Melt treatment device and method in continuous casting process of hypereutectic aluminum-silicon alloy

Abstract

The invention provides a melt processing device in a hypereutectic aluminum silicon alloy continuous casting process. The device comprises an air guide pipe, a powder spraying device, a flow guide pipe, an electromagnetic stirrer, a crystallizer, a cast ingot, an alterant, a gap channel, powder spraying holes, an alloy melt and a hot top. The top of the powder spraying device is communicated with the air guide pipe, the powder spraying device is a hollow tubular device, the plurality of powder spraying holes are formed in the lateral wall of the bottom of the powder spraying device, the gap channel is formed between the powder spraying holes and the inner wall of the flow guide pipe, the bottom of the flow guide pipe is installed on the crystallizer, the electromagnetic stirrer is sleeved on the outer lateral wall of the flow guide pipe, the alloy melt is contained in an inner cavity of the hot top, and the top of the gap channel is communicated with the alloy melt. The device has the advantages of refining primary silicon tissues, reducing alterant dosage and reducing cost.

Description

technical field [0001] The invention belongs to the technical field of metal material processing, in particular to a melt processing device in the continuous casting process of a hypereutectic aluminum-silicon alloy and a processing method using the device. Background technique [0002] Due to the advantages of light weight, high strength, high wear resistance, high heat resistance and low thermal expansion, hypereutectic aluminum-silicon alloy billets are usually used to manufacture key components such as automobile engine pistons, rotors, and swash plates. However, coarse primary silicon and segregation of primary silicon usually exist in the microstructure of hypereutectic Al-Si alloy, which seriously reduces the mechanical properties of the alloy. Under ordinary casting, the primary silicon is generally relatively thick, in the shape of five-petal star, plate, octahedron and other complex shapes with sharp edges and corners, which severely split the matrix, which reduces...

AI Technical Summary

Problems solved by technology

However, this modification process has the following defects in the continuous casting of hypereutectic aluminum-silicon alloy blanks: (1) The modification agent is usually added in the form of block or filament when used, resulting in uneven distribution of the modification agent in the melt, The effect of dispersion distribution is often not achieved, the amount of modificator added is large, the utilization rate is low, and the modificatory effect is poor

(2) The metamorphic process is often carried out in a smelting furnace or a static furnace. After the metamorphism is completed until the pouring is completed, the metamorphic effect is easy to decline

Moreover, the alloy melt has a long journey, and the metamorphic nucleation particles often collide during the flow process, and the number of nucleation particles decreases, which seriously affects the metamorphic effect of the modificator.

(3) Despite the modification treatment, the size and morphology of the primary silicon of the obtained hypereutectic aluminum-silicon alloy continuous casting billet have not been fundamentally improved. The size of the primary silicon is still large, and the average grain size is still above 70 microns. The appearance is poor, mainly lath

However, this process has the problems of primary silicon segregation and uneven microstructure distribution, and it has not fundamentally improved the dispersion and distribution of the modifier in the aluminum alloy melt. The size of the primary silicon is uneven and the shape is poor.

It also mentions the use of electromagnetic stirring for semi-continuous casting, but it does not mention how to avoid the skin effect generated during the electromagnetic stirring process, nor does it mention the on-line modifier and the on-line treatment of the melt in the continuous casting process

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