半轴断裂原因分析

采用原子发射光谱仪、光学电子显微镜等对某汽车半轴的断裂失效原因进行了分析。结果表明:半轴断裂是由于在半轴的基体显微组织中存在有大量的网状铁素体、沿晶界和晶内存在针状魏氏体、奥氏体晶粒粗大且大小不均匀、超尺寸非金属夹杂物等缺陷,轴颈部的过渡圆角小,在交变应力作用下产生的疲劳断裂。改进轴的设计和热处理工艺,可防止半轴发生断裂

Fracture Failure Analysis for Automotive Axle

By atomic emission spectrometer,optical and electron microscopy analyzes the causes fracture on the left rear axle of a car.The results showed that： fracture of the left rear axle is due to the existence of a large number of defects.Mesh ferrite,acicular Widmanstatten body along the grain boundaries and memory in the austenite grain thick and uneven in size,super-size nonmetallic inclusions,in the microstructure of the matrix of the left rear axle.Small axis of the neck fillet,alternating stress fatigue fracture.Improve the design and heat treatment process to prevent the rear axle was broken.