Q345B钢板材拉伸断口分层的机理  

Mechanism of delamination in tensile fracture of Q345B plate

作　　者：陈方玉[1] 邹德辉[2] 陈吉清[1] 

机构地区：[1]武汉钢铁(集团)公司研究院,湖北武汉430080 [2]武汉大学动力与机械学院,湖北武汉430072

出　　处：《钢铁研究》2010年第5期21-25,共5页Research on Iron and Steel

摘　　要：采用扫描电镜形貌观察配合能谱仪成分分析及组织评级方法,经过分析,得到层状断口的微观形貌、组织和成分特征。结果表明,层状断口与板材的带状组织有关,带状组织有铁素体和珠光体条带,另外还包括贝氏体、粗大的链状碳化物等异常组织。相邻带状组织因其力学性能上的差异,致使拉伸过程中形变不能协调,塑性差的组织条带因其形变滞后,早期发生断裂,出现微裂纹,裂纹沿着两组织界面扩展,逐渐发展成为层状形态。The micro-morphology, mierostructure and composition characteristics of lamellar fracture of Q345B plate were analyzed by SEM with energy spectrometer and microstructure ranking. The results showed that lamellar fracture is related to the banded structure of steel plate. The banded structure includes the bands of ferrite and pearlite, and also some abnormal microstructures such as bainite, massive chain shape carbide, etc. Because of differences of mechanical properties between the adjacent handed struc- tures, the deformation in tensile process can not be of coordination. Then the fracture occurs earlier in the worse plastic banded structure because of transformation hysteresis, i. e, micro-crack. The micro-crack extends with the interface of microstructure, then develops gradually into the lamellar shape.

关 键 词：拉伸 断口 分层 带状组织 偏析 贝氏体 碳化物 

分 类 号：TG115.22[金属学及工艺—物理冶金]