基于全聚焦相控阵超声的叶根槽裂纹检测

汽轮机转子受复杂应力和高温的多重作用，常在反T型叶根槽部位产生疲劳裂纹，导致断裂事故。针对此问题，提出全聚焦相控阵超声的检测方法。推导了全聚焦相控阵超声的采集及成像公式，制备了专用试件，在端壁上倒圆（F1）采用线切割方法预制人工缺陷，采用全聚焦相控阵超声检测，并与常规超声进行了对比。结果表明，全聚焦相控阵超声检测精度高，适应性强，具有较好的工程应用价值。

Research on Crack Detection of Root Groove Based on Total Focusing Phased Array Ultrasonic

Steam turbine rotor is one of the key components of generator set. Fatigue cracks often occur at the anti T-root groove under the multiple effects of complex stress and high temperature, which leads to fracture accidents. The paper presents the total focusing ultrasonic phased detection method to solve the difficult problem of crack detection of anti T-root groove. In this paper, we deduced the transmitting sound field of total focusing phased array ultrasonic, and prepared the specialized specimens. Artificial defects are prefabricated by wire cutting method in the inverted circle (F1 area). Total focusing phased array ultrasonic is adopted to detect defects and compared with conventional ultrasound. The results show that total focusing phased array ultrasonic has high detection accuracy, strong adaptability and the good engineering application value.