(a)
(b)
Figure 14. Distribution functions, n(l) in (a) base and (b) inoculated iron. The shaded areas under the n(l) curves indicate the number of active nucleation sites, Nnuc
and hence the cell count, M = 0.8 cm.
(a)
(b)
(c)
(d)
Figure 15. (a) Influence of the material mold ability to absorb heat, a and the metal temperature Ti just after pouring in the mold as well as (b) influence of the casting modulus, M and metal temperature Ti
Similar graphs are plotted for ductile iron (Fig.15c,d). Predictions are based on Eqns. (11) and (12) for gray iron with 3.14 %C, 1.98 %Si, b = 119.0o
C, Ns = 6.13 106 cm-3 and for ductile iron with C = 3.79 %C, 2.60 %Si, b = 9.8o
All of the above factors can change the graphite nucleation potential of a given melt. The inoculation process is of the highest importance in foundry practice. Hence, a detailed inoculation analysis is given using as a reference a base
46 cm-3
on the cell, N count in gray iron. C, Ns = 1.52 107
.
and an inoculated cast iron (73-75%Si, 0.75%Al, 0.75- 1.25%Ca, 0.75-1.25%Ba in the amount of 0.5%). From the published literature23 for graphite nucleation.
the following relationships are found International Journal of Metalcasting/Summer 10
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