Fracture Characteristics of Fully Pearlitic Steel Wire in Tension and Torsion  

作　　者：Tian-zhang ZHAO Guang-liang ZHANG Shi-hong ZHANG Ling-yun ZHANG 

机构地区：[1]Key Laboratory of Fundamental Science for National Defence of Aeronautical Digital Manufacturing Process,Shenyang Aerospace University [2]School of Mechanical Engineering,Taizhou University [3]Institute of Metal Research,Chinese Academy of Sciences

出　　处：《Journal of Iron and Steel Research International》2016年第11期1206-1212,共7页

基　　金：Item Sponsored by National Natural Science Foundation of China(51034009,51404158);Doctoral Initiation Foundation of Liaoning Province of China(201601176)

摘　　要：The fracture characteristics of fully pearlitic steel wires with fine and randomly oriented lamellae have been investigated after tension and torsion, respectively. It is found that the predominant fracture mode under small pre- deformation is dimple. The analysis of the colony size and the lamellar structure near the fracture surface indicates that each dimple roots from one colony. A simulation of tensile deformation with several pearlitic colonies based on the real scanning electron microscopy （SEM） observation shows that the plastic deformation concentrates and the stress t^hxialit~＂ is larger ~it the boundaries bf colonies. It demonstrates the microe/＇a^ks initialize at colony boundaries. Thus, the colony size is a significant factor for fracture behaviors under small pre-deformation. On the other hand, the fracture surface is investigated after large pre-deformation via torsion. The results show that fracture characteristics vary with radius from dimples, elongated dimples to the fibrous structure. It indicates that the fracture charac-teristics are dependent on the pre-deformation. The fracture mode under large pre-deformation becomes an anisotropic fibrous structure instead of dimples.The fracture characteristics of fully pearlitic steel wires with fine and randomly oriented lamellae have been investigated after tension and torsion, respectively. It is found that the predominant fracture mode under small pre- deformation is dimple. The analysis of the colony size and the lamellar structure near the fracture surface indicates that each dimple roots from one colony. A simulation of tensile deformation with several pearlitic colonies based on the real scanning electron microscopy （SEM） observation shows that the plastic deformation concentrates and the stress t^hxialit~＂ is larger ~it the boundaries bf colonies. It demonstrates the microe/＇a^ks initialize at colony boundaries. Thus, the colony size is a significant factor for fracture behaviors under small pre-deformation. On the other hand, the fracture surface is investigated after large pre-deformation via torsion. The results show that fracture characteristics vary with radius from dimples, elongated dimples to the fibrous structure. It indicates that the fracture charac-teristics are dependent on the pre-deformation. The fracture mode under large pre-deformation becomes an anisotropic fibrous structure instead of dimples.

关 键 词：FRACTURE pearlitic steel wire tension TORSION 

分 类 号：TG356.45[金属学及工艺—金属压力加工]