选区激光熔化成形的304L不锈钢的Xe离子辐照损伤研究  

Damage characteristics of selective laser melted 304L stainless steel under Xe ion irradiation

作　　者：李莹 李健健[2] 付崇龙 白菊菊 侯娟 林俊[2] 戴志敏[2] LI Ying;LI Jianjian;FU Chonglong;BAI Juju;HOU Juan;LIN Jun;DAI Zhimin(School of Materials Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]上海理工大学材料科学与工程学院,上海200093 [2]中国科学院上海应用物理研究所,上海201800

出　　处：《核技术》2021年第7期9-16,共8页Nuclear Techniques

基　　金：国家自然科学基金(No.11605272);中国科学院前沿重点项目(No.QYZDY-SSW-JSC016);中国科学院战略性先导科技专项(No.XDA02030200)资助。

摘　　要：采用5 MeV的Xe离子在550℃对选区激光熔化成形(Selective Laser Melted,SLM)的304L不锈钢进行辐照,通过透射电子显微镜(Transmission Electron Microscopy,TEM)和纳米压痕仪分别研究了该材料辐照前后的微观结构和纳米硬度的变化,并在相同实验条件下与传统工艺轧制的(Traditionally Manufactured,TM)304L不锈钢进行对比。结果表明:SLM 304L和TM 304L不锈钢的位错环平均尺寸分别为(2.13±0.53)nm和(1.94±0.46)nm,对应的位错环数密度分别为1.48×10^(22) m^(-3)和6.94×10^(22) m^(-3);其Xe泡的平均尺寸分别为(3.71±1.40)nm和(1.37±0.46)nm,对应的Xe泡数密度分别为3.50×10^(22) m^(-3)和1.73×10^(23) m^(-3)。SLM 304L不锈钢位错环和Xe泡的数密度均低于TM 304L不锈钢,其Xe泡的平均尺寸约为TM 304L不锈钢的3倍。辐照后样品均出现了硬化现象,SLM 304L和TM 304L不锈钢的辐照硬化程度分别为14%和32%。通过弥散强化模型(Dispersed Barrier Hardening,DBH)计算辐照缺陷对材料硬化的影响,结果表明:位错环和Xe泡是导致材料硬化的主要因素。[Background]Owing to its excellent mechanical properties and corrosion resistance,304L stainless steel is widely used as the core structure material in advanced nuclear power systems.[Purpose]This study aims to investigate the damage characteristics of selective laser melted(SLM)304L stainless steel under Xe ion irradiation and compare them with that of traditionally manufactured(TM)304 stainless steel under the same experimental conditions.[Methods]SLM 304L and TM 304L alloy samples were irradiated with 5 MeV Xe ions at 550℃.The irradiation dose was 3.53×1015 ions•cm-2.The microstructure and nano-hardness changes of the both alloy samples before and after irradiation were characterized by transmission electron microscopy(TEM)and nanoindentation,respectively.TEM samples were prepared by focused ion beam.[Results]The TEM images show that dislocation loops and bubbles appeared in the irradiated alloy samples.The average sizes and number densities of dislocation loops in the SLM 304L and TM 304L alloy samples are(2.13±0.53)nm and(1.94±0.46)nm,1.48×10^(22) m^(-3) and 6.94×10^(22) m^(-3),respectively.The average sizes and number densities of Xe bubbles in the SLM 304L and TM 304L alloy samples are(3.71±1.40)nm and(1.37±0.46)nm,3.50×10^(22) m^(-3) and 1.73×10^(23) m^(-3),respectively.The both alloy samples show the irradiation hardening after Xe ion irradiation.The irradiation hardening degrees of the SLM 304L and TM 304L alloy samples are 14%and 32%,respectively.[Conclusions]The calculation results based on the dispersed barrier hardening model(DBH)reveal that the dislocation loops and Xe bubbles caused by irradiation play an important role in irradiation hardening of the two kinds of alloys.

关 键 词：SLM 304L不锈钢 Xe离子辐照 微观结构 辐照硬化 

分 类 号：TL341[核科学技术—核技术及应用]