电磁超声检测中高温对横波声速的影响

Influence of High Temperature on Shear Wave Velocity of EMAT Testing

针对高温蒸气管线常规方法无法在线检测的问题,采用电磁超声（Electromagnetic Acoustic Transducer,EMAT）技术高温测厚。讨论在25~400℃温度下,通过EMAT测厚仪测定不同温度及厚度下试板的壁厚,计算各温度下的横波声速,得到Q345R材料的横波声速随温度的变化规律,用以修正不同温度下EMAT实际测厚值。结果表明EMAT技术能够满足高温主蒸气管网的在线检测。

In order to solve the problem that steam pipe line can＇ t be measured on line with conventional method,the Electromagnetic Acoustic Transducer（ EMAT） technology was adopted to measure the thickness under high temperature.Under 25 ~ 400 ℃,the thickness of sample plate was measured under different temperature and thickness by EMAT thickness gauge,shear wave velocity was calculated,and the change rule of shear wave velocity of Q345 R material with temperature was obtained,which is used to correct the actual thickness value of EMAT at different temperature. The result shows EMAT can satisfy online detection of steam piping at high temperature.