Process for smelting and lower-pressure casting of aluminum alloy wheel hub

Abstract

The invention discloses a process for the smelting and low-pressure casting of an aluminum alloy wheel hub, which comprises: 1, putting an aluminum alloy smelting material into a smelting furnace for smelting, and when the temperature in the smelting furnace reaches 740 to 760 DEG C, introducing nitrogen into the smelting furnace to blow a refining agent into the body of the furnace for refining;2, transferring the molten aluminum alloy to a tundish from the liquid outlet of the smelting furnace, adding an Al-Sr intermediate alloy, mischmetal (Re) and an Al-Zr intermediate alloy into the tundish to perform modification and refinement treatment under a condition of a temperature of 710 to 730 DEG C, and blowing nitrogen to the tundish to perform secondary degassing of the molten aluminum alloy; 3, transferring the molten aluminum alloy in the tundish to a casting holding furnace, adding a slag decomposing agent into the holding furnace to remove slag and blowing nitrogen into the holding furnace to perform tertiary degassing; and 4, pressing the molten aluminum alloy into a mold by a method of prepressing, pressure stabilizing, pressurizing and pressure keeping to perform casting.The process can effectively discharge slag and degas, has excellent modification and refinement effects and contributes to improvement in product quality.

Description

Technical field: [0001] The invention relates to a melting and low-pressure casting process of an aluminum alloy wheel hub. Background technique: [0002] Aluminum alloys are subject to non-metallic inclusions (AL 2 O 3 etc.) and one of the metals with the most serious hydrogen pollution, so the purification treatment of aluminum alloy melt is an important method to improve the performance of the alloy, and it is also the key to improve the purity of the aluminum alloy melt. Since the inclusions and hydrogen in the molten aluminum are accompanied by and interact with each other, the two processes of hydrogen removal and impurity removal are related and different. Various purification methods have a main role, but they also have another role. Therefore, only one process is used in the actual production process, and it is very difficult to effectively remove impurities and degas at the same time. [0003] In addition, for high-performance aluminum alloy automobile wheels, i...

AI Technical Summary

Problems solved by technology

However, the phase composition, morphology and distribution of the Al-Ti-B refiner are extremely sensitive to factors such as the structure, solidification and solid-state treatment of the aluminum alloy melt, resulting in large differences in the microstructure and refinement effect, that is, in completely the same Under the conditions of alloy composition and casting process, due to the difference in the structure of the micro-auxiliary materials used, the structure and performance of aluminum products fluctuate unpredictably, and it is difficult to control the production quality of aluminum products.