CN117047076A - Electromagnetic energy casting system for 20Kg vacuum smelting furnace - Google Patents

Abstract

The invention provides an electromagnetic energy casting system for a 20Kg vacuum melting furnace, which comprises the following components: the heating element is coated and arranged on the outer side of the metal mold; the metal mold is used for accommodating melt; an electromagnetic coil wound on the outer side of the heating element for heating the melt; and the pulse power supply is connected with the electromagnetic coil and used for controlling the electromagnetic coil to generate a magnetic field so as to control the melt to solidify. The invention can compensate the energy required by forming critical crystal nucleus in the melt through the pulse magnetic field generated by the electromagnetic coil, reduce the nuclear energy barrier, improve the nuclear rate, further promote the grain refinement, inhibit the grain growth, improve the performance of the finished product casting, simultaneously destroy the growth of columnar crystals, convert the columnar crystals into equiaxed crystals, improve the fine density of casting tissue, and be beneficial to reducing casting blank inclusion, bubbles, looseness, shrinkage cavity and the like.

Description

An electromagnetic energy casting system for 20Kg vacuum melting furnace

Technical field

The invention relates to the technical fields of metallurgy and metal material preparation, and in particular to an electromagnetic energy casting system for a 20Kg vacuum smelting furnace.

Background technique

Because nickel-based superalloys have sufficiently high heat resistance, good plasticity, resistance to high-temperature oxidation and gas corrosion, and long-term organizational stability, nickel-based superalloys are mainly used in the manufacture of hot-end components of turbine engines and aerospace rocket engines. high-temperature components. The commonly used production process for nickel-based alloys is vacuum induction furnace melting. Vacuum induction melting furnace is a device that uses electromagnetic induction to generate eddy currents in metal conductors under vacuum conditions to heat the charge for melting. Its working principle is that when the coil is connected to the AC power supply, an alternating magnetic field is generated in the middle of the coil, and an induced electric potential is generated in the charge. The metal charge itself forms a closed loop, so an induced current, that is, an eddy current, is generated in the charge at the same time. Vortex heating and melting. However, with the development of nickel-based casting high-temperature alloys, the degree of alloying continues to increase, and the solidification segregation of alloy elements becomes increasingly serious, which reduces the structural stability of the alloy and worsens the process performance, hindering the further development of nickel-based casting high-temperature alloys. The first way to improve the performance of deformed high-temperature alloy materials is to improve the purity and reduce the content of gases, ceramic inclusions and harmful elements in the high-temperature alloy; the second is to obtain a uniform and dense internal structure to eliminate or reduce the looseness, holes, and Metallurgical defects such as composition segregation.

The pulse magnetic field causes pulse eddy currents in the melt. The interaction between the eddy currents and the magnetic field produces Lorentz force and magnetic pressure. They change drastically and their intensity is much greater than the dynamic pressure of the metal melt. This causes the metal melt to produce Strong vibration. On the one hand, this vibration increases the degree of supercooling during the solidification of the melt and increases the nucleation rate; on the other hand, it causes forced convection in the melt, making it difficult for dendrites to grow or be broken or damaged during the solidification process. Broken, these broken dendrite particles become free in the liquid at the crystallization front and become new growth cores. Secondly, the magnetic energy generated by the pulse magnetic field directly acts on the core melt with a lower degree of supercooling, reducing the nucleation work required for crystallization of the solidified structure, achieving the effect of simultaneous crystallization of the edge and core structures.

Contents of the invention

In order to solve the above problems, the purpose of the present invention is to provide an electromagnetic energy casting system for a 20Kg vacuum melting furnace.

In order to achieve the above objects, the present invention provides the following solutions:

An electromagnetic energy casting system for a 20Kg vacuum melting furnace, including:

The heating element is wrapped and arranged on the outside of the metal mold; the metal mold is used to accommodate the melt;

An electromagnetic coil, wound around the outside of the heating element, is used to heat the melt;

A pulse power supply is connected to the electromagnetic coil and used to control the electromagnetic coil to generate a magnetic field to control the solidification of the melt.

Preferably, a heat insulation layer is provided between the heating element and the electromagnetic coil.

Preferably, the bottom of the metal mold is provided with an insulating pad.

Preferably, the inlet of the metal mold is provided with a pouring protection port.

Preferably, the heating element is covered with a shell, and the heating element and the metal mold are both arranged in the shell.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The present invention provides an electromagnetic energy casting system for a 20Kg vacuum melting furnace. Compared with the existing technology, the present invention can compensate for the energy required to form critical nucleation inside the melt through the pulse magnetic field generated by the electromagnetic coil and reduce the nucleation energy barrier. , improve the nucleation rate, thereby promoting grain refinement and inhibiting grain growth, improving the performance of finished castings, and destroying the growth of columnar crystals, converting columnar crystals into equiaxed crystals, improving the fineness of the casting structure, and is beneficial to Reduce billet inclusions, bubbles, porosity and shrinkage cavities.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the drawings of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of the electromagnetic energy casting system for a 20Kg vacuum melting furnace of the present invention;

Figure 2 is a top view of the electromagnetic energy casting system for the 20Kg vacuum melting furnace of the present invention;

Figure 3 is a two-dimensional plan sectional view of the electromagnetic energy casting system for a 20Kg vacuum melting furnace of the present invention;

Figure 4 is the current waveform diagram;

Figure 5 is a cloud diagram of the magnetic induction intensity distribution of the present invention;

Figure 6 is a vector diagram of the induced magnetic field in the melt of the present invention;

Figure 7 shows the magnetic field distribution at the center of the melt of the present invention.

