小径棒材的超声检测

Ultrasonic Testing of Small Diameter Bar

小直径棒材的检测由于其曲率半径小,探头跟工件的接触不良,若采用普通直探头,用直接接触法检测时,存在杂波信号多、耦合不良、检测灵敏度较低等缺点。为解决上述问题,本文使用延迟块检测小直径棒材,因延迟块的底面为圆柱面,能与棒材完全接触,耦合效果好,声波能有效地透射入棒材,提高检测灵敏度,减少杂波,损伤判断更加容易,从而解决了单直探头直接接触法在外圆面检测的困难,为小直径棒材的检测提供了借鉴和参考。

During the ultrasonic testing of small diameter bar, the problems of interference signals, poor coupling and low detection sensitivity, are always encountered due to the small radius of the samples and the resulted poor contact between the ordinary straight probe and the samples. To overcome the mentioned issues, the delay block with a cylindrical surface is used to obtain a complete contact with the sampling bars. It is shown that the coupling effect is well and the sound wave can be effectively transmitted into the bar material, which is beneficial to increase the detection sensitivity and eliminate interference signals. As a result, the defects are easy to be found, which provides references for the testing of small diameter bars.