以厚度为2.0 mm的S500MC微合金高强钢板为材料，采用液压成形工艺制造汽车轮辋，通过有限元方法分析该轮辋的疲劳性能，并与常规滚压成形2.3 mm均匀壁厚SPFH540中强度低合金钢轮辋和2.0 mm均匀壁厚S500MC微合金高强钢轮辋进行对比。结果表明：液压成形轮辋壁厚的最大减薄率为10.9%；液压成形轮辋的截面弯曲应力和径向应力变化趋势与2种滚压成形轮辋的一致，说明轮辋局部减薄不会使其所受应力发生明显变化；液压成形轮辋的最大弯曲应力和最大径向应力低于该钢的屈服强度，最大弯曲应变和最大径向应变均远小于屈服应变，且疲劳性能安全系数均大于1，表明壁厚局部减薄不会影响轮辋的弯曲和径向疲劳性能。

With 2.0 mm thick S500MC microalloyed high strength steel plate as raw material, an automobile rim was manufactured by hydroforming process. The fatigue properties of the rim were analyzed by finite element method, and were compared with those of conventional rolling formed SPFH540 medium strength low alloy steel rim with uniform wall thickness of 2.3 mm and S500MC microalloyed high strength steel rim with uniform wall thickness of 2.0 mm. The results show that the maximum reduction rate of wall thickness of hydroformed rim was 10.9%. The change trend of section bending stress and radial stress of the hydroformed rim was consistent with those of the two rolling formed rims, indicating that the local thinning of the rim did not significantly change the stress of the rim. The maximum bending stress and radial stress of the hydroformed rim were lower than the yield strength of the steel, the maximum bending strain and radial strain were far less than the yield strain, and the fatigue property safety factor was greater than 1, indicating that the local thinning of wall thickness would not affect the bending and radial fatigue properties of the rim.