采用凸面超声相控阵探头对管状设备进行内检测，针对水-钢二层介质的结构特征，理论分析了相控阵声场的聚焦性能。根据近场球面波束形成模型，按声束路径求得的延时时间作为各阵元的提前激发时间，设计了水-钢二层介质相控阵聚焦法则。利用CIVA软件对相控阵声场进行建模仿真研究，确定了阵元数目、阵元尺寸、超声波频率等相控阵探头参数。最后，根据优化后的相控阵参数研制了512大阵元数双层结构的圆环形探头，再通过带有人工缺陷的管状模拟试样进行检测试验。结果表明：提出的方法对腐蚀、气孔缺陷具有更好的检测灵敏度和效率，能够实现管状设备的腐蚀和埋藏缺陷的内检测。

The convex phased array probe was adopted in this paper for performing internal inspection of the tubular equipment. According to the structure characteristics of two layer medium, the paper theoretically analyzed the focusing performance of phased array acoustic field. Based on the model of near field spherical beam forming, the delay time can be obtained by the route of acoustic beam which can be used as stimulation time for each array elements. Phased array focusing law of the water-steel two layer medium is designed in this paper. The simulation on the phased array acoustic field with CIVA software is completed to determine the phased array probe parameters, including array elements, array element size, ultrasonic frequency and so on. At last,the double layer circular ring probe of 512 array elements is manufactured according to the phased array parameters which have been optimized,the test on tubular samples which contain artificial flaws is performed. Experiments indicate that this technique can detect the corrosion and the porosity flaw,with high sensitivity and efficiency. The corrosion and embedded flaws of the tubular equipment can be detected by internal inspection.