P91钢焊缝蠕变非线性超声检测中的衰减修正方法研究

Research on Attenuation Correction in Nonlinear Ultrasonic Testing for Creep Status Evaluation of P91 Weldment

从理论上分析了衰减对非线性超声测量值的影响,并根据实际检测条件提出了一种利用时域能量对衰减进行修正的方法。以不同蠕变状态的P91钢及其焊缝为检测对象,对比了衰减修正前后的非线性超声测量值,实验结果证明,在蠕变程度较高或衰减较大的条件下,该方法能够有效的修正衰减对非线性系数测量值的影响,应用该方法可以对P91及其焊缝的蠕变状态做出更为准确的评价。

The distortion of nonlinear ultrasonic measurement caused by attenuation was analyzed the-oretieally. According to practical testing condition, an attenuation correcting method was suggested,which used time domain energy as a correcting parameter. To verify this attenuation correcting meth-od, P91 steels and welds with different creep status were selected as inspection objectives in a testingexperiment. Attenuation corrected and non-corrected nonlinear ultrasonic measurement results of dif-ferent creep status were compared respectively. And the results show that while creep is well devel-oped or attenuation is large, the suggested method can effectively correct the distortion of nonlinearultrasonic measuring results caused by attenuation. In other words, this method can evaluate creepstatus of P91 steels and welds more accurately.