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Ductile iron is cast iron with spheroidal graphite. This material has a very high strength (similar to that of steel). The material is therefore used in many industrial sectors - and also, for example, in the automotive industry for the production of vehicle parts.
One component of the module CastIronAnalysisis the graphite evaluation ofductile iron (GJS). According to the standard, the determination of the parameters graphite size, graphite shape and nodularity a significant role.
According to the standard, the graphite size is understood to be the maximum length of a particle and thus the diameter of the circle circumscribing it. The analysis result determined by the software is displayed as a size class histogram, which takes into account the reference number sizes of the selected standard accordingly.
The evaluation of the shape is carried out by means of a special classifier, which analyzes the roundness, compactness and convexity of individual graphite particles, and assigns them to the shape classes (I – IV) .
Nodularity is a parameter that is not explicitly described either in the DIN EN 945 standard or in ASTM A247. Nevertheless, it is closely related to the evaluation of cast structures and is therefore increasingly demanded by customers as a parameter. The nodularity is used to characterize the deviation of the spherulitic structure from the spherical shape.
Due to the exact analysis of the different graphite shapes, not only degenerations or deviations from the spherical shape can be determined, but also an application to various other cast iron materials is possible. For example, the degree of degeneracy is constantly increasing as scrap made from increasingly high-grade alloys is used, and accurate assessment is therefore becoming more and more important.
Furthermore, this program can be used in the same way for the examination of vermicular graphite (GJV). In this respect, the determination of the nodularity index describing the sample plays a particularly important role.