水冷壁管壁厚主磁通超声波融合检测方法

壁厚是电站锅炉水冷壁管质量监测的一个关键指标，为了实现对水冷壁管的快速无损检测和质量评价，提出了主磁通检测与超声波检测相融合的壁厚检测新方法。结合主磁通检测速度快和超声波检测准确度高的特点，利用超声波测厚值对壁厚磁性检测量化模型参数进行在线标定，建立磁性信号与管壁厚度之间的关系曲线，以实现壁厚的快速定量评价。实验结果表明，主磁通超声波融合检测方法的评价精度优于统计关系模型，更适合水冷壁管质量的在线检测与实时评价。

A Method Combining the MMF Technique with Ultrasonic to Inspect the Wall Thickness for Water-wall Tube

Wall thickness is a key index for water-wall tube inspection in power plant,in order to inspect the tube quickly and evaluate the wall thickness quantitatively,a new method combining the magnetic main flux(MMF) with ultrasonic technique was proposed.The magnetic technique was used to do full inspection and locate the flaws,and the ultrasonic was employed to implement further quantitative inspection accurately.Then,the data measured by ultrasonic transducer was used to calibrate the MMF model parameters firstly,and a function was specified to fit the relations between the wall thickness and the peak value of MMF signal,thus the wall thickness can be evaluated quickly.The experimental results demonstrate that the model used in this system has better accuracy than that by the statistics relation model obviously,and it is suitable for defect evaluation in real-time.