A Study of the Relationship between Cooling Curves and Microstructures of the Heavy-Section Ductile Cast Iron

• Main Authors: Ching- Lung Chen, 陳慶隆
• Other Authors: Tien-Shou Lei
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/32994711829730767129

碩士 === 國立臺灣科技大學 === 機械工程系 === 88 === This paper studied the effect of size of heavy section of ductile cast iron, with unidirectional solidification, on the casting quality. The experiment data of the local solidification times were correlated with the fading tendency of the nodular graphite. The experimental results indicate that degenerated forms of the graphite tend to form in heavy section ductile iron castings which solidify over an extended period of time. It shows strong relationship between structure of graphites and the cooling curve of that casting. With the addition of heat generating powder on the riser top after pouring, a condition of unidirectional solidification was built, which reduced the volume shrink and then resulted in a sound casting. In this paper, the data of experiment of local solidification times were presented. The inoculant, heat generating power, size section, and over-heating are the main factors which will effect the solidification times.