A material to prevent bridging of feeders in a vacuum induction furnace

Abstract

This invention relates to the field of metallurgy, specifically to a material for preventing bridging during vacuum induction furnace charging. It mainly comprises Ni, Mo, and Fe, and its application method is as follows: S1, repairing the furnace; S2, pre-treating the material and alloy blocks for preventing bridging during vacuum induction furnace charging; S3, pouring the alloy blocks with the molten material for preventing bridging during vacuum induction furnace charging to form a furnace charge assembly; S4, removing the furnace charge assembly from the cooling template and placing it into the vacuum induction furnace, evacuating the vacuum, heating to melt and refine it, and then casting it into shape. This invention connects multiple alloy blocks by casting the molten material for preventing bridging during vacuum induction furnace charging, making them a unified whole. When the material is fed into the induction furnace from above using a charging hopper, it will not scatter. Because it enters the furnace as a whole, its surface can be controlled to not contact the furnace wall, allowing for more stable downward melting and significantly reducing bridging.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and specifically to a material for preventing bridging during the feeding of a vacuum induction furnace. Background Technology

[0002] A vacuum induction melting furnace is a device that uses electromagnetic induction to generate eddy currents within a metal conductor to heat and melt the furnace charge under vacuum conditions. In traditional melting processes, after the charge is fed into the furnace, the scattered alloy blocks easily come into contact with the furnace wall, posing a risk of bridging. This is because the carbon-oxygen reaction is intense under vacuum conditions, and the molten steel often splashes violently. The splashed molten steel can bind the upper charge and the furnace charge with the residue on the inner wall of the crucible, causing the upper charge to be suspended and unable to descend, while the lower charge is completely melted into molten steel, forming a molten pool. The unmelted upper charge and the lower molten steel completely separate, ultimately leading to bridging.

[0003] The following methods can be used to break up bridging: ① break it open with a hammer; ② tilt the crucible and use molten steel to heat open the bridging area; ③ for severe bridging, vacuum treatment can be performed. Of course, fundamentally reducing bridging in vacuum induction melting furnaces is the preferred way to improve smelting efficiency and reduce energy costs. Therefore, we propose a material to prevent bridging during charging in vacuum induction furnaces. Summary of the Invention

[0004] (i) In view of the shortcomings of the prior art, the present invention provides a material to prevent bridging during the feeding of vacuum induction furnace, which overcomes the problem of bridging that easily occurs in the smelting process of vacuum induction furnace in the prior art. The casting connection is integrated into a whole, which can melt downwards more stably and greatly reduce the phenomenon of bridging.

[0005] (II) To achieve the above objectives, the present invention is implemented through the following technical solution: a material for preventing bridging during the feeding of a vacuum induction furnace, comprising the following components by mass percentage: Ni 10-20%, Mo 0.5-3%, S≤0.05%, P≤0.05%, with the balance being Fe.

[0006] This invention provides a method for preparing a material to prevent bridging during the feeding of a vacuum induction furnace, comprising the following steps:

[0007] (1) The raw materials are put into the furnace in proportion and heated and melted under vacuum. At the same time, carbon particles are added for deoxidation treatment to obtain molten liquid;

[0008] (2) After filtering the molten liquid, it is poured, cooled and shaped to obtain the material that prevents bridging during the feeding of the vacuum induction furnace.

[0009] Preferably, in step (1), the vacuum degree is controlled to be 1-10 Pa and the furnace temperature is 1500-1600℃.

[0010] Preferably, in step (1), the size of the carbon particles is 5-10 mm, and the carbon particles are dried at 60-80°C for 20-30 min to remove moisture before being added to the furnace.

[0011] The present invention also provides a method for applying materials to prevent bridging during the feeding of a vacuum induction furnace, comprising the following steps:

[0012] S1. Inspect the inner wall of the furnace before loading, and repair any pits or cracks on it.

[0013] S2. Pre-treat the material and alloy block that prevent bridging during the vacuum induction furnace feeding process to remove rust and oil stains, and obtain the pre-treated material and pre-treated alloy block that prevent bridging during the vacuum induction furnace feeding process.

[0014] S3. Arrange the pretreated alloy blocks neatly on the cooling template, leaving gaps between the alloy blocks. Melt the pretreated material to prevent bridging during vacuum induction furnace charging and pour it into the gaps. After cooling and shaping, a furnace charge bond is formed.

