超声端点衍射法测量在役管道母材疲劳裂纹高度

In-Service Pipeline Base-Metal Fatigue Crack Height Measurement by Using Ultrasonic Tip Diffraction Method

为保证核电站反应堆冷却剂系统管道在役时运行状态的良好,需要有效和准确地检测出该类管道内外壁母材疲劳裂纹高度。文章着力介绍了母材疲劳裂纹高度的检测原理、检测方法、试块设计、超声波探头参数的选择。经过大量的试验和现场检测,证明了根据管道规格,制作相应的对比试块和性能验证试块,采用5 MHz 45°横波斜探头,对于自身高度大于2 mm的裂纹缺陷,利用端点衍射法进行测量可得到准确的裂纹自身高度。

In order to ensure the coolant system pipes in the nuclear reactor run well in in-service condition, detecting fatigue crack height of base metal in inner and outer walls effectively and accurately was necessary. This paper mainly introduced the detection principle, test methods, test block designing and UT transducer parameter selection of fatigue crack height of base metal. By a great deal of testing and field inspection, it proved that through fabricating corresponding reference block and performance verification test block according to the pipes sizes, and using 5 MHz 45° shear wave angle probe, the crack height which was larger than 2 mm could be measured by using ultrasonic tip diffraction method.