基于TOFD的管道焊缝无损检测技术研究

在高温、高压、高流速、高腐蚀环境下,油气长输管道焊缝处在应力和腐蚀的交互作用下极易出现各种裂纹和腐蚀缺陷。针对该问题,采用超声波衍射时差法(TOFD)开展了管道焊缝的相关检测,研究了TOFD相关信号的特征及缺陷信号的提取;对典型焊缝缺陷分析后,应用小波变换进行了增益数的模型优化。在现场,通过检测某段管道的环焊缝以及支架角焊缝,得到以下验证:TOFD可以用于壁厚大于12 mm的管道检测,可快速、准确地定位和检测焊缝缺陷,为管道完整性的评估提供理论依据。

Research on Nondestructive Testing Technology on Welding Seams for TOFD-Based Pipeline

Under the conditions of high temperature,high pressure,high velocity and high corrosion environment,various cracks and corrosion defects are easy to appear at the welding seam for the oil-gas long distance transportation pipeline due to the interaction between stress and corrosion.In order to solve the problem,time of flight diffraction(TOFD)is adopted to conduct related detection for pipeline welding seam.The TOFD related signal characteristics and the extraction of defect signal are studied.After analyzing the welding seam defect,wavelet transform is applied to gain the number of model optimization.Under the actual working condition,following verification is achieved through detecting the pipeline girth welding seam and fillet welding seam:TOFD can be used for pipeline detection with wall thickness greater than 12 mm.The welding seam defect can be rapidly and accurately positioned and detected.Theoretical basis for the assessment of pipeline integrity is provided.