Light alloy semi-continuous casting device and method under composite action of shear and magnetic field

Abstract

A light alloy semi-continuous casting device and method under the combined action of shearing and magnetic field, belonging to the technical field of light alloy semi-continuous casting. Compared with the existing technology, the present invention combines the use of magnetic field and melt shear on the basis of conventional semi-continuous casting. Its melt shear unit has the characteristics of strong shear and weak convection, which makes up for the weak shear and weak convection of the electromagnetic field. The shortcomings of strong convection are that strong shear and strong convection can be generated in the melt at the same time during semi-continuous casting; the present invention can fully meet the uniformity requirements of the temperature field, promote the fragmentation of dendrites, and reduce the film-like structure in the melt. The oxides are dispersed and broken into individually distributed fine particles, which can effectively refine the alloy structure. It not only increases the effective nucleation particles, but also weakens the damage of defects such as filmy oxides in the melt to the performance of the ingot, and improves the resistance of the ingot. The ability to crack cracks improves the yield of ingots.

Description

technical field [0001] The invention belongs to the technical field of semi-continuous casting of light alloys, in particular to a semi-continuous casting device and method of light alloys under the compound action of shear and magnetic field. Background technique [0002] High-strength aluminum alloy and magnesium alloy are the two most typical light alloys, and the ingot preparation link in the production process is mainly realized by semi-continuous casting. When casting high-strength light alloy ingots, especially large-scale high-strength light alloy ingots, due to their high modulus, strength and low plasticity, they are prone to hot cracking and cold cracking. Defects, once hot cracking or cold cracking occurs, the ingot material will be scrapped, reducing the yield of the ingot. [0003] Theoretically, the above-mentioned casting defects can be avoided from two aspects. One is to make the temperature field more uniform to reduce the internal stress, and the other is...

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Problems solved by technology

On the basis of conventional semi-continuous casting, the use of electromagnetic field is increased, and the electromagnetic field is used to cause strong convection in the melt to promote the uniformity of the temperature field and reduce the internal stress. To a certain extent, the alloy structure can be refined. Ingot, due to the skin effect of the electromagnetic field in the metal, the magnetic field strength acting on the center of the ingot will be relatively weak, resulting in weakened structure refinement at the center of the ingot, and the ability to regulate the uniformity of the temperature field will be significantly reduced. Moreover, the shear effect caused by the electromagnetic field is weak, and the film-like oxide cannot be dispersed and broken into fine particles distributed separately. The larger the size of the ingot, the worse the ingot's ability to resist cracks

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