在役球罐焊缝的TOFD检测应用
TOFD Inspection of Welds in Spherical Tank in-Service
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摘要: 设计了超声波衍射时差法(TOFD)与手动超声(UT)及磁粉检测(MT)相结合的技术检测方案,对在役氧气球罐的对接焊缝进行无损检测。针对TOFD上下表面的检测盲区,采用磁粉检测进行了补偿检测;用UT复验了TOFD检测出的缺陷,并与X射线检测结果进行了对比分析。结果显示:针对同一焊缝,TOFD检测到多处密集型气孔缺陷,其中一处较为严重,且不达合格要求,常规超声和X射线检测只检测出较严重处的密集型气孔缺陷,也不达检测要求。相比其他无损检测方法,TOFD检测更加高效,同时验证了所设计技术方案的可行性。Abstract: A detection scheme based on flight diffraction (TOFD) and manual ultrasonic testing (UT), as well as magnetic particle testing (MT) was designed to detect butt welds in oxygen tank in-service.MT was used for the compensation detection to TOFD testing blind spots which are in the top and bottom surface of weld.Using UT re-inspects the defects which were detected by TOFD, Additionally, the results were compared with X-Ray testingresults.The results is that TOFD detects many intensive stomatal defects, one of them is serious and does not meet the qualificationrequirements.However, UT and MT only detect one stomatal defect, which also does not meet the qualificationrequirements.It showed that TOFD is more efficiency compared to other NDT methods, at the same time, it also confirmed that the detection scheme was feasible.