The solidification of spheroidal graphite cast iron (SGI) plays an important role in production of sound quality castings. However, owing to the complex solidification behaviour of SGI, prepouring melt quality evaluation technique such as thermal analysis is used to predict quality of liquid metal by analysing the cooling curve pattern. In this study, an attempt has been made to investigate the role of speed of recalescence (SOR) in nucleation of graphite during solidification of SGI. Cooling curve analysis of liquid samples was carried out at different inoculation degrees. Recalescence and SOR data were obtained from thermal analysis, whereas nodule counts were obtained from microstructural examination of respective sample. It was observed that recalescence and nodule counts (nucleation sites) have a statistically significant inverse linear relationship; with the increase in recalescence, the nodule count was found to get reduced. However, the multiple values of nodule count at same recalescence degree were to be understood, which was clearly justified by SOR studies. After analysing the SOR vs nodule count relation, almost each SOR value corresponds to different nodule counts and the relation was statistically more significant. This infers that for an in-depth nodule count estimation, SOR analysis will be more helpful as compared to ∆Tr; hence, it is envisaged that speed of recalescence is true indicator of graphite nucleation as compared to recalescence in SGI.

球墨铸铁（SGI）的凝固在生产优质铸件中起着重要作用。然而，由于SGI的复杂凝固行为，预浇铸熔体质量评估技术（如热分析）可通过分析冷却曲线图来预测液态金属的质量。在这项研究中，已经进行了尝试以研究SGI固化过程中重新升温速度（SOR）在石墨成核中的作用。在不同接种度下进行液体样品的冷却曲线分析。从热分析获得重结晶和SOR数据，而从各个样品的微结构检查获得结节数。观察到，重发和结节数（成核位点）具有统计学上显着的反线性关系；随着刷新的增加，结节数被发现减少。但是，应该理解在相同的重度下的结核计数的多个值，这通过SOR研究显然是合理的。在分析SOR与结节数之间的关系后，几乎每个SOR值都对应于不同的结节数，并且该关系在统计上更为显着。这表明，对于深入的结核计数估算，与ΔTr相比，SOR分析将更有用。因此，可以设想，与SGI中的重新发光相比，重新发光的速度是石墨成核的真正指标。应当理解，在相同的复新度下，结核计数的多个值，这通过SOR研究显然是合理的。在分析SOR与结节数之间的关系后，几乎每个SOR值都对应于不同的结节数，并且该关系在统计上更为显着。这表明，对于深入的结核计数估算，与ΔTr相比，SOR分析将更有用。因此，可以设想，与SGI中的重新发光相比，重新发光的速度是石墨成核的真正指标。应当理解，在相同的复新度下，结核计数的多个值，这通过SOR研究显然是合理的。在分析了SOR与结节数的关系之后，几乎每个SOR值都对应于不同的结节数，并且该关系在统计上更为显着。这表明，对于深入的结核计数估算，与ΔTr相比，SOR分析将更有用。因此，可以设想，与SGI中的重新发光相比，重新发光的速度是石墨成核的真正指标。这表明，对于深入的结核计数估算，与ΔTr相比，SOR分析将更有用。因此，可以设想，与SGI中的重新发光相比，重新发光的速度是石墨成核的真正指标。这表明，对于深入的结核计数估算，与ΔTr相比，SOR分析将更有用。因此，可以设想，与SGI中的重新发光相比，重新发光的速度是石墨成核的真正指标。