某些要求高的小直径薄壁管材,其内部缺陷深度不允许超过几十微米,因此必须进行无损检查。超声探伤是发现此种微小缺陷的有效方法,目前已普遍采用。在生产中,超声波探伤既要能发现超标准的缺陷,又要满足生产率的要求。实践中发现线聚焦超声波探伤达不到规定的精度要求,点聚焦能满 Some demanding small diameter thin-walled pipe, the depth of the internal defects do not allow more than tens of microns, it must be non-destructive examination. Ultrasonic testing is to find such an effective method of small defects, has been widely used. In the production, ultrasonic flaw detection should not only find out the standard defects, but also to meet the requirements of productivity. In practice, it is found that the line-focused ultrasonic flaw detection can not meet the required accuracy requirements and the point-focusing can be full