超声波检测中61°和45°缺陷反射波形的识别

The Identification on Reflection Waveform of 61° and 45° Defect by Ultrasonic Testing

在对某锻造环件进行超声波检测时,在一个端面发现有较大面积的超标反射回波,但是在另一端面却没有对应的波形显示,并且未发现缺陷波时的底波却下降了,由于该环形件的高度和衰减系数均较小,所以初步判定存在与声束入射面夹角较大的缺陷或密集小缺陷。荧光与金相验证试验证明,零件的端面和内圆周面存在锻造折叠裂纹,该裂纹与入射纵波声束轴线成61°和45°夹角。定性分析了超声波检测时深度位置为33和20格处的两个特殊波形,通过定量计算,证实了其为61°和45°缺陷的特殊反射波形。试验分析为在实际检测中区别61°纵波产生的变形横波以及45°反射纵波提供了思路,避免了缺陷的误判。

During the ultrasonic testing for a forging ring, a large area rejected reflection waveforms were found on an end, but at the other end, the corresponded waveforms were not displayed, while the bottom reflection waveforms were in low amplitude. Because of the ring part was low in height and attenuation coefficient, so it was judged that there was a defect with large angle between defect extending direction and the sound beam, or there were low density defects. Fluorescence with the metallographic verification testing proved that there was a noodle folded forging cracks at the end parts and inner circumference, the crack and the incident longitudinal wave beam axis being at 61° and 45° angle. The ultrasonic testing depth of two special waveforms which located at displaying screen 20 and 33 were qualitatively analyzed, which were confirmed to be the reflection waveform of defect with 61° and 45° angle. It was helpful to identify the 61° and 45° defect and avoid the defect misjudge.