针对换热器管板角焊缝的结构特征,分析了相控阵声场的聚焦性能。以波束的主瓣尖锐、较低的旁瓣、消除栅瓣为相控阵探头的设计准则,对相控阵参数进行优化分析。利用CIVA软件对相控阵声场进行建模仿真,确定了阵元数目、阵元尺寸、偏转角、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探头,并进行了角焊缝试样的检测试验。试验结果表明,优化后的探头可以有效地检测出换热器管板角焊缝中的气孔、未熔合等缺陷。

According to the structural characteristics of heat exchanger tube-tubesheet welds,this paper theoretically analyzes the focusing performance of phased array acoustic field. The criteria of phased array probe design are the sharper main lobe beam,the lower side lobes,and no grating lobe. The optimization analysis of phased array parameters and the simulation on the acoustic field with CIVA software are completed to determine the phased array parameters,including array elements,array element size,deflection angle,ultrasonic frequency and so on. At last,the probe is manufactured according to the optimized phased array parameters,and the tests on samples are performed. Experiments indicate that this technique can effectively detect the porosity flaw,incomplete fusion flaw and so on.