METHODOLOGY FOR DETERMINATION OF DEGREE OF NODULARITY IN A DUCTILE CAST IRON GGG 40 BY ULTRASONIC VELOCITY TEST

Cast iron alloys combine many elements such as carbon, iron, silicon, magnesium and can be usually classified according to their microstructure in ductile, gray, compacted, white, and malleable. Each one has particularities in terms of properties and applications. Hence, this study aims to evaluate the degree of nodularity (%) in a ductile cast iron alloy GGG 40. In this context, a methodology to investigate the degree of nodularity was proposed. The ultrasonic method was used to determine the amount of ductile graphite as well as for parts release and thus facilitated the industrial operational execution. The effect of ultrasonic sound was investigated in sixty-seven ductile cast irons, and these analyses were further compared to the level of nodularity observed by metallography. Finally, based on the findings, the cast iron quality was guaranteed, leading to time savings, avoiding the microstructural examination, and thus promoting cost reductions.