本文介绍声速法检测球铁件的试验方法和应用实例,并就存在缺陷情况下,声速值与延伸率不时应;用双探头穿透法在一道工序同时解决检测和探伤等几个问题进行了初步探讨。最后提出在应用声速法解决铸件的缺陷检测时应辅以的其它方法。 This article describes the test method and application examples of the sound velocity method for detecting ductile iron pieces, and in the case of defects, the value of sound velocity and elongation rate from time to time; with double probe penetration method in a process to solve several problems such as detection and flaw detection Preliminary discussion. At last, some other methods which should be supplemented when applying the sonic velocity method to solve the defect detection of castings are put forward.