LBE腐蚀对316L纤维毡拉伸性能的影响

摘要

基于中国铅基研究堆CLEAR-Ⅰ高温运行环境,研究了过滤材料烧结316L纤维毡在氧浓度1×10-6 wt%、温度500℃、静态铅铋合金(lead bismuth eutectic,LBE)中腐蚀不同时间后拉伸性能的变化规律.结果表明,在腐蚀500 h、1000 h、1500 h后,纤维毡的抗拉强度分别下降至原始纤维毡的67%、33%和15%,其主要原因是在本实验条件下,LBE腐蚀导致烧结结点结合强度的下降和纤维丝丝径的减小.微观结构分析表明,316L纤维丝表面形成一层不断增厚的致密(Fe,Cr)3O4尖晶石氧化膜,该氧化膜形成与生长降低了纤维丝之间结点的结合强度,同时减小了纤维丝的有效丝径,进而导致纤维毡整体抗拉强度的下降.%Based on the operation environment of China Lead-based Research Reactor (CLEAR-I),the tensile properties of filter material-sintered 316L fiber felt exposed to stagnant lead bismuth eutectic (LBE) with 1×10-6 wt% oxygen concentration was investigated at 500℃ for 500 h,1000h,1500 h.The results showed that compared to the original fiber felt,the tensile strength of the fiber felts decreased to 67%,33% and 15% after 500 h,1000 h and 1500 h,respectively.It was found that the binding strength of the joints and diameter of 316L stainless steel fibers gradually decreased with exposure time due to the compact single-layer (Fe,Cr)3O4 spinel formation on 316L fibers,which was the main cause of tensile strength of sintered 316L fiber felt dropping after LBE corrosion.