电站中高温高压部件(汽缸、主蒸汽门、调速汽门等)的紧固螺栓,在运行检修过程中经常发生断裂的现象。如何利用超声波及时地检查出螺栓中的初期裂纹,对于电站的安全运行具有重大意义。探伤原理同一螺栓的丝扣型式都是一致的,它们对超声波的反射条件也基本相同,所以在萤光屏上丝扣波的特征都是相似的。但是,一旦在某道丝扣处出现了裂纹,在萤光屏上就会出现特殊波形和一些波形的特殊变 Power station high temperature and pressure components (cylinder, main steam valve, steam valve, etc.) of the fastening bolts, maintenance and repair operations in the frequent occurrence of fracture phenomenon. How to detect the initial crack in the bolt in time by ultrasonic is of great significance to the safe operation of the power station. Flaw detection principle Same screw threaded type are the same, their reflection conditions of ultrasound are basically the same, so the characteristics of the screen on the screen are similar. However, once there is a crack in a certain thread at the screen there will be a special waveform and some special waveform changes