| 摘要: |
| 采用OM、SEM、EBSD及TEM对25CrMo钢的微观组织进行定量表征，分析微观组织对试验钢塑性的控制作用。结果表明：随着晶粒的粗化，低碳板条马氏体钢的塑性逐渐增加，其与传统的理解不同，即具有大角度取向的原奥氏体晶粒(也包括束和块)不再是塑性的协调单元.只有属于小角度取向的马氏体板条对塑性的影响满足细晶增塑的原理，即在低碳板条马氏体钢中板条是塑性的有效控制单元.因此，在板条马氏体钢中，细化马氏体板条或增加小角度界面比例，是提高塑性的重要途径，其弥补了细化晶粒在大型构件中难以实现的不足.此外，也为高强度、高塑性材料的设计和开发提供了新思路.
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| 关键词: 25CrMo钢 原奥氏体晶粒 亚结构 取向 塑性 |
| DOI：10.11951/j.issn.1005-0299.20180053 |
| 分类号:TG142.2 |
| 文献标识码:A |
| 基金项目:贵州省科技厅科技支撑计划项目(黔科合［2007］2006). |
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| The coordination unit and optimization investigation of the plasticity of 25CrMo axle steel |
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QU Pengju
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(Engineering training center ,Guizhou Institute of Technology, Guiyang 550003, China)
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| Abstract: |
| In this paper, the microstructure of 25CrMo steel was characterized quantitatively by means of OM, SEM, EBSD and TEM. Effect of the microstructure on the tensile properties was discussed. Results indicated that the plasticity of the tested steel increased with the increase of prior austenite grain, which is different from traditional understanding, namely, prior austenite grain (containing packet and block)with high angle boundaries is not the coordination unit of plasticity. However, only the effect of martensitic lath with low angle boundaries on the plasticity met the plasticizing mechanism for the refining grain, i.e., the martensitic lath is the coordination unit of the plasticity in low carbon lath martensite steel. Therefore, the refining of martensite lath or the growth of the low angle orientation is an important method to promote the plasticity in lath martensite steel. It also makes up for the disadvantage that it is difficult to obtain refining grain in large structure. Besides, it provides a new perspective for the design and development of material with high strength and high plasticity.
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| Key words: 25CrMo steel prior austenite grain sub-structure orientation plasticity |
