difference between this embodiment and Embodiment 1 is that the composite desulfurizing agent includes an Al-Mg-CaO-CaC2 mixture and CaF2. CaF2 coats the outer surface of the Al-Mg-CaO-CaC2 mixture and forms a CaF2 layer.

[0069] The composite desulfurizing agent in this embodiment is prepared according to the following steps:

[0070] The Al-Mg-CaO-CaC2 mixture in this embodiment uses the following weight composition: 21 kg CaO, 11 kg CaC2, 55 kg Mg, and 17 kg Al. According to the formula, Al and Mg are added to a furnace and melted at 750°C. The mixture is then stirred until homogeneous to obtain an Al-Mg melt.

[0071] Next, place the CaO and CaC2 powders in a vacuum heating furnace, heat to 800-1200℃, maintain for 2-4 minutes, then add to the Al-Mg melt, stir until uniform, pour into a mold, and cool to room temperature to obtain an Al-Mg-CaO-CaC2 mixture.

[0072] The Al-Mg-CaO-CaC2 mixture was then crushed and sieved to obtain mixed particles with a particle size of 0.5-2.5 mm.

[0073] Then, calcium hydroxide was fully dissolved in hydrofluoric acid to obtain a solution. The mixed particles were then added to the solution, and the solution was concentrated under reduced pressure while stirring. After forming a colloidal precipitate, stirring was stopped, and the solution was further concentrated to remove it. After drying, a block was obtained. The weight ratio of calcium hydroxide to Al-Mg-CaO-CaC2 mixed particles was 1:28.

[0074] The lumps are then crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0075] Example 13

[0076] The only difference between this embodiment and Embodiment 1 is that the composite desulfurizing agent includes an Al-Mg-CaO-CaC2 mixture and CaF2. CaF2 coats the outer surface of the Al-Mg-CaO-CaC2 mixture and forms a CaF2 layer.

[0077] The composite desulfurizing agent in this embodiment is prepared according to the following steps:

[0078] The Al-Mg-CaO-CaC2 mixture in this embodiment uses the following weight composition: 21 kg CaO, 11 kg CaC2, 55 kg Mg, and 17 kg Al. According to the formula, Al and Mg are added to a furnace and melted at 750°C. The mixture is then stirred until homogeneous to obtain an Al-Mg melt.

[0079] Next, place the CaO and CaC2 powders in a vacuum heating furnace, heat to 800-1200℃, maintain for 2-4 minutes, then add to the Al-Mg melt, stir until uniform, pour into a mold, and cool to room temperature to obtain an Al-Mg-CaO-CaC2 mixture.

[0080] The Al-Mg-CaO-CaC2 mixture was then crushed and sieved to obtain mixed particles with a particle size of 0.5-2.5 mm.

[0081] Then, calcium hydroxide was fully dissolved in hydrofluoric acid to obtain a solution. The mixed particles were then added to the solution, and the solution was concentrated under reduced pressure while stirring. After forming a colloidal precipitate, stirring was stopped, and the solution was further concentrated to remove it. After drying, a block was obtained. The weight ratio of calcium hydroxide to Al-Mg-CaO-CaC2 mixed particles was 1:20.

[0082] The lumps are then crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0083] Example 14

[0084] The only difference between this embodiment and Embodiment 1 is that the composite desulfurizing agent includes an Al-Mg-CaO-CaC2 mixture and CaF2. CaF2 coats the outer surface of the Al-Mg-CaO-CaC2 mixture and forms a CaF2 layer.

[0085] The composite desulfurizing agent in this embodiment is prepared according to the following steps:

[0086] The Al-Mg-CaO-CaC2 mixture in this embodiment uses the following weight composition: 21 kg CaO, 11 kg CaC2, 55 kg Mg, and 17 kg Al. According to the formula, Al and Mg are added to a furnace and melted at 750°C. The mixture is then stirred until homogeneous to obtain an Al-Mg melt.

[0087] Next, place the CaO and CaC2 powders in a vacuum heating furnace, heat to 800-1200℃, maintain for 2-4 minutes, then add to the Al-Mg melt, stir until uniform, pour into a mold, and cool to room temperature to obtain an Al-Mg-CaO-CaC2 mixture.

[0088] The Al-Mg-CaO-CaC2 mixture was then crushed and sieved to obtain mixed particles with a particle size of 0.5-2.5 mm.

