保温管道脉冲涡流检测U型探头的试验研究

Experimental Study of Pulse Eddy Current Testing U-Shaped Probe in Insulation Pipeline

针对有包覆层铁磁性管道壁厚减薄缺陷的不拆卸在线检测,提出两种U型脉冲涡流检测探头,分别对有外部腐蚀及内部局部腐蚀的管道进行检测。研究结果表明:对于带包覆层的外部缺陷采用半圆形U型探头的检测效果更佳;而对带包覆层管道内壁局部减薄缺陷检测,建议采用直角形U型探头。当腐蚀深度大于2 mm的缺陷建议采用半圆形U型探头;当腐蚀深度小于2 mm局部缺陷建议采用直角形U型探头。

As for wall-thinning problem of coated ferromagnetic pipeline, two kinds of U-shaped probes were proposed to detect pipelines with external corrosion and internal local corrosion, respectively. Experimental results indicated that semicircular probe was more effective for the external. However, in the testing of pipelines with internal local wall-thinning, right-angled probe was preferred under the conditions of different coating materials and emission frequencies. When the corrosion depth is more than 2 mm,it is suggested to use a semi-ciroular U-probe,while when the corrosion depth is less than 2 mm,the right-angle U-probe is recommended.