Carbon Redistribution Process in Austempered Ductile Iron (ADI) During Heat Treatment—APT and Synchrotron Diffraction Study
Carbon Redistribution Process in Austempered Ductile Iron (ADI) During Heat Treatment—APT and Synchrotron Diffraction Study
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DOI：
10.3390/met9070789
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发表时间：
2019-07
期刊：
影响因子：
2.9
通讯作者：
Xiaohu Li;J. N. Wagner;A. Stark;R. Koos;M. Landesberger;M. Hofmann;G. Fan;W. Gan;W. Petry
中科院分区：
文献类型：
--
作者：
Xiaohu Li;J. N. Wagner;A. Stark;R. Koos;M. Landesberger;M. Hofmann;G. Fan;W. Gan;W. Petry
利用同步辐射衍射和原子探针层析技术（APT）研究了等温淬火过程中碳在球墨铸铁中的扩散和再分布过程。定量测定了不同等温温度下贝氏体铁素体中碳含量的变化过程。ADI中的转变由过饱和铁素体的脱碳和碳化物沉淀控制，并且根据Takahashi和Bhadeshia为贝氏体钢开发的模型，发现其分为三个阶段。APT明确地确定了等温淬火后铁素体中碳化物和碳团的形成、形态和组成。最后，用经验公式表达了ADI合金中铁素体中碳含量、碳间隙值和等温淬火温度之间的关系。
In-situ synchrotron diffraction and atom probe tomography (APT) have been used to study the carbon diffusion and redistribution process in austempered ductile iron (ADI) during austempering. The process of carbon content change in bainitic ferrite during different austempering temperatures has been determined quantitatively. The transformation in ADI is controlled by decarburization of supersaturated ferrite and carbide precipitation and has been found to be divided into three stages based on a model developed for bainitic steels by Takahashi and Bhadeshia. The formation, morphology and composition of carbides and carbon clusters in ferrite after austempering have been identified unequivocally by APT. Finally, the relationships of carbon content in ferrite, carbon gap values, and austempering temperatures in the ADI alloy were expressed using empirical equations.