A particular mould in which the directional solidification of the molten iron took place from the bottom to the top, was designed to produce similar solidification curves in the experimental cast blocks to those in the castings of actually required size.
The pealitic spheroidal graphite irons containing Ni, Cr or Mo were cast into the mould, and the influence of alloying elements on the mass effect of these irons was investigated in accordance with the metallographical technique as well as was the testing of mechanical properties.
Results obtained were as follows :
1) Solidification curves of molten irons in the mould, which were approximately 100kg were quite similar to those of cylindrical castings of safficient length, 600mm in diamener, when measured in the radial direction, that is the bottom of the mould corresponded to the surface of the cylindrical casting in the solidification curve and the top to the center.
It may be possible that the mould will be applied for the investigation of the mass effect in steel castings and in ordinary cast irons, as well as in spheroidal graphite irons.
2) Ni-Mo Spheroidal Graphite iron was least sensitive to the mass effect in the pearlitic spheroidal graphite irons investigated. Ni also improved the sensitivity to the mass effect of the pearlitic spheroidal graphite iron. But, Cr was less effective even added with Ni and Mo.
