Manufacturing method of aluminum alloy for railway vehicle body

The invention relates to a manufacturing method of aluminum alloy for a railway vehicle body. The manufacturing method of the aluminum alloy sequentially includes the steps of prepurging, smelting, primary refining, secondary refining, standing, casting and homogenizing, and further includes the superheating treatment process and the quenching process. After primary refining, aluminum alloy melt is subjected to superheating treatment and quenching and then subjected to secondary refining. By performing superheating treatment on the aluminum alloy melt, the melt structure is switched into a disordered state from a short-range ordered state similar to a solid phase; then, by performing quenching rapidly, molten aluminum alloy is rapidly cooled to a casting temperature without loosing effects. In this way, the number of active crystal nucleuses generated by non-spontaneous crystallization of the molten aluminum alloy is reduced; although spontaneous crystal nucleuses are small, the structure of a cast ingot can be better refined, and a more compact cast ingot structure can be obtained. The performance of the aluminum profile produced by the cast ingot in the method is better than that of aluminum profiles produced by cast ingots in traditional methods.