ABSTRACT A procedure and specification for evaluating the degree of spheroidization of graphite in spheroidal graphite iron (SGI), using a computer-based image analyzing system has been developed as an aid to structure-property-quality assessment. Both global and feature-specific numerical indices have been programmed and implemented using a Zeiss Jenaphot 2000 projection microscope and SEM interfaced to a computer-based MACROS III analyzer and a CCD video camera. The modular procedure has been tested and used to evaluate the effect of variation in the degree of spheroidization of graphite on the 0.2 % offset yield strength for an iron series ranging from ASTM type I (fully nodular) to ASTM type II-III-IV (mixtures of nodular and compacted/vermicular graphite) and were found to indicate
Cite this paper
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