摘要
超临界二氧化碳(supercritical carbon dioxide,S-CO )能够显著提升循环发电效率而受到学术界的广泛关注,然而高温材料的耐腐蚀性能是限制机组效率的主要因素,要求耐热钢能够满足发电设备的安全运行需求。该文选取3种耐高温材料(铁素体耐热钢T91、奥氏体不锈钢304和镍基高温合金617),探究3种耐热材料在600℃、15 MPa的研究级和工业级S-CO_(2)环境下500 h的腐蚀行为。利用腐蚀动力学增重曲线、电子显微镜(scanning electron microscope,SEM)、分析能谱(energy dispersive spectrometer,EDS)、X射线衍射仪(X-Ray diffraction,XRD)和Raman图谱对腐蚀产物进行表征。结果表明:T91和304在工业级S-CO_(2)下的腐蚀增重量均大于研究级S-CO_(2);T91的双层氧化膜由外层Fe_(3)O_(4)和内层(Fe,Cr)_(3)O_(4)组成,在工业级S-CO_(2)腐蚀下氧化膜中出现Fe_(2)O_(3);304和617氧化膜是单层Cr_(2)O_(3)氧化物,能较好地阻止杂质气体的腐蚀和渗碳反应的发生,因此研究级与工业级S-CO_(2)下腐蚀差异较小。结果可为S-CO_(2)机组的选材和预防腐蚀提供一定参考。
Supercritical carbon dioxide(S-CO_(2))has gained widespread attention in academia due to its unique critical pressure and temperature.The corrosion resistance of high-temperature materials remains a primary limiting factor affecting the efficiency of power generation units,necessitating that heat-resistant steels meet the safety requirements of power generation equipment.This paper selects three types of high-temperature materials:ferritic heat-resistant steel T91,austenitic stainless steel 304,and nickel-based superalloy 617,and investigates their corrosion behavior after 500 hours in a research-grade and industrial-grade S-CO_(2) environment at 600℃ and 15 MPa.The corrosion products are characterized using corrosion kinetic weight gain curves,scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD),and Raman spectroscopy.The results indicate that the weight gain due to corrosion for T91 and 304 in an industrial-grade S-CO_(2) environment is higher than that in a research-grade S-CO_(2) environment.The dual-layer oxide film of T91 consists of an outer layer of Fe_(3)O_(4) and an inner layer of(Fe,Cr)_(3)O_(4).In industrial-grade S-CO_(2) corrosion,Fe_(2)O_(3) appears in the oxide film.The oxide films of 304 and 617 consist of a single layer of Cr_(2)O_(3) oxide,effectively preventing corrosion by impurity gases and carburization reactions.Consequently,the difference in corrosion behavior between research-grade and industrial-grade S-CO_(2) is minimal for 304 and 617.The findings of this study offer valuable insights for material selection and subsequent corrosion prevention in S-CO_(2) power generation systems.
作者
何闯
梁志远
郭亭山
邵怀爽
赵钦新
HE Chuang;LIANG Zhiyuan;GUO Tingshan;SHAO Huaishuang;ZHAO Qinxin(Key Laboratory of Thermo-Fluid Science and Engineering of MOE(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China)
出处
《中国电机工程学报》
北大核心
2025年第14期5358-5368,I0002,共12页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
国家自然科学基金项目(52276015)。
关键词
超临界二氧化碳
铁素体耐热钢
奥氏体不锈钢
镍基高温合金
supercritical carbon dioxide
ferritic heat-resistant steel
austenitic heat-resistant steel
nickel-based high-temperature alloy
high-temperature corrosion
carburization behavior
