The graphite microstructure of Compacted Graphite Irons is expressed in terms of Percent Nodularity. For simultaneous optimisation of mechanical properties, castability, machinability and thermal conductivity, the graphite should be controlled within 0-20% nodularity specification range (more than 80% of the graphite particles must be in the compacted/vermicular form) in all performance-critical sections of the casting. Flake graphite is not permitted.
The %Nodularity and ferrite/pearlite matrix structure can be evaluated by the chart comparison technique or by image analysis. Both techniques are available from SinterCast. The SinterCast CGI Microstructure Rating Chart can be ordered via the following link:
- Order (Poster size: 1,000 x 700 mm). EUR 45.00 plus postage and handling.
CGI Image Analysis Software
The SinterCast microstructure rating technique has been adopted by the ISO 162112 international standard for Compacted (Vermicular) Graphite Iron. SinterCast has also developed software macros for CGI image analysis according to the ISO 16112 rating technique. These macros are compatible with Image Pro Plus image analysis software and are available to all SinterCast customers. Please Contact SinterCast to discuss the software macros.