• CN:11-2187/TH
  • ISSN:0577-6686

›› 2014, Vol. 50 ›› Issue (2): 116-124.

• 论文 • 上一篇    下一篇

钢锭模用灰铸铁服役工况下的组织与力学行为研究

兰鹏;李阳;原卓浩;张家泉;张瑞天   

  1. 北京科技大学钢铁冶金新技术国家重点实验室;北京科技大学冶金与生态工程学院;鞍钢附企综合企业公司
  • 发布日期:2014-01-20

Microstructure and Mechanical Behavior of Grey Cast Iron for Ingot Mould under Service Conditions

LAN Peng;LI Yang;YUAN Zhuohao;ZHANG Jiaquan;ZHANG Ruitian   

  1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing Angang Subsidiary Enterprise Company
  • Published:2014-01-20

摘要: 依据灰铁钢锭模的铸造工艺制作试样,通过试验手段,模拟其服役热历程,分析微观组织、力学行为与使用寿命的关系。重点考察不同热作用历程后铸铁的石墨基体与拉伸性能的变化规律。研究发现,珠光体灰铁试样在400 ℃附近存在抗拉强度随温度升高而增大的反常区,并认为这可能与预先热模拟处理后造成的内耗变化有关。试样经800 ℃保温3 h并控温冷却后,其600 ℃以下的抗拉强度可提高45%以上;同时,试样各温度下的抗拉强度均随热循环作用的次数(最多热循环处理50次)增加而减小,且这一现象在20次循环处理后尤为显著。基于光学显微镜、扫描电镜和能谱分析等表征手段,揭示其拉伸性能、变形行为与基体组织形貌的相关性,并探讨大型灰铁钢锭模的失效机制和合理使用工艺。

关键词: 铸铁;钢锭模;组织;力学行为

Abstract: The relationship between microstructure and mechanical behaviors of the grey iron specimens after various thermal histories, prepared based on the casting process of ingot mould, is studied. It is found that there is an abnormal temperature range near 673 K in which the tensile strength increases with temperature increasing, and it should be related to the internal friction variation resulted from the thermal pretreatment. The difference of microstructure and mechanical properties of as-cast and heat pretreated specimens is revealed, and that matches the mould failure status during ingot casting. From the experiment, it is shown that the tensile strengths of the specimens after keeping 1 073 K for 3 hours pretreatment are improved obviously at all test temperatures. Moreover, the tensile strengths of the specimens after cyclic thermal load drop with the numbers of the thermal cycle pretreatment increasing. The failure mechanisms of grey iron ingot mould and reasonable suggestions to improve its service life are proposed.

Key words: cast iron;ingot moulds;microstructure;mechanical behaviors

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