Symbol Description:

1. Electromagnetic coil; 2. Heating element; 3. Melt; 4. Metal type; 5. Insulation pad; 6. Pouring protection port.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In order to achieve the above objects, the present invention provides the following solutions:

Please refer to Figure 1-7 together, an electromagnetic energy casting system for a 20Kg vacuum melting furnace, including: electromagnetic coil 1, heating element 2, melt 3, metal mold 4, thermal insulation pad 5 and pouring protection port 6.

The heating element 2 is wrapped and arranged on the outside of the metal mold 4; the metal mold 4 is used to accommodate the melt 3. In the present invention, the melt is a nickel-based alloy melt; the electromagnetic coil 1 is wound around the heating element The outside of 2 is used to heat the melt 3; the pulse power supply is connected to the electromagnetic coil 1 and is used to control the electromagnetic coil 1 to generate a magnetic field to control the solidification of the melt 3.

In practical applications, the heating element is an induction coil, and an alternating current is applied to it by a power supply to generate a magnetic field. Due to electromagnetic induction, an induced current is generated in the metal charge. When the induced current flows in the metal charge, heat is generated due to resistance. To heat and preserve the metal charge, the present invention uses an induction coil to preheat the metal mold and uses the induced eddy current inside the metal mold to generate Joule heat for heating. This method has the characteristics of uniform heating, good temperature compensation effect, and heating as needed.

Further, when the electromagnetic coil is working, the duty cycle of the electromagnetic energy is 20%-60%, the peak value of the electromagnetic energy output current is 100A-300A, the output frequency is 50Hz, and the central magnetic field strength of the nickel-based alloy in the metal type is greater than 35mT. .

When using the present invention, you first need to turn on the cooling water of the hollow copper coil, and then turn on the power supply of the heating element to start preheating the metal mold. After the pulse power supply starts working, eddy current is generated in the metal mold to preheat it. . After reaching the target preheating temperature, turn on the power of the pulse device, adjust the appropriate pulse power parameters for grain refinement, pour the metal melt, and perform electromagnetic pulse treatment on the metal melt until it is completely solidified.

The present invention can control the temperature by changing the current of the induction coil through an external power source, thereby controlling the cooling rate. In the actual crystallization process, the actual crystallization temperature is always lower than the theoretical crystallization temperature. This phenomenon is called supercooling, and the temperature difference between the two is called the degree of supercooling. The degree of subcooling is closely related to the cooling rate. The faster the cooling rate, the lower the actual crystallization temperature and the greater the degree of subcooling. On the contrary, the slower the cooling rate, the smaller the degree of subcooling and the actual crystallization temperature is closer to the theory. Crystallization temperature. As the cooling rate increases, the degree of undercooling will also increase. In the case of a larger degree of undercooling, the nucleation rate increases faster than the growth rate of the crystal nuclei, so that finer grains can be obtained. At the same time, the invention combined with the pulse magnetic field generated by the electromagnetic coil can compensate for the energy required to form critical crystal nuclei inside the melt, reduce the nucleation energy barrier, increase the nucleation rate, thereby promoting grain refinement and inhibiting grain growth, and improving the finished casting. It also destroys the growth of columnar crystals and transforms columnar crystals into equiaxed crystals, which improves the fineness of the casting structure and helps reduce inclusions, bubbles, porosity and shrinkage cavities in the casting slab.

Furthermore, a heat insulation layer is provided between the heating element 2 and the electromagnetic coil 1 . The bottom of the metal mold is provided with an insulating pad 5 . The entrance of the metal mold 4 is provided with a pouring protection port 6 .

In the embodiment of the present invention, the heating element 2 is covered with a shell, and the heating element 2 and the metal mold 4 are both arranged in the shell.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The present invention uses a method that combines pulse magnetic field and cooling rate control to process the alloy melt, which can cause obvious grain equiaxed transformation and grain refinement in the alloy microstructure, enhance the structural uniformity of the alloy, and effectively weaken the The anisotropy of the alloy can reduce casting defects including cracks, shrinkage cavities, shrinkage porosity, and pores.

This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and the core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the present invention There will be changes in the specific implementation methods and application scope of the ideas. In summary, the contents of this description should not be construed as limitations of the present invention.

Claims (5)

1. An electromagnetic energy casting system for a 20Kg vacuum melting furnace, comprising:

the heating element is coated and arranged on the outer side of the metal mold; the metal mold is used for accommodating melt;

an electromagnetic coil wound on the outer side of the heating element for heating the melt;

and the pulse power supply is connected with the electromagnetic coil and used for controlling the electromagnetic coil to generate a magnetic field so as to control the melt to solidify.

2. An electromagnetic energy casting system for a 20Kg vacuum melting furnace as claimed in claim 1 wherein a thermal insulating layer is provided between the heating element and the electromagnetic coil.

3. An electromagnetic energy casting system for a 20Kg vacuum melting furnace according to claim 1 wherein the bottom of the mold is provided with a heat insulating pad.

4. An electromagnetic energy casting system for a 20Kg vacuum melting furnace according to claim 1, wherein the inlet of the metal mold is provided with a casting protection port.

5. The electromagnetic energy casting system for a 20Kg vacuum melting furnace according to claim 1, wherein a housing is sleeved outside the heating element, and the heating element and the metal mold are both disposed in the housing.