The aim of this thesis is to find an additional method to determine the quality of FeSiMg alloy as nodulating agent. We have selected two materials comparable by chemical analysis and with the help of optical and electronic microscopy we have searched for possible differences, which we are not yet able to perceive with the established methods of incoming inspection in the company WIRE d.o.o. Based on the experience of the employees, the results of the comparisons of our and competing wires and the differences in the efficiency of our wires using comparable fillers from different suppliers, a hypothesis was made about the influence of the microstructure on the final efficiency.
The hypothesis of the influence of the homogeneity of the phase distribution on the quality of the alloy as a wire filler attempts to present uniformly the total influence of all mixing, casting and crushing parameters present in the filler production. Due to the importance of correct sieve analysis and its possible correction, samples of both materials were sieved into different size classes. The preparation of metallographic samples and optical and electronic microscopy were performed at University Center for Electron Microscopy (UCEM) at the University of Maribor. Metallographic images were taken, phase identification was performed and the degree of homogeneity was determined. The two materials showed a significant difference in the degree of homogeneity, and a clear dependence of homogeneity on particle size class within each material was also found. The results of the thesis will be verified in future trials in foundries producing ductile iron using a wire nodule process.
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