针对动车组制动管路多型号轻量化需求，研究了5A02铝合金管路端口采用旋压冲压74°扩口成形的表面质量及塑性变形特性。通过实验对不同外径(Φ15 mm×1 mm、Φ15 mm×1.5 mm、Φ18 mm×1 mm、Φ18 mm×1.5 mm和Φ28 mm×1 mm)管坯在不同旋压棒转速和进给速度下进行旋压扩口成形，对成形表面进行宏观观察、SEM微观表征、激光共聚焦显微镜粗糙度测试，以及EBSD显微组织分析。结果表明：扩口后管端表面因应力分布不均而产生明显磨损特征。Φ15mm×1mm和Φ15 mm×1.5 mm管坯的表面主要呈犁沟+磨粒混合磨损形貌，而Φ18 mm×1 mm、Φ18 mm×1.5 mm和Φ28 mm×1 mm管坯则以磨粒磨损为主。各种型号管坯的表面粗糙度均在3～6μm,且随着管径增大，粗糙度整体降低并更加均匀。EBSD分析显示母材呈典型的冷变形退火组织，以大角度晶界和丝织构为主；扩口后组织以变形晶粒为主，小角度晶界显著增多，原有纤维织构被塑性变形削弱。

To meet the multi-specification and lightweight requirements for brake pipelines in high-speed train units, the surface quality and plastic deformation characteristics of 5A02 aluminum alloy tube port flared to 74° using a spinning-stamping process were investigated. Rotational stamping and flaring forming was conducted on tube blanks with various outer diameters(Φ15 mm×1 mm, Φ15 mm×1.5 mm, Φ18 mm×1 mm, Φ18 mm×1.5 mm, Φ28 mm×1 mm) with different rotational speeds and feed speeds. The formed surfaces were examined via macroscopic observation, scanning electron microscopy(SEM) microscopic characterization, laser confocal microscopy for surface roughness, and electron backscatter diffraction(EBSD) for microstructural analysis. The results show that after flaring, the tube end surfaces exhibit obvious wear features due to uneven stress distribution. The Φ15 mm×1 mm and Φ15 mm×1.5 mm tube blanks display a mixed wear morphology of ploughing grooves and abrasive wear, whereas the Φ18 mm×1 mm, Φ18 mm×1.5 mm and Φ28 mm×1 mm tube blanks are dominated by abrasive wear. The surface roughness of all specifications of tubes falls in the range of 3-6 μm. Moreover, larger tube diameters result in lower and more uniform roughness. EBSD analysis indicates that the base material has a typical cold-deformed annealed microstructure with predominantly high-angle grain boundaries and a fibrous texture. After flaring, the microstructure is dominated by deformed grains, low-angle grain boundaries increase significantly, and the original fiber texture is markedly weakened by the plastic deformation.