由于ASG管嘴焊缝结构的复杂性，为优化其无损检测方法，改进超声波检测工艺，按照RCC-M规范要求，设计了全尺寸0°和90°ASG管嘴焊缝对比试块。通过理论分析和采用多角度探头的试验验证，确定35°和45°探头的组合可以覆盖整个焊缝的厚度范围，能有效检测出试块上的人工缺陷，且满足RCC-M标准要求。在超声波检测试验基础上，制定出了具有针对性的检测工艺。

As ASG nozzle welding structure is complex, in order to optimize its nondestructive testing, the ultrasonic testing(UT) procedures. The paper desiged whole-size ASG contrastive block(0°and 90°profile) according to RCC-M. The paper also used theoretical analysis and diverse angle probes verification, and got the conclusion that probes with refraction angle of 35°and 45°could cover the whole range of the welding thickness, and find artificial defects on the contrastive block. The result meets RCC-M requirements. In the end, the paper establishes pertinent nondestructive testing procedures according to test result.