Equivalent charpy-V impact criteria for nodular cast iron

The relevance of the Charpy-V test for nodular cast iron is re-examined here and as a result, a new definition of an equivalent energy criterion for nodular cast iron is proposed. Attempts to transfer the Charpy requirements developed for steel to nodular cast iron have not been successful. Actually a recent conclusion was that “Charpy impact testing is neither an accurate nor acceptable way to measure impact toughness in cast iron. It is inappropriate to use it as a means of comparison between cast iron and steel.” The reason for this conclusion lies in the fact that nodular cast iron has different transition behaviour than steel and they experience notches differently.