2. Factors influencing properties

2.1 Microstructure

In spheroidal graphite cast irons, the graphite is in a compact form close to a sphere (figure 1 ). The V and VI forms defined by standard NF EN ISO 945, which are encountered industrially, have little influence on the mechanical properties of these cast irons.

The difference between the various grades specified in standard NF EN 1563 of October 1997 (see table 1 ) lies in the nature of the metal matrix surrounding the...