The application of aluminum profiles in the field of rail transit can improve the payload of rail vehicles, save fuel and reduce vehicle maintenance costs. Compared with the traditional vehicle manufacturing materials weathering steel and stainless steel, aluminum profiles can reduce the weight of the car body by 50%, and have good adaptability to high-speed lines, multi-curved lines, rolling lines and harsh environments, so it has become the preferred material for urban subway, high-speed railway and freight railway rail vehicles. At present, aluminum profiles in Japan Tokyo subway and Shinkansen rail vehicles have been widely used, China's four kinds of railway passenger dedicated line EMU CRH1, CHR2, CRH3 and CRH5, in addition to CRH1 stainless steel material, the remaining three kinds of car body are aluminum alloy material, generally speaking, the speed of more than 250 kilometers per hour high-speed trains are aluminum alloy material.