[0015] S4. Remove the furnace charge assembly from the cooling template and put it into a vacuum induction furnace. After vacuuming, heat up to melt and refine it, and then cast it into shape.

[0016] Preferably, in step S2, the pretreatment process is as follows: the surface of the pretreatment material to prevent bridging in the vacuum induction furnace and the pretreatment alloy block are polished, then cleaned with an ethanol solution, rinsed with water, and finally dried. The ethanol solution has a mass fraction of 40%; the drying temperature is 80-90℃, and the drying time is 30-50 minutes.

[0017] Preferably, in step S3, the gap between the alloy blocks is controlled between 1-5 mm.

[0018] Preferably, in step S4, the vacuum degree is controlled at 4-5 Pa, and the temperature is raised to 1500-1580℃.

[0019] Preferably, in step S4, the melting rate of the furnace charge assembly is 2-3 kg / min.

[0020] (III) This invention provides a material to prevent bridging during the feeding of a vacuum induction furnace, which has the following beneficial effects:

[0021] This invention connects multiple gold ingots by casting a molten material that prevents bridging during vacuum induction furnace charging, thus forming a unified whole. After being fed into the induction furnace by a charging hopper, the ingots do not scatter. Because they enter the furnace as a whole, their outer surface can be controlled to avoid contact with the furnace wall, allowing for more stable downward melting and significantly reducing bridging. Furthermore, the material used to prevent bridging during vacuum induction furnace charging is composed of Ni, Mo, and Fe, which does not affect the composition of the molten steel.

[0022] This invention deoxidizes the material used to prevent bridging during charging in a vacuum induction furnace by adding carbon particles, thereby reducing its oxygen content. This reduces the overall oxygen content of the molten steel, limits the carbon-oxygen reaction, reduces molten steel splashing, and to some extent reduces the bridging problem. Attached Figure Description

[0023] Figure 1 This is a bar chart showing the melting rate versus the bridging ratio.

[0024] Among them, the method of Comparative Example 1 was used, and multiple sets of experiments were conducted with melting rate as the controlled variable. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0026] Example 1

[0027] A method for preparing a material to prevent bridging during the feeding of a vacuum induction furnace, specifically including the following steps:

[0028] (1) The raw materials are put into the furnace in proportion and heated and melted under vacuum. The vacuum degree is controlled at 2Pa ​​and the furnace temperature is 1500℃. At the same time, carbon particles are added for deoxidation treatment. The size of the carbon particles is 5mm. Before adding the carbon particles to the furnace, they are dried at 60℃ for 20min to remove moisture and obtain molten liquid.

[0029] (2) After filtering the molten liquid, it is poured, cooled and shaped to obtain the material that prevents bridging during the feeding of the vacuum induction furnace.

[0030] The material used to prevent bridging of the vacuum induction furnace feeder, by weight percentage, comprises the following components: Ni 10%, Mo 3%, S≤0.05%, P≤0.05%, with the balance being Fe.

[0031] Example 2

[0032] A method for preparing a material to prevent bridging during the feeding of a vacuum induction furnace, specifically including the following steps:

[0033] (1) The raw materials are put into the furnace in proportion and heated and melted under vacuum. The vacuum degree is controlled at 10 Pa and the furnace temperature is 1600℃. At the same time, carbon particles are added for deoxidation treatment. The size of the carbon particles is 10 mm. Before adding the carbon particles to the furnace, they are dried at 80℃ for 30 min to remove moisture and obtain molten liquid.

[0034] (2) After filtering the molten liquid, it is poured, cooled and shaped to obtain the material that prevents bridging during the feeding of the vacuum induction furnace.

[0035] The material used to prevent bridging of the vacuum induction furnace feeder, by weight percentage, comprises the following components: Ni 20%, Mo 0.5%, S≤0.05%, P≤0.05%, with the balance being Fe.

[0036] Example 3

[0037] A method for applying a material to prevent bridging during the feeding of a vacuum induction furnace includes the following steps:

[0038] S1. Inspect the inner wall of the furnace before loading, and repair any pits or cracks on it.

[0039] S2. Pre-treat the material and alloy block that prevent bridging during the vacuum induction furnace feeding process to remove rust and oil stains, and obtain the pre-treated material and pre-treated alloy block that prevent bridging during the vacuum induction furnace feeding process.

