Melt Stirring of Nodular Cast Iron

Abstract:

In this work the effects of stirring/vigorous shearing on matrix and graphite phase in nodular cast iron melt during solidification were studied. Several experiments were conducted for different cooling and stirring times. Samples were prepared and examinations of the microstructure were conducted and compared using Leica Optical Microscope and Scanning Electron Microscope (SEM). In addition, a chemical analysis of the graphite precipitate was performed using EDX equipment mounted on SEM. Oxidation of the melt and formation of oxide nuclei during stirring were observed and analysed. The influence of melt shearing on the structure, nodule count, distribution, area fraction and on overall graphite precipitation was observed and examined with the help of respective computer programs and soft wares. Stirring resulted in increasing the nucleation sites for graphite precipitation thereby increasing the nodule count and area fraction of carbide and transforming the structure from pearlitic matrix to ferritic matrix.

• Periodical: Materials Science Forum (Volume 925)
• Pages: 125-132
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.925.125
• Online since: June 2018
• Authors: Fareed Ashraf Khan*, Hasse Fredriksson
• Keywords: Ductile Cast Iron, Formation of Graphite Strings, Melt Shearing, Melt Stirring, Nodular Cast Iron, Nodule Count, Nodule Distribution, Nucleation in Cast Iron, Oxidation of Melt, Turbulent Flow of Melt

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