Correlation between Mechanical Properties and Microstructures of Nodular Iron as a Tool for Quality Control Inspection

Nodular cast iron is characterized by the presence of nodule graphite in its microstructure, which lead to have good mechanical properties. Mechanical properties such as tensile strength, ductility and hardness are sensitive to the microstructure, that means the mechanical property has certain correlation with its microstructure.

In this paper, mathematical relations between a quality index of the microstructure and its graphite volume fraction, lineal and areal nodule counts, the volume fraction of ferrlte and pearlite wars established. The resulted equations are very practical tool for quality inspection in foundry practice to estimate tensile strength, ductility and hardness.