强γ辐照下Q235碳钢在甘肃北山地区地下水模拟液中的腐蚀行为  

Corrosion Behavior of Q235 Carbon Steel in Simulated Groundwater in Gansu Beishan Area with High-strength γ Irradiation

作　　者：魏强林[1,2] 刘义保 杨波[1] 刘媛媛[1] 李玉红[2] 黄彦良[3] WEI Qianglin;LIU Yibao;YANG Bo;LIU Yuanyuan;LI Yuhong;HUANG Yanliang(Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, East China University of Technology, Nanchang 330013, China;School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China;Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China)

机构地区：[1]东华理工大学放射性地质与勘探技术国防重点学科实验室,江西南昌330013 [2]兰州大学核科学与技术学院,甘肃兰州730000 [3]中国科学院海洋研究所,山东青岛266071

出　　处：《原子能科学技术》2019年第1期59-66,共8页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(51471160;11505027);江西省教育厅科学技术研究项目资助(GJJ170485);东华理工大学放射性地质与勘探技术国防重点学科实验室开放基金资助项目(RGET1406)

摘　　要：利用1.11×10^(16) Bq(30万Ci)高强度^(60)Co源γ辐照装置,对甘肃北山地区地下水模拟液中高放废物处置罐候选材料Q235碳钢进行了辐照腐蚀试验。采用水化学参数分析、称重、扫描电镜(SEM)、X射线能谱(EDS)和红外光谱(FT-IR)等技术手段,分析了辐照剂量(时间)对辐照腐蚀演化的影响规律,并与未辐照试验进行了对比。结果表明,在长时间强γ辐照下,模拟液辐照分解导致氧化性增强、pH值由弱碱性变为酸性、电导率下降明显,而未辐照的模拟液pH值和电导率未见明显变化;利用质量变化率计算得到的辐照腐蚀速率约为未辐照腐蚀速率的5.5倍,辐照明显加速了Q235碳钢的腐蚀。SEM-EDS和FT-IR分析表明,随着辐照剂量的增加,腐蚀层中出现泡状或针状产物,表面由致密变为稀疏;腐蚀层化学组成以Fe、O为主,含有不同相的羟基氧化铁(α-FeOOH和γ-FeOOH)和氧化铁(α-Fe_2O_3)。Q235 carbon steel is a candidate material of the high level waste (HLW) disposal container. The irradiation corrosion test of Q235 carbon steel was carried out with the high-strength ^60Co radioactive device (1.11×10^16 Bq) in the simulated groundwater in Gansu Beishan aera. Water chemical parameter analysis, weighing, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the effects of irradiation dose (time) on the evolution of irradiation corrosion. The results show that the oxidizability of the simulated groundwater is enhanced, the pH value changes from 7.81 to 4.75, which means that the solution changes from weakly alkaline to strongly acidic under the long-term high-strength γ irradiation. Besides, the electrical conductivity decreases obviously, but there is no significant change for the pH value and electrical conductivity of the non-irradiated solution, and the irradiation corrosion rate calculated by mass change rate is about 5.5 times that of non-irradiation. SEM-EDS and FT-IR analysis shows that bubbles or needles appeare in the corrosion layer. The corrosion layer surface changes from dense to sparse as the radiation dose increases. The chemical composition of the corrosion layer is mainly Fe and O, and the corrosion layer contains different phases of iron oxyhydroxide (α-FeOOH and γ-FeOOH) and iron oxide (α-Fe2O3).

关 键 词：高放废物 处置罐材料 钴源 γ辐照腐蚀 Q235碳钢 

分 类 号：TL933[核科学技术—辐射防护及环境保护] TG174.3[金属学及工艺—金属表面处理]