合金碳化物M_(23)C_(6)对CLAM钢晶界拉伸性能的影响机理研究  

Mechanism of alloy carbide M_(23)C_(6)influencing grain boundary tensile behaviour of CLAM steel

作　　者：谢亚飞 侯廷平 于涛[4] 程石[1,2,3] 陈梦军 吴开明 Xie Yafei;Hou Tingping;Yu Tao;Cheng Shi;Chen Mengjun;Wu Kaiming(Hubei Province Key Laboratory of System Science in Metallurgical Process,Wuhan University of Science and Technology,Wuhan 430081,China;State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Collaborative Innovation Center for Advanced Steels,Wuhan University of Science and Technology,Wuhan 430081,China;School of Optoelectronic Materials and Technology,Jianghan University,Wuhan 430056,China)

机构地区：[1]武汉科技大学冶金工业过程系统科学湖北省重点实验室,湖北武汉430081 [2]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [3]武汉科技大学高性能钢铁材料及其应用省部共建协同创新中心,湖北武汉430081 [4]江汉大学光电材料与技术学院,湖北武汉430056

出　　处：《武汉科技大学学报》2023年第6期409-417,共9页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金项目(12174296,U1532268,U20A20279);湖北省重点研发计划项目(2021BAA057);江汉大学校级科研项目(2021yb026);湖北省高等学校优秀中青年科技创新团队项目(T201903);湖北省自然科学基金一般面上项目(2022CFB474);“111计划”项目(D18018)。

摘　　要：低活化马氏体-铁素体钢是目前核聚变反应堆的首选结构材料之一,钢中纳米级碳化物析出相对其韧塑性能起关键作用。本文以CLAM钢为研究对象,利用SEM、TEM对其显微组织、碳化物析出相M23C6(M=Fe,Cr)相及断裂微区进行表征与分析。结果表明,M_(23)C_(6)主要分布在马氏体板条边界,在拉伸过程中会造成位错缠结堆积,促发微裂纹的萌生和扩展。为了从原子尺度上探究碳化物对晶界变形行为的影响,采用分子动力学方法模拟了拉伸变形过程中晶界(∑5(031))上碳化物和位错的交互作用。模拟结果显示,晶界的塑性变形以位错滑移和非晶化塑性变形为主。随着碳化物尺寸增大和数量增多,非晶化塑性变形程度增强,位错运动受阻,造成局部结构应力集中并产生微裂纹。Low-activation martensitic-ferritic steels are currently one of the preferred structural materials for nuclear fusion reactors,and the precipitation of nano-scale carbides plays a crucial role in the steel toughness and plasticity.By employing SEM and TEM,the microstructure,carbide precipitate phase M_(23)C_(6)(M=Fe,Cr),and the fracture microzone of the CLAM steel were characterized and analyzed.The results indicate that carbide M_(23)C_(6)primarily distributes along the martensitic lath boundaries,inducing dislocation tangle accumulation during tensile deformation,which promotes the nucleation and propagation of microcracks.To explore the effects of carbides on grain boundary deformation behavior at the atomic scale,molecular dynamics simulations were conducted to examine the interaction between carbides and dislocations during tensile deformation at the grain boundary(∑5(031)).The simulation results reveal that plastic deformation at the grain boundary predominantly occurs through dislocation slip and amorphization.As the size and quantity of carbides increase,the extent of amorphous plastic deformation at the grain boundary intensifies,impeding dislocation movement,leading to localized structural stress concentration and the generation of microcracks.

关 键 词：CLAM钢 碳化物 M_(23)C_(6) 晶界 分子动力学 塑性变形 

分 类 号：TL341[核科学技术—核技术及应用] TG142.73[一般工业技术—材料科学与工程]