[0040] S3. Arrange the pretreated alloy blocks neatly on the cooling template, leaving a 2mm gap between the alloy blocks. Melt the pretreated material to prevent bridging during vacuum induction furnace charging and pour it into the gap. After cooling and shaping, a furnace charge bond is formed.

[0041] S4. Remove the furnace charge assembly from the cooling template and place it into a vacuum induction furnace. Control the vacuum level to 4 Pa, raise the temperature to 1500℃ for melting and refining, and then cast it into shape. The melting rate of the furnace charge assembly is 2 kg / min.

[0042] In step S2, the pretreatment process is as follows: the surface of the pretreatment material to prevent bridging in the vacuum induction furnace and the pretreatment alloy block are polished, then cleaned with 40wt% ethanol solution, then rinsed with water, and finally dried at 80℃ for 30min.

[0043] In this embodiment, the material used in Embodiment 1 to prevent bridging during the feeding of the vacuum induction furnace is employed.

[0044] Example 4

[0045] A method for applying a material to prevent bridging during the feeding of a vacuum induction furnace includes the following steps:

[0046] S1. Inspect the inner wall of the furnace before loading, and repair any pits or cracks on it.

[0047] S2. Pre-treat the material and alloy block that prevent bridging during the vacuum induction furnace feeding process to remove rust and oil stains, and obtain the pre-treated material and pre-treated alloy block that prevent bridging during the vacuum induction furnace feeding process.

[0048] S3. Arrange the pretreated alloy blocks neatly on the cooling template, leaving a 4mm gap between the alloy blocks. Melt the pretreated material to prevent bridging during vacuum induction furnace charging and pour it into the gap. After cooling and shaping, a furnace charge bond is formed.

[0049] S4. Remove the furnace charge assembly from the cooling template and place it into a vacuum induction furnace. Control the vacuum level to 5 Pa, raise the temperature to 1580℃ for melting and refining, and then cast it into shape. The melting rate of the furnace charge assembly is 3 kg / min.

[0050] In step S2, the pretreatment process is as follows: the surface of the pretreatment material to prevent bridging in the vacuum induction furnace and the pretreatment alloy block are polished, then cleaned with 40wt% ethanol solution, then rinsed with water, and finally dried at 90℃ for 50min.

[0051] In this embodiment, the material used in Embodiment 2 to prevent bridging during the feeding of the vacuum induction furnace is employed.

[0052] Comparative Example 1

[0053] A method for preventing bridging during the feeding of a vacuum induction furnace includes the following steps:

[0054] S1. Inspect the inner wall of the furnace before loading, and repair any pits or cracks on it.

[0055] S2. Pre-treat the alloy block to remove rust and oil stains, and obtain a pre-treated alloy block.

[0056] S3. The pretreated alloy block is placed into a vacuum induction furnace, the vacuum degree is controlled at 5 Pa, and the temperature is raised to 1580℃ for melting and refining, and then cast into shape. The melting rate of the furnace charge is 3 kg / min.

[0057] In step S2, the pretreatment process is as follows: the surface of the pretreated alloy block is polished, then cleaned with 40wt% ethanol solution, then rinsed with water, and finally dried at 90℃ for 50min.

[0058] Comparative Example 2

[0059] A method for preventing bridging during the feeding of a vacuum induction furnace includes the following steps:

[0060] S1. Inspect the inner wall of the furnace before loading, and repair any pits or cracks on it.

[0061] S2. Pre-treat the alloy block to remove rust and oil stains, and obtain a pre-treated alloy block.

[0062] S3. The pretreated alloy block is placed into a vacuum induction furnace, the vacuum degree is controlled at 5 Pa, and it is melted and refined at high temperature, and then cast into shape. The melting rate of the furnace charge is 4 kg / min.

[0063] In step S2, the pretreatment process is as follows: the surface of the pretreated alloy block is polished, then cleaned with 40wt% ethanol solution, then rinsed with water, and finally dried at 90℃ for 50min.

[0064] Comparative Example 3

[0065] The method is basically the same as in Example 4, except that the preparation method of the material to prevent bridging during the vacuum induction furnace feeding is as follows:

[0066] (1) The raw materials are placed in a furnace according to the proportion and heated and melted under vacuum. The vacuum degree is controlled at 10 Pa and the furnace temperature is 1600℃ to obtain the molten liquid.

