摘要
研究了20Cr-25Ni合金和一种新型结构材料含铝的奥氏体耐热钢(AFA钢)在600℃/20 MPa的超临界二氧化碳(S-CO_(2))环境中的腐蚀行为,并对2种合金的氧化膜形貌、成分和结构进行分析。研究发现,20Cr-25Ni合金出现明显的腐蚀增重增长趋势,表现出“抛物线”上升规律;AFA钢腐蚀增重趋势缓慢,腐蚀1000 h后仅为2.11 mg/dm^(2)。20Cr-25Ni合金表面出现粗大的氧化产物,随腐蚀时间延长,AFA钢的氧化膜始终保持致密、连续。通过氧化膜的截面形貌分析发现,20Cr-25Ni合金腐蚀后具有两层氧化膜结构,主要由Fe_(3)O_(4)和FeCr_(2)O_(4)氧化层以及少量尖晶石组成。而AFA钢中出现了3层氧化膜结构,中间和最内层分别为Cr_(2)O_(3)和Al_(2)O_(3)氧化膜,最外层分布了一层不连续的FeCr_(2)O_(4)尖晶石氧化物。由于形成了致密的Al_(2)O_(3)氧化膜,AFA钢的抗腐蚀性能大幅提升。
The corrosion behavior of Alloy 20Cr-25Ni and a new structural material alumina-forming austenitic heat resistant steel(AFA steel)in supercritical carbon dioxide(S-CO_(2))environment at 600℃/20 MPa was studied.The morphology,composition,and structure of oxide films of the two alloys were analyzed.It is found that the weight gain curves of the two alloys were in accord with the“parabola”law.The weight of corrosion products increased slowly;it was only 2.11 mg/dm^(2) after 1000 h.By comparison,the coarse oxide products appeared on the surface of Alloy 20Cr-25Ni and increased with the extension of corrosion time,while oxide film of AFA steel remained dense and continuous.Through the analysis of the cross-sectional morphology of the oxide film,it is found that the Alloy 20Cr-25Ni has a two-layer oxide film structure after corrosion,which is mainly composed of Fe_(3)O_(4) and FeCr_(2)O_(4) oxide layer and a small amount of spinel.However,there are three layers of oxide film structure in AFA steel,the middle and inner layers are Cr_(2)O_(3) and Al_(2)O_(3) oxide films respectively,and the outer layer is distributed with a discontinuous FeCr_(2)O_(4) spinel oxide.Due to the formation of dense Al_(2)O_(3) oxide film,the corrosion resistance of AFA steel is greatly improved.
作者
马赵丹丹
丛硕
陈勇
郭相龙
张瑞谦
刘珠
张弦
Ma Zhaodandan;Cong Shuo;Chen Yong;Guo Xianglong;Zhang Ruiqian;Liu Zhu;Zhang Xian(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;Nuclear Power Institute of China,Chengdu,610213,China;Shanghai Jiao Tong University,Shanghai,200240,China)
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2022年第6期101-107,共7页
Nuclear Power Engineering
