Effect of Alloying Elements on Primary Dendrite Arm Spacing in Iron-base Alloys

Abstract

The influence of the solidification rate R, the temperature gradient G and the kind and amount of solute on primary dendrite arm spacing are investigated in unidirectionally solidified Fe-C, Fe-P, Fe-0.5%C-P and Fe-0.5%C-S alloys.
The effects of the kind and amount of solute on primary dendrite arm spacing are discussed on the basis of Okamoto-Kishitake's equation.
The results are summarized as follows.
1) Nearly linear relation is obtained between primary dendrite arm spacing and G^-0.4R^-0.2 in Fe-C alloy
as well as stainless and Cr-Mo steels.
2) Primary dendrite arm spacings in Fe-C and Fe-P alloys slightly increase as the solute content increases.
3) Primary dendrite arm spacings in Fe-0.5%C-P and Fe-0.5%C-S alloys are not affected by phosphorus and sulfur content.
4) The effects of the kind and amount of solute on primary dendrite arm spacing can be almost explained by Okamoto-Kishitake's equation in iron-base alloys as well as aluminium alloys.