SPOFIC II - Shrinkage Porosity Formation in Compacted Graphite Iron, part 2.

Important results from the project

The aim of the project SPOFIC II is to identify formation mechanisms for shrinkage pores in compacted graphite iron (CGI). The final goal is that no pores causing decreased strength or in other ways disturbed function of cast components are formed. This final goal cannot be considered fulfilled, but the sub goals formulated can to a large extent. The theoretical work bring a lot of new knowledge, meaurements of iron density have been done in two ways and correlation between pore formation and production parameters is ongoing.

Expected long term effects

A reproducable method for manufacturing CGI throught remelting of ductile iron has been developed. Accurate studies of the samples from these method give by the use of EPMA deepened knowledge about segregation behaviour during solidification. This information may be used for alloy optimisation. Volume change measurements with the new instrument brings new knowledge about these anisotropical structures. This could lead to improved design practices. Data from dilatometer measurements give a better foundation for modelling.

Approach and implementation

The project activities were divided into four sub projects, A-D. Part A and most of Part B were done in laboratory environment. Part C is about calculation.This part was completely done by the participating university but unfortunatley still not finished due to a late recruitment of adequate competence. The rest of the project was performed by a close cooperation between the partners. Part D was very comprehensive. The huge amount of cast samples cannot be analysed during the project time.