奥氏体ODS钢在超临界水中的腐蚀行为

Corrosion Behavior of Austenitic ODS Steel in Supercritical Water

摘要: 研究了奥氏体ODS钢（316-ODS）在600 ℃/25 MPa超临界水（SCW）中的腐蚀特性。采用腐蚀增重法、SEM、EDS和XRD分析了材料的氧化动力学、氧化膜的形貌、合金元素分布和组织结构。研究结果表明，316-ODS钢在SCW中出现了疖状腐蚀，同时还出现了敏化，其腐蚀增重服从幂指数生长规律。316-ODS钢表面氧化膜为双层结构，内层氧化膜富Cr贫Fe，其主要成分为FeCr₂O₄，而外层氧化膜富Fe贫Cr，其主要成分为Fe₃O₄。

Abstract: Corrosion behaviors of austenitic ODS steel （316-ODS） exposed to 600 ℃/25 MPa supercritical water (SCW) were investigated. The oxidation kinetics, oxide morphology, element distribution and structure of oxide scale were characterized by weight gain measurement, SEM, EDS and XRD. The results show that 316-ODS steel exposed to SCW exhibits nodular corrosion, sensitization and exponential kinetics in weight gain. The oxide scale shows duplex structure. The inner oxide layer is Cr-riched and Fe-depleted, which mainly consists of FeCr₂O₄, while the outer oxide layer is Fe-riched and Cr-depleted, which mainly consists of Fe₃O₄.