[0067] (2) After filtering the molten liquid, it is poured, cooled and shaped to obtain the material that prevents bridging during the feeding of the vacuum induction furnace.

[0068] The material used to prevent bridging of the vacuum induction furnace feeder, by weight percentage, comprises the following components: Ni 20%, Mo 0.5%, S≤0.05%, P≤0.05%, with the balance being Fe.

[0069] Implementation effect

[0070] 1. A 50kg vacuum induction furnace was used for experimental steelmaking, and the measures in Examples 3-4 and Comparative Examples 1-3 were implemented multiple times. The specific results are shown in the table below.

[0071] Table 1. Bridge Construction Ratio

[0072] Group Bridge construction rate (%) Example 3 2.3 Example 4 3.5 Comparative Example 1 20.4 Comparative Example 2 35.8 Comparative Example 3 5.2

[0073] As can be seen from the table above:

[0074] a. When smelting using the measures in Examples 3-4, the bridging ratio of the vacuum induction furnace is significantly reduced compared to Comparative Example 1. This indicates that by using materials that prevent bridging during vacuum induction furnace charging, multiple gold blocks are connected to form a whole. During the smelting process, the upper furnace charge is difficult to disperse, thus reducing the occurrence of bridging.

[0075] b. Using the measures in Comparative Example 2, the bridging ratio is higher than that in Comparative Example 1, indicating that the melting rate is too fast, the carbon-oxygen reaction is fast, the CO gas is generated more quickly, and the boiling and splashing of the molten steel is more likely to cause bridging.

[0076] c. Using the measures in Comparative Example 3, the bridging ratio is slightly lower than that in Examples 3 or 4, indicating that after the material for preventing bridging during vacuum induction furnace feeding is deoxidized, the reduction in oxygen content limits the carbon-oxygen reaction, thereby reducing the occurrence of bridging to a certain extent.

[0077] from Figure 1 As can be seen from the data, in the traditional method of direct alloy addition, controlling the melting rate between 2-3 kg / min can keep the bridging ratio in a low range. When the melting rate exceeds 3 kg / min, the splashing phenomenon becomes severe, and the possibility of bridging increases. When the melting rate is below 2 kg / min, the energy consumption is relatively high.

[0078] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for applying a material to prevent bridging during the feeding of a vacuum induction furnace, characterized in that, The material, by mass percentage, comprises the following components: Ni 10-20%, Mo 0.5-3%, S ≤0.05%, P ≤0.05%, with the balance being Fe. The method includes the following steps: S1. Inspect the inner wall of the furnace before loading, and repair any pits or cracks on it. S2. Pre-treat the material and alloy block that prevent bridging during the vacuum induction furnace feeding process to remove rust and oil stains, and obtain the pre-treated material and pre-treated alloy block that prevent bridging during the vacuum induction furnace feeding process. S3. Arrange the pretreated alloy blocks neatly on the cooling template, leaving gaps between the alloy blocks. Melt the pretreated material to prevent bridging during vacuum induction furnace charging and pour it into the gaps. After cooling and shaping, a furnace charge bond is formed. S4. Remove the furnace charge assembly from the cooling template and put it into a vacuum induction furnace. After vacuuming, heat up to melt and refine it, and then cast it into shape.

2. The method for applying a material to prevent bridging during charging in a vacuum induction furnace as described in claim 1, characterized in that, In step S2, the pretreatment process is as follows: the surface of the pretreatment material to prevent bridging of the vacuum induction furnace and the pretreatment alloy block are polished, then cleaned with ethanol solution, then rinsed with water, and finally dried.

3. The method for applying a material to prevent bridging during charging in a vacuum induction furnace as described in claim 1, characterized in that, The ethanol solution has a mass fraction of 40%; the drying temperature is 80-90℃ and the drying time is 30-50 min.

4. The method for applying a material to prevent bridging during charging in a vacuum induction furnace as described in claim 1, characterized in that, In step S3, the gap between the alloy blocks is controlled between 1-5 mm.

5. The method for applying a material to prevent bridging during charging in a vacuum induction furnace as described in claim 1, characterized in that, In step S4, the vacuum level is controlled at 4-5 Pa, and the temperature is raised to 1500-1580℃.

6. The method for applying a material to prevent bridging during charging in a vacuum induction furnace as described in claim 1, characterized in that, In step S4, the melting rate of the furnace charge assembly is 2-3 kg / min.

Images