钢杆小裂纹最佳涡流检测参数的实验研究

为了提高棒料钢杆小裂纹涡流检测的精度,减小由于检测参数的不恰当选取带来的非线性误差,基于实验模型,采用涡流检测仪和外置式探头,对25#钢3种不同直径0.1 mm深的裂纹在不同工作频率和不同提离值下进行涡流检测,得到检测的相位信息.通过研究不同工作频率和不同提离值对相位信号的影响,根据线性拟合平均标准差为最小原则,得到了棒料小裂纹涡流检测参数与相位信号呈线性关系的最佳检测参数区段,这对提高棒料小裂纹检测精度和外置式钢棒涡流检测参数的选择具有重要的指导作用.

Experimental Study on the Best Testing Parameters in Eddy Current Testing Method for Small Crack of Steel Bar

In order to improve the accuracy of eddy current testing of steel bar with small cracks and reduce the nonlinear error due to select inappropriate testing parameters,25# steel bars with 0.1 mm crack depth were detected by using the eddy current detector and the external probe under different frequency and lift-off value based on experimental model,and then the phase information was obtained.The influences of working frequency and lift-off value on the phase signals were studied for the eddy current testing.According to the minimum principle for the average standard deviation of linear fit,the best linear section was achieved between the detection parameters of the eddy current testing signal and phase parameter,which raises the detection accuracy of the bar with small cracks,and has important guiding role for choosing the eddy current testing parameters of external bars.