蒸气中氧含量对Zr-0.75Sn-0.35Fe-0.15Cr-0.3Nb合金在400℃过热蒸气中耐腐蚀性能的影响  

Effect of Oxygen Content in Steam on the Corrosion Resistance of Zr-0.75Sn-0.35Fe-0.15Cr-0.3Nb Alloy in 400℃Super-Heated Steam

作　　者：裴文 徐诗彤 黄建松 姚美意[1] 林晓冬 张金龙[1] 胡丽娟[1] 彭剑超[2] 梁雪[2] 谢耀平[1] 周邦新[1] Pei Wen;Xu Shitong;Huang Jiansong;Yao Meiyi;Lin Xiaodong;Zhang Jinlong;Hu Lijuan;Peng Jianchao;Liang Xue;Xie Yaoping;Zhou Bangxin(Institute of Materials,Shanghai University,Shanghai 200072,China;Laboratory for Microstructures,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料研究所,上海200072 [2]上海大学微结构重点实验室,上海200444

出　　处：《稀有金属材料与工程》2022年第6期2250-2257,共8页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51871141)。

摘　　要：为探究蒸气中氧含量对Zr-0.75Sn-0.35Fe-0.15Cr-0.3Nb(质量分数,%,下同)合金在400℃过热蒸气中耐腐蚀性能的影响,本研究将合金样品放入静态高压釜和动态高压釜中进行400℃/10.3 MPa除氧和含氧300 ppb的过热蒸气腐蚀试验,采用腐蚀增重曲线表征合金的耐腐蚀性能。利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析了锆合金在2种腐蚀环境下氧化膜的显微组织以及氧化膜/金属(O/M)界面特性。结果表明:蒸气中含氧会加速Zr-0.75Sn-0.35Fe-0.15Cr-0.3Nb合金的腐蚀,在含氧300 ppb条件下腐蚀240 d的增重比除氧条件下高17%;在除氧条件下O/M界面处的过渡层比含氧300 ppb条件下的更薄,过渡层中检测到约为100 nm的ZrO层,而在含氧300 ppb条件下没有检测到ZrO层,更厚的过渡层和ZrO层的存在在一定程度上可以为Zr氧化过程中的应力释放提供更充足的时间,减少裂纹的产生,起到延缓锆合金腐蚀的作用,这与除氧条件腐蚀后期其有较好的耐腐蚀性能相对应。In order to investigate the effect of oxygen content in the super-heated steam on the corrosion resistance of Zr-0.75Sn-0.35Fe-0.15Cr-0.3Nb(wt%)alloy,the samples were put into a static autoclave and a dynamic autoclave for 400℃/10.3MPa/deoxygenation and 300 ppb oxygen super-heated steam corrosion tests.The corrosion resistance of the alloy was evaluated by corrosion mass gain.The microstructure of the oxide film and the characteristics of the oxide f ilm/metal(O/M)interface were analyzed by SEM and TEM.The results reveal that oxygen in the steam can accelerate the corrosion of Zr-0.75Sn-0.35Fe-0.15Cr-0.3Nb alloy,and the mass gain after 250 d exposure under 300 ppb oxygen condition is 17%higher than that under deoxygenation condition.The transition layer at the O/M interface under the deoxygenation condition is thinner than that under the 300 ppb oxygen condition.In addition,a ZrO layer of about 100 nm is observed in the transition layer under the former condition but not observed under the latter condition.To some extent,the thicker transition layer and the existence of the ZrO layer can provide more time for the stress release in the o xidation process,inhibiting the generation of cracks and thus improving the corrosion resistance of zirconium alloys.This can explain the better corrosion property in the later stage of corrosion under the deoxygenation condition.

关 键 词：锆合金 腐蚀 氧含量 显微组织 

分 类 号：TL341[核科学技术—核技术及应用] TG146.414[一般工业技术—材料科学与工程]