Method for casting high-strength aluminum alloy round ingot by continuous oil gas lubrication

Abstract

The invention relates to a method for casting a high-strength aluminum alloy round ingot by continuous oil gas lubrication, which comprises the following steps: firstly, melting an industrial pure aluminum ingot in an induction furnace; after the industrial pure aluminum ingot is molten, controlling the melt temperature at 700-730 DEG C, and adding an industrial pure zinc ingot and an industrial pure magnesium ingot; stirring the melt, heating up to 710-750 DEG C, and adding Al-50Cu, Al-10Zr, Al-10Mn and Al-5Cr intermediate alloy ingots; stirring and transferring the melt to a heat-insulation holding furnace for refining and removing slag; before casting, adding Al-5Ti-B poles into the furnace for thinning the melt; in the semi-continuous casting process, adopting a continuous oil gas lubrication crystallizer; in the casting process, controlling the crystallizer compressed air pressure at 0.1-0.4MPa and the lubrication oil pressure at 0.2-0.8MPa, mixing the compressed air and the lubrication oil, and forming an oil-gas cushion film on the inner wall of the crystallizer; in the initial stage of casting, controlling the casting speed at 10-30mm / min and the cooling water pressure at 0.08-0.1MPa; and after casting for a certain length, gradually increasing the casting speed and the cooling water pressure, and keeping the casting speed and the cooling water pressure constant. The method not only can be used for successfully casting a high-strength aluminum alloy cast ingot, but also can obviously improve surface quality of the cast ingot.

Description

technical field [0001] The invention relates to a continuous oil-gas lubricated casting method for high-strength aluminum alloy round ingots, belonging to the technical field of semi-continuous casting of aluminum alloys. Background technique [0002] High-strength aluminum alloy is an Al-Zn-Mg-Cu-Zr alloy with excellent comprehensive performance, high structural strength, fracture toughness and stress corrosion resistance. It is a light-weight structural material widely used in aviation and aerospace fields. However, the content of alloying elements in high-strength aluminum alloys is often relatively high. For the representative alloy 7050, the content of Zn, Mg, Cu and other elements is as high as 12%. During the solidification process, the number of low-melting eutectic phases at the grain boundaries increases, thereby reducing the ability of the ingot to resist cracks. According to reports, the hot cracking of high-strength aluminum alloy ingots during the casting proc...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems of easy cracking and poor surface quality of high-strength aluminum alloy ingots, the present invention provides a continuous oil-gas lubrication casting method for high-strength aluminum alloy round ingots. The application of this method can not only successfully cast high-strength aluminum alloy ingots, but also significantly improve the casting process. Ingot surface quality

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