[0089] Then, calcium hydroxide was fully dissolved in hydrofluoric acid to obtain a solution. The mixed particles were then added to the solution, and the solution was concentrated under reduced pressure while stirring. After forming a colloidal precipitate, stirring was stopped, and the solution was further concentrated to remove it. After drying, a block was obtained. The weight ratio of calcium hydroxide to Al-Mg-CaO-CaC2 mixed particles was 1:35.

[0090] The lumps are then crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0091] Example 15

[0092] The only difference between this embodiment and Embodiment 1 is that the outer skin is a steel pipe with an outer diameter of 10mm.

[0093] Example 16

[0094] The only difference between this embodiment and Embodiment 1 is that the outer casing is a steel pipe with an outer diameter of 8mm.

[0095] Comparative Example

[0096] Comparative Example 1

[0097] This comparative example provides a nickel-magnesium spheroidizing agent cored wire. The only difference between this comparative example and Example 1 is that the composite desulfurizing agent is a Mg-CaO-CaC2 mixture. The Mg-CaO-CaC2 mixture uses the following weight components: 21 kg of CaO, 11 kg of CaC2, and 72 kg of Mg.

[0098] The composite desulfurizing agent of this comparative example was prepared according to the following steps:

[0099] According to the formula, Mg is added to the furnace and melted at 750°C to form Mg molten material.

[0100] Next, place the CaO and CaC2 powders in a vacuum heating furnace, heat them to 800-1200℃, maintain the temperature for 2-4 minutes, then add them to the molten Mg, stir until uniform, pour them into a mold, and cool them to room temperature to obtain a Mg-CaO-CaC2 mixture.

[0101] The Mg-CaO-CaC2 mixture was crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0102] Comparative Example 2

[0103] This comparative example provides a nickel-magnesium spheroidizing agent cored wire. The only difference between this comparative example and Example 1 is that the composite desulfurizer is an Al-Mg-CaO mixture. The Al-Mg-CaO mixture uses the following weight components: 32 kg of CaO, 55 kg of Mg and 17 kg of Al.

[0104] The composite desulfurizing agent of this comparative example was prepared according to the following steps:

[0105] According to the formula, Al and Mg are added to the furnace and melted at 750°C. After being mixed until homogeneous, Al-Mg melt is obtained.

[0106] Next, place the CaO powder in a vacuum heating furnace, heat it to 800-1200℃, maintain it for 2-4 minutes, then add it to the molten Mg, stir until uniform, then pour it into a mold, and cool it to room temperature to obtain an Al-Mg-CaO mixture.

[0107] The Al-Mg-CaO mixture is crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0108] Comparative Example 3

[0109] This comparative example provides a nickel-magnesium spheroidizing agent cored wire. The only difference between this comparative example and Example 1 is that the composite desulfurizing agent is an Al-Mg-CaC2 mixture. The Al-Mg-CaC2 mixture uses the following weight components: 32 kg of CaC2, 55 kg of Mg and 17 kg of Al.

[0110] The composite desulfurizing agent of this comparative example was prepared according to the following steps:

[0111] According to the formula, Al and Mg are added to the furnace and melted at 750°C. After being mixed until homogeneous, Al-Mg melt is obtained.

[0112] Next, place the CaC2 powder in a vacuum heating furnace, heat it to 800-1200℃, maintain it for 2-4 minutes, then add it to the molten Mg, stir until uniform, then pour it into a mold, and cool it to room temperature to obtain an Al-Mg-CaC2 mixture.

[0113] The Al-Mg-CaC2 mixture was crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

[0114] Comparative Example 4

[0115] This comparative example provides a nickel-magnesium spheroidizing agent cored wire. The only difference between this comparative example and Example 1 is that the core agent uses the following components by weight: 97 kg of nickel-magnesium spheroidizing agent and 3 kg of composite desulfurizer.

[0116] Comparative Example 5

[0117] This comparative example provides a nickel-magnesium spheroidizing agent cored wire. The only difference between this comparative example and Example 1 is that the core agent uses the following components by weight: 99.5 kg of nickel-magnesium spheroidizing agent and 0.5 kg of composite desulfurizer.

