钢管通孔直径对涡流检测信号的影响研究

Study on Eddy Current Testing Signal under Different Through-hole Diameters of Steel Tube

为研究通孔直径在钢管涡流检测中对检测信号的影响,开展了不同磁化强度下钢管通孔涡流检测试验,研究了不同直径通孔随磁化电流的信号变化特征。试验结果表明：通孔直径一定时,在非饱和磁化区（6~18 A）内,信号幅值随电流的增加先增大后减小,相位角随电流的增加逐步上升,在饱和磁化区（20~22 A）内,检测信号成形较小或严重扭曲,相位变化杂乱无章;当磁化电流一定时,信号幅值随通孔直径的增大而增大,不同直径通孔间信号相位角在非饱和磁化区（6~18A）内,最大值与最小值的极值偏差在10°~18°范围内变化,差异较小,而在饱和磁化区（20~22 A）信号相位角变化起伏较大,无明显规律。试验研究结果可用于指导钢管涡流检测工程实践。

The effect of through-hole diameter of steel tube on eddy current testing（ ECT） signal is not clear. An ECT experiment of the through-hole of steel tube under different magnetization current is carried out. The ECT experiment is to study on ECT signal under different through-hole diameters with different magnetization current. The experimental results show that when the through-hole diameter is constant,under the region of unsaturated magnetization（ 6 ~ 18 A）,the signal amplitude increases first and then decreases with the increase of the magnetization current,signal phase increases gradually with the increase of the magnetization current. Under the region of saturated magnetization（ 20 ~ 22 A）,the graph of ECT signal is so small or seriously distort,the variation of signal phase is disorder. When the magnetization current is constant,signal amplitude increases with the increase of through-hole diameter; under the region of unsaturated magnetization（ 6 ~ 18 A）,the extreme deviation of the maximum and the minimum of different through-hole diameters＇ signal phase varies in 10° ~ 18°. Under the region of saturated magnetization（ 20 ~ 22 A）,signal phase＇s changing is volatile,and there is not obvious regularity. The test results provide some valuable references for ECT on the steel tube in engineering practice.