利用相控阵超声检测技术来检测钢轨核伤，首先建立钢轨核伤检测模型并分析，发现探头折射角、轨面偏斜角以及距轨面中心线的偏移量是影响核伤检测的主要因素。然后将理论计算与仿真分析相结合，得到适用于钢轨核伤检测的相控阵探头最佳参数。最后基于该参数进行相控阵探头设计，分别在60轨和75轨上加工多种类型的损伤并利用相控阵探头进行检测。结果表明，该相控阵超声探头对所有损伤的检出信噪比均大于12 dB，即基于相控阵探头的钢轨核伤检测技术可以适应不同轨型高度、轨鄂倾角的变化，实现轨头区域的超声全覆盖。

Phased array ultrasonic technology was used to detect rail transverse defects. First, the rail transverse defect detection model was established and analyzed. It is found that refraction angle, the inclination angle and transverse position of the probe on rail surface are the main factors that affecting the defect detection. Then, by combining the theoretical calculation and simulation analysis, the optimal parameters of phased array probe for rail transverse defect detection were obtained. Finally, based on the parameters above, the phased array probe was designed and tested on various types of damages on 60 rail and 75 rail respectively. The experimental results show that the signal-to-noise ratio of the phased array ultrasonic probe for all defect detection is greater than 12 dB, that is, the rail transverse defect detection method based on the phased array probe can adapt to the changes of the heights of different rail types and the change of rail jaw angle, and the rail head area was fully covered by ultrasonic.