[0118] Performance testing

[0119] The nickel-magnesium spheroidizing agent cored wires provided in Examples 1-16 and Comparative Examples 1-5 were used in the production of ductile iron. The process conditions for the production of ductile iron in each group were kept the same, and the ductile iron produced was tested. The spheroidization rate and strength of the ductile iron were tested according to GB1348-2009. The test results are shown in Table 1.

[0120] Table 1

[0121]

[0122] As can be seen from Example 1 and Comparative Examples 1-5, and Table 1, the spheroidization rate or strength of Comparative Examples 1-5 is lower than that of Example 1. This indicates that the raw material ratio and preparation conditions of Example 1 are more conducive to improving the spheroidization effect of nickel-magnesium spheroidizing agent cored wire.

[0123] As can be seen from Examples 1-16 and Table 1, the nickel-magnesium spheroidizing agent cored wires prepared in Examples 1-16 all exhibit good spheroidizing effects. This indicates that within the range of raw material ratios and process conditions in Examples 1-16, it is helpful to improve the spheroidizing effect of the nickel-magnesium spheroidizing agent cored wires. Therefore, it can be demonstrated that the core agent prepared using the nickel-magnesium spheroidizing agent and composite desulfurizing agent of this application and their ratios can improve the spheroidizing effect of nickel-magnesium spheroidizing agent cored wires.

[0124] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A nickel-magnesium spheroidizing agent cored wire, characterized in that: The product includes an outer skin and a core agent encased within the outer skin. Based on the total weight of the core agent, the core agent comprises the following components in parts by weight: 98-99 parts of nickel-magnesium spheroidizing agent and 1-2 parts of composite desulfurizing agent. The composite desulfurizing agent comprises an Al-Mg-CaO-CaC2 mixture. Based on the total weight of the Al-Mg-CaO-CaC2 mixture, the Al-Mg-CaO-CaC2 mixture comprises the following components in parts by weight: 18-24 parts CaO, 8-15 parts CaC2, 50-60 parts Mg, and 12-22 parts Al. The Al-Mg-CaO-CaC2 mixture was prepared according to the following steps: Melting: Al and Mg are melted and mixed to obtain an Al-Mg melt; Preparation of the mixture: CaO and CaC2 are heated to 800-1200℃ under vacuum, then added to the Al-Mg melt, stirred until homogeneous, and then cooled to room temperature to obtain the Al-Mg-CaO-CaC2 mixture.

2. The nickel-magnesium spheroidizing agent cored wire according to claim 1, characterized in that, The composite desulfurizing agent also includes CaF2, which forms an outer layer encapsulating the Al-Mg-CaO-CaC2 mixture.

3. The nickel-magnesium spheroidizing agent cored wire according to claim 2, characterized in that, The composite desulfurizing agent is prepared according to the following steps: Granulation: The Al-Mg-CaO-CaC2 mixture is crushed and sieved to obtain mixed particles with a particle size of 0.5-2.5 mm; Packaging: After dissolving calcium hydroxide in hydrofluoric acid to obtain a solution, add the mixed particles to the solution, concentrate the solution while stirring to obtain a colloidal precipitate, then stop stirring, heat to remove the solution, and obtain a block; Post-processing: The lumps are crushed and sieved to obtain a composite desulfurizing agent with a particle size of 1-3 mm.

4. The nickel-magnesium spheroidizing agent cored wire according to claim 3, characterized in that: In the encapsulation step, the weight ratio of the calcium hydroxide and Al-Mg-CaO-CaC2 mixture particles is 1:(20-35).

5. The nickel-magnesium spheroidizing agent cored wire according to claim 1, characterized in that: The outer skin is a steel pipe with an outer diameter of 8-13 mm, and the ratio of the particle size of the nickel-magnesium spheroidizing agent, the particle size of the composite desulfurizing agent and the outer diameter of the outer skin is 1:(1-3):(8-13).

6. The nickel-magnesium spheroidizing agent cored wire according to claim 1, characterized in that: The nickel-magnesium spheroidizing agent contains 15-18% magnesium by weight, with the balance being nickel.

7. A method for preparing a nickel-magnesium spheroidizing agent cored wire as described in any one of claims 1-6, characterized in that, Includes the following steps: According to the formula, the nickel-magnesium spheroidizing agent and the composite desulfurizing agent are mixed evenly to obtain the core agent; The core agent is wrapped around a steel strip using a core-coating machine, and the steel strip forms an outer sheath, thus obtaining a nickel-magnesium spheroidizing agent cored wire.

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