Thermo-Mechanically Processed Multi-Phase Ductile Iron: Microstructure Development
Thermo-Mechanically Processed Multi-Phase Ductile Iron: Microstructure Development
复制标题
热机械加工多相球墨铸铁：微观结构开发
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Nofal
中科院分区：
文献类型：
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作者：
M. Soliman;H. Palkowski;A. Nofal
使用配备有硬度测量系统的热机械模拟器，通过在单个加工链中结合良好定义的变形过程和随后的控制冷却来加工具有不同Mn含量的两种球墨铸铁合金，以控制最终的显微组织。相应地，可得到马氏体、奥氏体铁素体、马氏体+铁素体和奥氏体铁素体+铁素体四种不同组织的球墨铸铁。根据电阻率测量结果，确定了两种合金的铁素体形成温度范围。在冷却过程中，观察到在石墨球处奥氏体优先转变为铁素体。还观察到，在冷却过程中铁素体的形成导致未分解奥氏体的马氏体开始降低和奥氏体铁素体形成的动力学加速。
Using thermo-mechanical simulator equipped with dilatometry system, two ductile iron alloys with different Mn-content are processed by combining both, well defined deformation process and subsequent controlled cooling in a single processing chain to control the final microstructure. Accordingly, ductile irons with four different structrues are produced namely, martensite, ausferrite, martensite+ferrite and ausferrite+ferrite. Depending on the dilatometric measurments, the ferrite formation temperature-range has been defined for both alloys. Preferential transformation of austenite to ferrite at graphite nodules during cooling is observed. It is also observed that the formation of ferrite during cooling results in both decreased martensite start of the undecomposed austenite and accelerated kinetics of ausferrite formation.