Quantitative inspection on graphite length of grey iron

Graphite length is an important item in metallographic inspection of grey iron. Computer aided quantitative metallography is developed rapidly and has become a major analytical tool nowadays. Based-moment threshold selection was adopted to binarize the metallographic image in this study. A new approach has been developed to measure the length of the graphite in cast iron with high precision. The results are in good agreement with China National Metallographic Inspection Standard Charts for Grey Iron (GB7216-87) and ASTM (A247-67). An objective and precise measurement of graphite length in grey iron is critical for developing models correlating microstructure and properties of cast iron.