METALLURGICAL PARAMETERS, MECHANICAL-PROPERTIES AND MACHINABILITY OF DUCTILE CAST-IRON

Results on the effect of solidification cooling rate on the microstruc ture, mechanical properties and machinability of spheroidal graphite ( SG) iron have been presented. The effect of ferritic heat treatment on the same properties has been also investigated. The microstructural o bservation, tensile properties and hardness values of the present SG i ron has been developed. The tool life criterion was used as a measure of machinability. It was found that during turning of SG iron by using a single point cutting tool, its life increased with decreasing the s olidification cooling rate for both sand and metal moulds. The tool li fe was found to be significantly affected by the variation of nodule c haracteristics. A decrease in tool life due to an increase of nodule c ount was observed. The tool life was found to be directly proportional to the ductility of SG iron whether for the as cast or ferritic heat- treated ingots.