摘要
采用光学与电子显微术研究了一种低碳微合金钢中充分细化的板条贝氏体组织的室温变形行为,分析了拉伸变形样品中未变形区、均匀变形区与缩颈区的组织形态差别。实验表明:未变形区与均匀变形区中各束板条的空间取向(板条长轴的指向)基本是随机的;但在缩颈区,所有板条接近平行于拉伸轴向,说明某些板条在拉伸过程中发生了大角度的转动,这一现象不能单由晶体学得到解释。通过与另外两组不同组织形态样品的对照比较,发现板条转动程度与板条长度以及长宽比密切相关。据此提出板条界面阻碍位错运动导致可动滑移系的自然选择与板条连续转动的机制。
Optical examination and transmission electron microscopy were employed to investigate deformation behavior of ultra-fine lath-like bainite in a low carbon microalloyed steel at room temperature. Microstructures of undeformed part, uniformly deformed part and necking part of sample subjected to mono-axis tension were compared. It was found that the orientations of lath sheaves (represented by axis direction of laths) in undeformed part and uniformly deformed part are nearly random while the orientations of almost all laths are parallel,to tension direction in necking part. It indicates that some laths have turned considerably large angle during tension, which is a phenomenon difficult to be explained by crystallography. By contrasting with other samples, it is revealed that the scale of lath turning is related to the length and the ratio of length to width of laths. A mechanism involving natural selection of practically movable slip system and continuously turning of laths due to inhibition of lath boundaries to motion of dislocation was proposed.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第6期579-584,共6页
Acta Metallurgica Sinica
基金
国家重点基础研究发展规划项目 G1998061507资助
关键词
低碳微合金钢
板条状组织
拉伸变形
low carbon microalloyed steel
lath-like microstructure
tensile deformation
