Effect of carbon equivalent and spheroidizer addition on the morphology of strip cast white cast iron plate

A fine and laminate solidification structure is a feature of cast iron strips produced by using strip casting. To determine the influence of the carbon equivalent value (CE) and spheroidizer addition containing magnesium on the eutectic cementite and graphite particles, samples with different carbon contents, silicon contents and different amounts of spheroidizer addition were prepared in this study, The experimental results show that the solidification structure is dendritic in the near-surface region with an equiaxed cell shape in the centre region, The area fraction of eutectic cementite increases with an increasing CE value in hypoeutectic specimens and the cementite morphology changes with a change in carbon and silicon content, The graphite nodule count and area fraction remain low until the CE value reaches 4.0, When the CE value exceeds 4.0, the graphite nodule count and area fraction significantly increase with an increasing CE value, Mg-containing spheroidizer can dramatically improve the graphite nodularity and increase the nodule count. In addition, some inclusion particles exist at the centres of spheroidized graphite nodules, These particles mainly contain Mg, S, Ca, La, Ce and Si.