Why can't cast iron be poured

In contrast to the sand casting process, in which the casting molds are destroyed after casting to remove the cast part, permanent metallic molds (molds = French shell), for example made of cast iron or steel, can be used again for the next casting after the casting has been removed. Larger series can also be produced economically in this way.

In addition to simple geometries, such as B. cuboids or bushes, even complicated geometries can be produced in the chill casting through the use of mold slides, inserts and sand cores.

When designing the structure, care must be taken that the shrinkage and shrinkage during solidification are not hindered so that the casting cannot shrink out onto the mold and remain removable. Sharp edges and small radii should be avoided as far as possible in order to avoid the formation of a hardening structure on the sharp edges because of the high cooling rate in the metallic mold.

The high cooling speed creates a very fine structure with a higher number of smaller eutectic cells compared to casting in sand-bound molds. The solidification can be adjusted within wide limits to the requirements of the cast part by appropriate cooling or heating of the mold areas concerned.

In the case of spheroidal graphite cast iron (EN-GJS), the chill casting has better elongation and impact strength values ​​as well as a very high level of tightness due to the finely distributed balls. The basic structure can be ferritic, ferritic-pearlitic and pearlitic. The cast parts are generally subjected to a heat treatment in order to achieve the desired structural condition (picture 3).