为了对东风4D型机车车轴进行全面的超声波检测，设计了模拟试件和缺陷，研究了超声波探伤方法以及相应的探头。该试件为1∶1设计，针对机车车轴的各个应力集中点，在试轴上设计了12处模拟缺陷，作为探伤的对比缺陷当量。采用多种角度超声波探头对车轴进行全面检测，介绍了不同部位所选用斜探头的K值和小角度纵波探头的角度，并采用表面波探头检测车轴轴身，设计了双晶探头检测外侧压装线部位。通过多种类型和角度的超声波检测方法的共同作用，能够实现东风4D型机车车轴的全面检测。

In order to detect Dongfeng 4D locomotive axle comprehensively, the sample and defects were designed, and the ultrasonic testing methods and corresponding transducers were researched. The sample was designed 1∶1, 12 defects were designed as contrast defect for the various locomotive axle stress concentration points. Various testing methods with corresponding transducers were used to detect comprehensively, such as shear wave testing with different angle, small angle longitudinal testing with different angle, and the surface wave probe was used for the axel body, double crystal probe was designed to detect lateral press-fit line part. Through a variety of types and methods of ultrasonic testing, the comprehensive inspection could be achieved for Dongfeng 4D locomotive axle.