Microstructure evolution in grey cast iron during directional solidification

作     者：Xian-fei Ding Xiao-zheng Li Qiang Feng Warkentin Matthias Shi-yao Huang 

作者机构：National Center for Materials Service Safety University of Science and Technology Beijing Beijing Key Laboratory of Special Melting and Preparation of High-end Metal University of Science and Technology Beijing State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Ford Research & Advanced Engineering Europe Materials and Process Research Ford Motor Research and Engineering Center 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2017年第24卷第8期

页      面：884-890页

核心收录：

学科分类：080503[工学-材料加工工程] 0709[理学-地质学] 0819[工学-矿业工程] 0806[工学-冶金工程] 08[工学] 0708[理学-地球物理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 080201[工学-机械制造及其自动化] 

基　　金：The financial support provided by Ford Motor Company (University Research Program) 

主　　题：directional solidification grey cast iron phase transition graphite 

摘      要：The solidification characteristics and microstructure evolution in grey cast iron were investigated through Jmat-Pro simulations and quenching performed during directional solidification. The phase transition sequence of grey cast iron was determined as L → L + γ→ L + γ + G →γ + G → P(α + Fe_3C) + α + G. The graphite can be formed in three ways: directly nucleated from liquid through the eutectic reaction(L →γ + G), independently precipitated from the oversaturated γ phase(γ→γ + G), and produced via the eutectoid transformation(γ→ G + α). The area fraction and length of graphite as well as the primary dendrite spacing decrease with increasing cooling rate. Type-A graphite is formed at a low cooling rate, whereas a high cooling rate results in the precipitation of type-D graphite. After analyzing the graphite precipitation in the as-cast and transition regions separately solidified with and without inoculation, we concluded that, induced by the inoculant addition, the location of graphite precipitation changes from mainly the γ interdendritic region to the entire γ matrix. It suggests that inoculation mainly acts on graphite precipitation in the γ matrix, not in the liquid or at the solid–liquid front.