不锈钢小径管跑道型脉冲涡流测厚传感器研究

Research on racetrack-type sensor for thickness measurement of stainless-steel pipe with small diameter using PECT

脉冲涡流检测(PECT)已在铁磁管道检测中得到广泛应用。然而,由于不锈钢小径管的非铁磁性导致其自身无法聚焦磁场,脉冲涡流检测存在困难。提出研究跑道型测厚传感器,减少检测中的电磁能量耗散,扩大传感器有效覆盖区域。首先,分析比较了跑道型和圆柱型激励线圈在小径管上的有效覆盖区域,指出跑道型传感器的优势。然后,基于已有三维管道解析模型计算跑道型线圈的线圈系数,建立跑道型传感器的解析模型。据此研究跑道型传感器在不锈钢管道上的测厚性能并进行实验验证。实验结果表明:跑道型脉冲涡流传感器更适合不锈钢小径管测厚。

Pulsed eddy current testing(PECT)has been widely used for ferromagnetic pipelines detection.However,in case of non-ferromagnetic pipelines with small diameters,which results in itself can not focus electromagnetic fields like ferromagnetic materials,there are still problems to be solved.A type of sensor with a racetrack-shaped driver coil is proposed,which can effectively reduce the electromagnetic energy dissipation and expand effective coverage area of sensor.Firstly,effective coverage area of racetrack-shaped and cylindrical exciting coils in small-diameter pipe is analyzed and compared.Then,based on analytical model for 3D pipe to calculate coil coefficient of racetrack-shaped coil,build analytical model for racetrack-shaped sensor.Based on the analytical model,the performance of the racetrack-type sensor on the thickness measurement for a stainless-steel pipe are studied and experimentally verified.The results show that the racetrack-type pulsed eddy current sensor is more suitable for thickness measurement for stainless-steel pipes with small diameters.