pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (9권3호 228-236)
The Effect of Graphite Morphology on the Propagation of Ultrasonic Wave in Ductile Cast Iron
구상흑연주철에서 초음파 전파속도에 미치는 흑연형상의 영향
Kye-Wan Lee*, No-Seok Yang**, Un-Su Park**
*Hanyang University, **Graduate school of Han Yang univ.,
The relationships between nodularity, tensile property and ultrasonic velocity were studied in ductile iron castings having similar matrix structure. Also, the effects of heat treatment and the number of graphite nodules on the ultrasonic velocity were investigated. The results were as follows 1. The ultrasonic velocity increased proportionally with increassing nodularity and tensile strength. 2. The ultrasonic velocity in annealed and normalized state decreased average 1.7% and 3.4% respectively than that in as cast state. 3. The ultrasonic velocity increased with increasing the number of graphite nodules. Therefore, ductile iron castings can be evaluated in the only case of castings having the same manufacturing history by ultrasonic velocity.