【作者】 张强； 吴世洪； 苗志； 刘鸿；

【Author】 ZHANG Qiang;WU Shi-hong;MIAO Zhi;LIU Hong;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China;

【机构】 中国核动力研究设计院反应堆燃料及材料重点实验室；

【摘要】 SiC涂层在高温环境中具有优异的力学、腐蚀和辐照性能,成为超临界水冷堆的候选包壳材料。本文采用化学气相沉积获得具有不同组织结构特征的片状SiC涂层试样,研究了试样在350℃/10.3 MPa高温水中的腐蚀行为,获得了涂层的腐蚀动力学曲线,认识了晶粒尺寸和晶体类型对其腐蚀行为的影响。研究表明,SiC在高温水中主要发生晶间腐蚀,表现为晶界溶解;影响涂层腐蚀性能的主要因素有晶体类型、晶粒尺寸和致密性,其中致密性尤为重要。β-SiC的腐蚀性能优于α-SiC,致密性越高、晶粒尺寸越大,则涂层的腐蚀性能越好。更多还原

【Abstract】 SiC coating shows excellent mechanical,corrosion and irradiation properties in high temperature environment,and therefore becomes an candidate cladding material for supercritical water cooled reactors.In this research,SiC sheet specimens with various niicrostructure were prepared by Chemical Vapor Deposition(CVD).Corrosion behavior of the SiC coatings were tested in 350 ℃/10.3 MPa water,which gave rise to the corrosion kinetics curve.Effect of grain size and crystal type on the corrosion property has been investigated.It is suggested that the main corrosion mode of SiC in high temperature water is intergranular corrosion,in the form of grain boundary dissolution.The major factors affecting the corrosion property are crystal type,grain size and coating impactness,especially the last one.β-SiC is superior to α-SiC.The higher grain size and coating impactness,the better corrosion resistance.更多还原