A casting method for large corrosion-resistant aluminum-magnesium alloy components

Abstract

The invention discloses a casting method of a large-scale corrosion-resistant aluminum-magnesium alloy component. A casting device comprises a platform, the top surface of the platform is a working surface, heat preservation furnaces are arranged at the bottom of the platform, the number of the heat preservation furnace is two or more, heat preservation furnace each are connected with corresponding liquid filling openings of the working surface through mutually independent liquid lifting devices, and the heat preservation furnaces can realize asynchronous liquid lifting and pressing through aliquid lifting control system, and the casting method is characterized by comprising the following steps of (1) preparation before casting; (2) multi-zone synchronous liquid lifting; (3) second-stagepressurization solidification; and (4) pressure relief. According to the casting method, the casting effect of the large-scale corrosion-resistant aluminum-magnesium alloy component can be improved.

Description

Technical field: [0001] The invention relates to a casting method of an aluminum alloy casting, in particular to a casting method of a large aluminum-magnesium alloy component. Background technique: [0002] In the field of aircraft carrier, large destroyer, island reef / shipborne artillery, civil ship and other equipment, in the face of high humidity and high salt marine climate environment, the demand and application of high corrosion-resistant aluminum-magnesium alloy castings are becoming more and more extensive. ZL305 aluminum alloy, because the Mg content is as high as 7.5-9.0%, it is easy to produce oxidation inclusions during the filling and solidification process, and its solid-liquid interval is as high as 130°C, and the mushy solidification seriously affects the feeding of castings. The current conventional low pressure and differential pressure casting technology, castings can only rely on the pouring system and pressure feeding, the solidification structure is di...

AI Technical Summary

Problems solved by technology

The current conventional low-pressure and differential pressure casting technology, the castings can only rely on the pouring system and pressure feeding, the solidification structure is difficult to control, and isolated molten pools are prone to appear in the parts with large wall thickness differences, resulting in shrinkage cavity and loose defects, resulting in the solidification structure of the casting Coarse, low performance, according to the "GB / T9438-2013 Aluminum Alloy Casting Standard" acceptance, can only reach Ⅲ ~ Ⅳ quality level, even after repeated repair welding, the pass rate is still less than 30%

[0004] Although the above-mentioned patent adopts pouring in a vacuum state, which has a certain effect on inhibiting the oxidation of castings, there are still many defects for its overall casting device and method, especially for large-scale corrosion-resistant aluminum-magnesium alloy components. The long process of melt filling will easily lead to large fluctuations in the liquid level, destroying the order and stability of the filling, and turbulent flow and insufficient pouring are prone to occur in thin-walled and suddenly cross-sectional parts of the casting.

In addition, the feeding ability of the mushy solidified casting is insufficient, and shrinkage cavities and porosity defects appear in the thick hot joint and the wall thickness difference

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