非焊透阶梯导波杆用于高温管道超声测厚的实验研究

高温管道；测厚；超声波；导波杆；数字超声波探伤仪；波形显示 超声测厚仪
The high temperature pipeline thickness was suggested to be measured with an ultrasonic stepped wave guide, which is partially wel ded on the monitoring point of the pipeline vertically. The cooling un it at the up-middle part of the guide was used to cool the temperature of the guide end low enough to hold the conventional ultrasonic senso r and coupling medium. Taking carbon steel as an example, circular pla te with such a waveguide was experimentally studied with digital ultra sonic flaw detector CTS-2020. It is found that the plate thickness can be deduced with the known length of the stepped section and the sound journey differences of the reflecting waves. It can be deduced direct ly without modification of temperature on the sound velocity when the temperature of the stepped section of the waveguide is ensured to be c lose enough to that of the measuring component. Compared with actual p late thickness, the absolute error of the deduced thickness is no more than 0.15 mm, which can meet the need of the high temperature pipelin e thickness monitoring.