Inner surface defect inspection for thick wall pipe of austenitic stainless steel based on ultrasonic TOFD

摘要：

Austenitic stainless steel is widely used in thick wall primary pipe at nuclear power plant.Coarse grain size of austenitic stainless steel is the cause resulting in acoustic wave attenuation, which makes ultrasonic testing challenging. For inner surface defect inspection based on ultrasonic time of flight diffraction (TOFD), probe angleis proportional to acoustic wave attenuation. So conventional probes, such as 45° probe, 60° probe and 70° probe, cannot be carried out to detect inner surface defect of thick wall austenitic stainless steel pipe accurately. TOFD testing using 20° probe is proposed and the characteristic of acoustic wave is analyzed. Through TOFD testing of artificial and practical defect, optimum testing process of 20° probe for inner surface defect of thick wall austenitic stainless steel pipe is demonstrated. The testing signal and image feature of 20° probe are cognized. The result indicates that: sensitivity, accuracy and signal-to-noise ratio of 20° probe are better than that of conventional wedge. Artificial inner surface defect with height of 2mm can be effectively distinguished by optimum testing process of 20° probe. The location and sizing of inner surface defect of thick wall austenitic stainless steel pipe can be measured well with this technique.

关键词： Thick wall pipe Austenitic stainless steel Inner surface defect inspection Ultrasonic TOFD 20° probe

作者: Zhen Dai Wei Li Xiaojun Hao Xiaoguang Niu Shangqian Jing Jifeng Zhao

作者单位: Guodian Science and Technology Research Institute, Nanjing 210031, China Hebei Electric Power Research Institute, Shijiazhuang 050021, China

会议类型: 国际会议

会议名称: 2012 International Symposium on Structural Integrity 2012国际结构完整性学术研讨会 ISSI 2012

会议地点: 济南

会议语种:英文

页码: 405-409

在线出版日期: 2012-10-31（万方平台首次上网日期，不代表论文的发表时间）