双晶直探头对船用铸钢件的超声波检测

摘要

The UT method and procedure of marine cast steel by the normal twin transducer probe were detailed in order not to have the exposed defect on the surface of work after finishing, and consequently to meet the request of the work. The concept for defect of honeycomb profile has been introduced in the article, 3 kinds of reflective waveform for defect of honeycomb profile（ airhole type, shrinkage cavity type and slag type） were analyzed mainly. The following conclusions have been testified： this method is useful to internal defect＇s evaluating of marine cast steel; this method with watching echodynamic patterns of defect is useful to locate and quantify and be qualitative quickly for defect; the method with 2-4 MHz, 14-20 mm focus of Normal twin transducer probe in Ф 3 sensitivity can be sure to the defect not appearing on the surface of work after finishing.%介绍用纵波双晶直探头对船用铸钢件机加工面进行超声检测的方法，以保证工件精加工后无外露缺陷，从而满足工件的技术要求。文章引进蜂窝状缺陷的概念，侧重于三种蜂窝状缺陷（气孔型、缩孔型和夹渣型）的超声波反射波型特征的分析。实践证明，所述分析方法有利于对铸钢件内部缺陷评定；结合对缺陷反射波的动态波形观察有助于较快速进行缺陷定位、定量和定性；采用2～4MHz、焦距15-20mm双晶直探头，Ф3mm孔灵敏度，对船用铸钢件粗加工面进行超声检测是确保精加工后缺陷不外露的较好的检测技术。