6-series railway vehicle suspension arm aluminum profile and preparation method thereof

The invention discloses a 6-series railway vehicle suspension arm aluminum profile which contains the following metal substances in percentage by mass: 0.6-0.7% of Si, less than 0.15% of Fe, 0.5-0.7% of Mg, 0.02-0.25% of Mn, less than 0.01% of Cu, 0.1-0.25% of Cr, less than 0.05% of Zn, 0.03-0.06% of Ti and the balance of Al. The invention also discloses a preparation method of the 6-series railway vehicle suspension arm aluminum profile. The 6-series railway vehicle suspension arm aluminum profile has optimized chemical components as compared with the aluminum profile in the prior art, the Mn element content is enhanced to 0.2%, and the Cr element content is enhanced to 0.12%; the Mn can be utilized to enhance the recrystallization temperature characteristic and inhibit the crystal grains from growing, thereby refining the crystal grains of the profile and enhancing the microstructure of the material (grain refinement); and the optimized aluminum profile has the advantages of high tensile strength, high yield strength and high elongation percentage.