提高抽油杆微裂纹漏磁检测精度灵敏度新方法

针对目前漏磁检测抽油杆微裂纹的精度和灵敏度不高的现状,提出一种通过拉伸抽油杆使微裂纹张开后的漏磁检测法。该方法在材料弹性范围内,使用液压装置拉伸微裂纹,在4MPa拉伸应力下对带有0.1、0.3mm人工裂纹45钢的试验样杆的检测结果表明,0.1mm微裂纹输出增加值为0.243mm;0.3mm裂纹输出增加值为0.097mm,不仅能够保证抽油杆的无损检测,而且与常规方法相比,在相同条件下,可提高微裂纹的检测精度和灵敏度。这为提高现场抽油杆漏磁检测微裂纹的精度和灵敏度提供了一个有效的途径。

A way to improving accuracy and sensitivity of sucker rod crack using magnetic flux leakage inspection

The micro-crack for sucker rod is inspected by magnetic flux leakage inspection by now, but it is not good for accuracy and sensitivity. This article puts forward a new way of magnetic flux leakage inspection through stretching sucker rod by liquid force in the flexible scope of the material. A 45# steel specimen with artificial crack of 0.1 mm and 0.3 mm is adopted to verify the method.The results show that it can not only ensure NDT, but also improve the inspecting accuracy and sensitivity. It is a valid path for improving sucker rod crack inspection in oilfield.