Chvorinov’s rule and determination of coefficient of heat accumulation of moulds with non-quartz base sands

Application of the „Chvorinov’s rule“ for calculation of the total time of casting solidification made also possible to determine chilling effect of foundry moulds (coefficient of heat accumulation of the mould, bf) with use of mixtures with new kinds of non-quartz base sands (Magnesite, Chromite, Olivine, Dunite, Kerphalit). Processes by several authors (G. Halbart, A. I. Vejnik, G. A. Anisovich) were used for mathematical treatment of measurement results and determination of bf. The highest values were achieved for magnesite moulds followed by chromite ones; the lowest values, approximately half-ones, represented the Dunite moulds. At the same time the results made possible to determine „the Chvorinov’s mean solidification constants“ (k) that are in direct proportional dependence on bf and indirect proportional to solidification time (τ1).