Abstract
This paper reports an application of nondestructive testing method to estimate the microstructure of the thin wall ductile cast iron with casting surface. To make thin wall ductile cast iron without chill structure, processing techniques have been developed recently. The microstructure and mechanical properties of ductile cast iron were affected by the thickness of the castings, nondestructive testing method to evaluate the properties is required. Eddy current testing and microstructure observation were performed to the ductile cast iron specimen having the thickness of 2mm and 4mm. The experimental results suggested that difference of the pearlite ratio and existence of the chill structure of the ductile cast iron can be distinguished by the eddy current signals obtained by the measurement via casting surface.
