Abstract
The research was done to improve the impact property of the black heart malleable cast iron by adding small amounts of special elements to it. First the effects of addition of C, Si, Mn, P, S, and Cr which are the fundamental elements to malleable cast iron were investigated.
The results were summarized as follows. C, Si, Mn, P and S decrease the impact property of the malleable cast iron, so low contents of these elements are desirable concerning only to the impact property. Cr increases the maximum absorbed energy of malleable cast iron with the content of 0.1%. so adding of Cr to this amount is effective to improve the toughness of the iron.
