一、前言超声、射线和电磁探伤法是当前无损检测技术的三大支柱。超声波探伤法是利用材料本身和内部缺陷声学性质的差异对超声波传播情况的影响,来探测材料内部缺陷的。因为超声波探伤法具有灵敏度高,穿透力强,检验速度快,成本低和对人体无害等优点,故目前已广泛应用于工农业生产各部 I. Foreword Ultrasound, radiography and electromagnetic flaw detection are the three pillars of the current NDT technology. Ultrasonic flaw detection method is to use the material itself and the internal defects of the acoustic properties of the difference between the impact of ultrasonic propagation to detect defects within the material. Because ultrasonic testing method has the advantages of high sensitivity, strong penetration, fast inspection, low cost and harmless to the human body, it has been widely used in various industrial and agricultural production ministries