摘要
低温辐照脆化是影响低活化铁素体/马氏体(RAFM)钢服役的主要问题之一。RAFM钢低温辐照脆化的主要机理是辐照产生的纳米缺陷(如位错环、析出物等)阻碍位错运动。本文利用分子动力学方法研究了bcc-Fe内刃型位错线与1/2〈111〉间隙位错环的相互作用,并对比分析了Cr偏析在位错环上对其硬化的影响。研究结果表明:刃型位错线挣脱位错环所需临界剪切应力(CRSS)与位错环的伯格斯矢量有关;在本文所研究条件下,在一定温度范围内,Cr偏析在位错环上会使得位错线挣脱所需CRSS增加,引起硬化增强。
Lower temperature irradiation embrittlement is one primary issue limiting the use of reduced activation ferritic/martensitic(RAFM) steels. The primary mechanism of lower temperature irradiation embrittlement is the obstruction of dislocation motion by nano-metric defects, such as dislocation loop and precipitation, induced by irradiation. Using molecular dynamics, the interaction mechanism between edge dislocation line and 1/2〈111〉 interstitial dislocation loop in bcc-Fe was studied, and the effect of Cr segregation at interstitial dislocation loop on irradiation hardening was analyzed. The results show that the critical resolved shearing strain(CRSS) for dislocation line to break away from loop is related with the Burgers vector(BV) of loop. Under the condition studied here, within a certain temperature range, Cr segregation at loop increases the CRSS for dislocation line to break away, thus enhances hardening.
作者
贾丽霞
贺新福
吴石
曹晗
王东杰
豆艳坤
杨文
JIA Lixia;HE Xinfu;WU Shi;CAO Han;WANG Dongjie;DOU Yankun;YANG Wen(Division of Reactor Engineering Technology Research ,China Institute of Atomic Energy, Beijing 102413, China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2019年第3期458-464,共7页
Atomic Energy Science and Technology
基金
国家自然科学基金资助项目(11375270
11575295)
关键词
RAFM钢
低温辐照脆化
位错环
Cr偏析
分子动力学
reduced activation ferritic/martensitic steel
lower temperature irradiation embrittlement
dislocation loop
Cr segregation
molecular dynamics
