交流电荧光磁粉检测深度实验研究

Experimental study on detection depth of alternating current fluorescent magnetic powder

磁粉检测是铁磁性承压设备焊缝及其原材料、机加工部件表面及其近表面缺陷检测的重要方法。为探究正弦波、方波、三角波3种交流电在不同频率下磁粉检测深度差异,对3种周期性交流电展开谐波分析,设计并制造了不同埋深的人工刻槽及变频交流磁轭实验检测系统,在相同的荧光磁粉检测工艺条件下来探究3种变频交流电磁粉检测深度差异。结果表明:方波比正弦波、三角波在检测近表面有一定埋深的非开口缺陷上具有更深的检测深度及更高的检测灵敏度,因此方波交流电可作为磁粉检测励磁电流种类的一种有益补充。

Magnetic powder detection is an important method to detect the welding seam and its raw materials of ferromagnetic pressure equipment as well as the surface and near surface defects of machined parts. To investigate the difference of magnetic powder detection depth when three types of alternating currents(including sine wave, square wave, and triangular wave) were used at different frequencies, the experimental detection system of artificial slot and variable frequency alternating current magnetic yoke with different buried depths was designed and manufactured. The difference of detection depth of three kinds of variable frequency alternating current electromagnetic powder was explored under the same fluorescent magnetic powder detection conditions. The results showed that compared to the sine wave and triangular wave, the square wave had a deeper detection depth and higher detection sensitivity during the detection of non-open defects near surface with certain burial depth. Therefore, the square wave alternating current could be used as a useful complement to exciting current for magnetic powder detection.