渗碳体形态对珠光体钢丝拉拔形变的影响  

Effect of cementite morphology on pearlitic wire drawing deformation

作　　者：胡显军 谢骏 周立初 王雷 方峰[2] HU Xian-jun;XIE Jun;ZHOU Li-chu;WANG Lei;FANG Feng(Institute of Research of Iron and Steel of Shasteel, Zhangjiagang 215625, Jiangsu, China;School of Materials Science and Engineering, Southeast University, Nanjing 211189, Jiangsu, China)

机构地区：[1]江苏省(沙钢)钢铁研究院,江苏张家港215625 [2]东南大学材料科学与工程学院,江苏南京211189

出　　处：《钢铁研究学报》2018年第2期120-126,共7页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(51371050);江苏省产学研前瞻性研究项目(BY2016076-08);江苏省科技成果转化项目(BA2017112)

摘　　要：利用金相显微镜、扫描电镜、透射电镜、拉伸试验机、硬度计对比研究了渗碳体分别为层片状与球状时对珠光体钢丝拉拔形变过程和性能的影响。层片状渗碳体在拉拔形变过程中表现出一定的变形能力,随应变量的增加,层片状珠光体逐渐演变为纤维状,且组织中未发现明显缺陷。球状渗碳体在形变过程中自身并不发生变形,但会向拉拔方向转动,并在渗碳体/铁素体的两相界面处出现微观缺陷,而这与球状渗碳体钉扎位错引起的应力集中有关。2种珠光体钢丝的强度和硬度均随着拉拔应变量的增加而不断提高,层片状珠光体的拉拔硬化率更高。随着拉拔的进行,钢中开始形成〈110〉织构。与球状珠光体相比,层片状珠光体组织的〈110〉织构强度更强,且随着应变量的增大,二者织构强度差越来越大。A comparative study was conducted on the effects of lamellar cementites and globular cementites on the cold drawing process and the mechanical properties of pearlitic wire steel,with the help of metallographic microscope,scanning electron microscope,transmission electron microscope,tensile tester and hardness tester.The lamellar cementites showed the deformation capacity to some extent during the cold drawing process.As the drawing strain increased,the pearlitic wire with globular cementites evolved into the fibrous form gradually and no obvious defects were found in the microstructure.The globular cementites turned to the drawing direction without any deformation of itself during the deformation process.And micro-cracks occurred in the cementite/ferrite interface due to stress concentration caused by pinning dislocations in spherical cementites.The strength and hardness of both pearlitic wires gradually increased as the drawing strain rose.And the pearlitic wire with lamellar cementites had a higher drawing hardening rate.The ferrite 〈110〉 texture formed in both pearlitic wires during the cold drawing process.Compared with the globular pearlite,the pearlitic wire with lamellar cementites had higher ferrite〈110〉texture intensity.And the difference of their ferrite〈110 〉texture intensity became bigger and bigger as the drawing strain increased.

关 键 词：渗碳体 珠光体钢丝 拉拔形变 

分 类 号：TG142.1[一般工业技术—材料科学与工程]