The objective of the research was to determine the influence of boron on the crystallization process and microstructure of ductile cast iron.

In the case of ductile cast iron it is a vital issue because even as little as trace presence of boron changes the properties of ductile cast iron

in a significant way. With the use of a new ATD-4 (TDA) tester and CRYSTALDIGRPAH converter it was possible to measure the

crystallization process parameters of the same alloy with four different contents of boron in one mould. Four samples with different boron

contents were extracted, their microhardness was measured and quantitative analysis of microstructure was conducted. Obtained results

allowed to state that with increasing content of boron the amount of graphite precipitates decreases, the amount of pearlite precipitates

increases, the shape of graphite precipitates deteriorates and hardness increases. It is also planned to perform additional testings with boron

contents between previously tested values.