镍基合金Inconel 617在高温超临界CO_(2)下的腐蚀特性研究

Study on Corrosion Characteristics of Nickel-based Alloy Inconel 617 in High-temperature Supercritical Carbon Dioxide

对镍基合金Inconel 617在550~700℃、15~25 MPa超临界二氧化碳(S-CO_(2))环境下进行了1000 h的氧化腐蚀实验,得到了其氧化动力学曲线,并借助扫描电镜(SEM)、电镜自带能谱仪(EDS)、X射线衍射仪(XRD)和原子力显微镜(AFM)等表征手段对氧化膜的形貌、物相及成分进行了分析。结果表明:温度显著影响合金的氧化速率,700℃时氧化动力学呈立方规律;在所有温度下合金都形成了致密的单层氧化膜结构,随着温度升高,下方晶界处出现少量孔洞;在合金表面氧化膜主要出现富Ti疖状氧化物,下方晶界孔洞处出现了Al氧化物的富集。

The oxide corrosion experiment was carried out on Inconel 617 nickel-based alloy in supercritical carbon dioxide environment at 550-700℃and 15-25 MPa for 1000 h.Then oxidation curves of alloy were obtained.The oxide scale morphology,phase and composition were analyzed by means such as SEM、EDS、XRD and AFM.Results show that the oxidation rate is significantly affected by temperature.Oxidation kinetics exhibits the cubic rule at 700℃.The alloy forms a compact monolayer oxide film structure at all temperatures.With the increase of temperature,a few holes appear at the lower grain boundary.There are mainly Ti-rich nodular oxides on the surface of the alloy and Al oxide enrichment in grain boundary pores below.