共晶灰铸铁的结晶动力学

发布时间：2018-04-24 15:08

本文选题：共晶灰铸铁 + 组织转变　；参考：《材料热处理学报》2017年04期

【摘要】：结合数字光学显微镜、扫描电镜(SEM)、高分辨三维X射线衍射、热分析和高温液淬的方法研究共晶灰铸铁的凝固过程和组织演变规律,深入分析石墨的长大动力学及三维连通特征。结果表明:共晶灰铸铁中的石墨结晶初始形貌为球状,异质形核核心为MnS,尺寸为1~2μm;共晶反应开始时石墨发生变异,长成细小片状石墨,并在共晶团内长大,随后相邻共晶团内的石墨通过中间的液相生长在一起,连接成更大的石墨,共晶反应结束时,大部分石墨在三维上连接在一起,连通率为88.87%;共晶灰铸铁结晶时,石墨长度与时间的关系为、L=-390.56+555.32(1-e~(-t/34.52)),石墨含量与时间的关系为、C=-17.24+27.02(1-e~(-t/41.57))。
[Abstract]:The solidification process and microstructure evolution of eutectic gray cast iron were studied by means of digital optical microscope, scanning electron microscope, high resolution 3D X-ray diffraction, thermal analysis and high temperature liquid quenching. The growth kinetics and three dimensional connectivity characteristics of graphite were analyzed. The results show that the initial morphology of graphite in eutectic gray cast iron is spherical, the core of heterogeneous nucleation is MNS, and the size is 1 ~ 2 渭 m. At the beginning of eutectic reaction, graphite changes, grows into fine flake graphite, and grows in eutectic cluster. Then the graphite in the adjacent eutectic cluster grows together through the intermediate liquid phase to form a larger graphite. At the end of the eutectic reaction, most of the graphite is connected together in three dimensions, with a connectivity of 88.87; when the eutectic gray cast iron crystallizes, The relationship between the length of graphite and time is as follows: LU -390.56 555.32 Ke / t / t / 34.52%, and the relation between graphite content and time is C ~ (-17.24) 27.24 ~ (-1) E ~ (1 /) -t / / 41.57 ~ (g) ~ (-1).
【作者单位】：西安工业大学材料与化工学院;北京特种车辆研究所;
【基金】：基金项目:高蠕化率蠕铁气缸盖成形技术研究(30105090201)
【分类号】：TG251

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