bending fatigue短语¹³¹⁶²⁰⁺³ 基本例句 弯曲疲劳 Results showed that ferrite net and lower hardness due to low cooling rate, coarser finish machining resulted in the fracture during earlier stage of rotary bending fatigue test. 结果表明，冷却不足使组织中出现网状及小块状铁素体，导致硬度偏低，加之磨削加工痕迹较粗是引起前轮毂早期断裂的原因。 cnki