在役球形储罐的焊接缺陷评定及验证性

在役球形储罐的定期检验中，焊缝埋藏缺陷超出相应标准时，需要按要求进行安全状况等级评定，但TSG 21—2016并未明确性质为裂纹的埋藏缺陷安全状况等级评定的相关要求。文中通过TOFD对含裂纹埋藏缺陷球形储罐进行安全评定后，选取评定图安全区域内的埋藏裂纹缺陷进行2个定期检验周期的在线监控，最终发现球形储罐使用过程中该类非活动性缺陷未发现明显扩展，解剖验证后，对裂纹未扩展原因进行了分析。文中的创新性在于将TOFD检测技术应用于球罐的埋藏缺陷的在线监测，验证了该检测方法对球罐埋藏裂纹监测方面存在一定的可行性，为同行业球罐检验提供了实践性的探索。创新点： (1)将TOFD检测技术应用于球罐埋藏缺陷的在线监测，验证了该检测方法对球罐埋藏裂纹监测方面存在一定的可行性，为同行业球罐检验提供了经验参考。(2)在满足生产工艺的前提下，对于存在一些非活动或封闭性埋藏裂纹缺陷的球罐可以不进行维修，为企业节约了成本支出，并提高了经济效益。

Evaluation and verification of welding defects of spherical tanks in service

In the regular inspection of in-service spherical storage tanks, when the buried defect of the weld exceeds the corresponding standard, it is necessary to carry out the safety condition rating as required, but TSG 21—2016 does not specify the relevant requirements for the safety condition rating of the buried defect in the nature of the crack. In this paper, after the safety assessment of the spherical storage tank with cracked buried defects is carried out by TOFD, the buried crack defects in the safe area of the assessment map are selected for online monitoring of 2 regular inspection cycles, and finally this type of inactive defects during the use of the spherical storage tank is found. No obvious expansion was found. After anatomical verification, the reasons for the failure of the crack to expand were analyzed. The innovation of this paper lies in the application of TOFD detection technology to the online monitoring of buried defects in spherical tanks, which verifies that the detection method has certain feasibility in monitoring buried cracks in spherical tanks, and provides a practical exploration for the inspection of spherical tanks in the same industry.Highlights: (1) The application of TOFD technology to the on-line monitoring of spherical tank’s embedded defects has proved the feasibility of this method in the monitoring of spherical tank’s embedded cracks, which provides an experience reference for the same industry.(2) On the premise of meeting the production process, the spherical tank with some inactive or closed buried crack defects can not be repaired, which saves the cost for the enterprise and improves the economic benefit.