水化学因素对800H合金在超临界水冷堆中服役性能研究  

Effect of Water Chemistry on the Performance of Alloy 800H in Supercritical Water-cooled Reactor

作　　者：苏豪展 黄涛 张乐福[1] 陈凯[1] Su Haozhan;Huang Tao;Zhang Lefu;Chen Kai(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai,200240,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《核动力工程》2023年第5期267-274,共8页Nuclear Power Engineering

基　　金：国家重点研发计划(2018YFE0116200)。

摘　　要：为研究超临界水环境下温度、溶解氧等水化学因素对于堆内包壳材料服役性能的影响规律,探究超临界水冷堆的水化学控制策略,以800H合金作为实验材料,测量了不同温度、水化学条件下超临界水中材料的腐蚀增重规律和慢应变速率拉伸曲线。温度的提升将加快800H合金的腐蚀速率,腐蚀激活能约为159 kJ/mol;温度由550℃升高至650℃,材料的屈服强度变化不显著,约为175 MPa,但屈强比显著下降,呈现明显的软化趋势;650℃下溶解氧浓度由0μg·kg^(-1)提升至500μg·kg^(-1),导致腐蚀增重量增加约30%,而使用联氨除氧的水化学控制方法可以降低800H合金的腐蚀速率;溶解氧浓度对于慢应变速率拉伸的测试结果并无明显作用,这主要是由于超临界水环境下材料的应力腐蚀失效由蠕变过程主导。研究结果表明超临界水环境下进行温度和溶氧控制有助于降低800H合金的腐蚀速率并保持其力学性能。In order to study the influence of water chemistry factors such as temperature and dissolved oxygen on the service performance of cladding materials in supercritical water environment,and to find out the water chemistry control policy of supercritical water-cooled reactor,Alloy 800H was used as the experimental material in this paper,and the corrosion weight gain and slow strain rate tensile curve of the material in supercritical water under different temperature and water chemistry conditions were measured.Increasing the temperature would accelerate the corrosion rate of Alloy 800H,and the corrosion activation energy was about 159kJ/mol.Increasing the temperature from 550℃ to 650℃,the yield strength of the material did not change significantly,which was about 175 MPa.However,the ratio of yield strength over tensile strength decreased significantly,showing an obvious softness trend of the material.At 650℃,raising the dissolved oxygen concentration from 0 μg·kg~(-1) to 500 μg·kg~(-1) resulted in an increase of corrosion weight gain of about 30%,but the water chemistry control method using hydrazine deoxygenation could reduce the corrosion rate of Alloy 800H.The dissolved oxygen concentration did not have a significant effect on the results of slow strain rate tensile testing,mainly because the stress corrosion failure of the material in supercritical water environment is dominated by creep process.The results indicate that appropriate controlling of temperature and dissolved oxygen in supercritical water environment can be helpful to reduce the corrosion rate of Alloy 800H and maintain its mechanical properties.

关 键 词：超临界水冷堆 800H合金 水化学 应力腐蚀 

分 类 号：TL341[核科学技术—核技术及应用]