Summary: | 碩士 === 逢甲大學 === 機械工程學所 === 95 === The purpose of this research is to study the effects of alloying parameter (alloying elements Cr, Cu, Sn and addition amount) and casting parameters (addition amount of nodulant, addition amount of inoculant, spheroidizing treatment temperature etc.,) on the mechanical properties (tensile strength, ductility, impact value and hardness) and metallographic microstructures (nodularity, nodule count, matrix, laminar structure thickness of pearlite etc.,) of FCD800-2 ductile cast iron.
The experimental results indicate that alloying and casting parameters have significant effects on mechanical properties and metallographic microstructure of FCD800-2. In alloying parameter, increasing the content of Cr, Cu and Sn to 0.6, 1.2 and 0.06%, respectively, all can enhance the tensile strength and hardness of FCD800-2 ductile cast iron. However FCD800-2 ductile cast iron with high impact value and elongation must be fabricated by decreasing the percentage of Cr, Cu and Sn to 0.3, 0.8 and 0.02%, separately. Moreover, FCD800-2 ductile cast iron made by adding Cr, Cu and Sn has significant fineness effect on laminar structure thickness of pearlite and correlation with the variation of mechanical properties.
In casting parameters, raising the addition amount of nodulant and inoculant and pouring temperature all can elevate tensile strength and nodularity of FCD800-2 ductile cast iron.
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