微观缩松对蠕铁微观组织和力学性能的影响

发布时间：2018-07-20 09:10

【摘要】：微观缩松缺陷的位置分布、体积大小表现出随机性特点,会对材料微观组织和宏观力学性能产生影响.通过微观组织观测,研究了微观缩松对蠕墨铸铁材料微观组织的影响.同时,建立了含微观缩松缺陷的三维代表性体积元模型,通过施加周期性边界条件和拉伸位移载荷,研究了微观缩松对蠕墨铸铁材料宏观力学性能的影响.结果表明,蠕铁材料微观缩松缺陷周围组织中含有Ce,Mg元素,表明稀土蠕化剂与所研究的蠕墨铸铁的微观缩松的形成有密切联系,增加了材料内部形成微观缩松的倾向.随着材料内部微观缩松体积分数的增加,材料的宏观等效弹性模量呈线性降低;微观缩松还会造成材料内局部区域的应力集中,易于微小裂纹的萌生及扩展.
[Abstract]:The location distribution and volume size of the shrinkage defects are random, which will affect the microstructure and macroscopic mechanical properties of the materials. The effect of shrinkage on microstructure of vermicular graphite cast iron was studied by observation of microstructure. At the same time, a three-dimensional representative volume element model containing micro-shrinkage defects was established. The effect of micro-shrinkage on the macroscopic mechanical properties of vermicular graphite cast iron was studied by applying periodic boundary conditions and tensile displacement loads. The results show that the microstructure of vermicular iron material contains mg element, which indicates that the rare earth compaction agent is closely related to the formation of microscopic shrinkage of vermicular graphite cast iron studied, and increases the tendency of micro shrinkage in the material. The macroscopic equivalent elastic modulus of the material decreases linearly with the increase of the volume fraction of the microscopic shrinkage in the material, and the micro-shrinkage will also cause the stress concentration in the local region of the material, and it is easy for the initiation and propagation of micro-cracks.
【作者单位】：北京理工大学机械与车辆学院;河南科技大学材料与工程学院;
【基金】：国家“九七三”重点基础研究发展规划资助项目(6131460303)
【分类号】：TG143.49

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