Analysis of Solidification Microstructure and Cell Boundary Precipitates of Si Solution Strengthened Ferritic Ductile Iron
Author of the article:ZHAI Qiuya;QUAN Zhen;XU Jinfeng;ZHAO Xinwu;HE Baolou
Author's Workplace：School of Materials Science and Engineering,Xi'an University of Technology,Xi'an 710048,China;Xixia Intermal Combustion Engine Intake and Exhaust Pipe Co.,Lud.,Xixia 474500,China
Key Words：silicon solution strengthening ferritic ductile iron solidification structure cell boundary precipitate phase
Abstract：Si solution strengthened ferritic ductile iron is a kind of engineering material with simple production process and excellent properties. The solidification microstructure evolution and common precipitates at eutectic cell boundary of Si solution strengthened ferritic ductile iron in a wide range of silicon content were studied by means of coloring etching method. The results show that solidification structure of Si solution strengthened ferritic ductile iron is composed of eutectic cells( graphite + austenite) and a small of amount of halo dendrite original from austenite shell. With the increased carbo equivalent,the nodularity,nodule count,nodule size and the number of halo dendrites decreased. At the end of solidification,the residual liquid is rich in Ti,Mo,Mn,Cr and O elements. At last solidification,a small amount of amorphous alloy carbides,oxides and ferrsilicate compounds are formed.
