ABSTRACT

Corrosion was currently the most crucial factor hindering the commercial development of supercritical water oxidation (SCWO) technology. Stainless steel represented by 316L and Ni-based alloy represented by Inconel 625 were performed and compared with corrosion resistance in supercritical environment with high concentrations of oxygen and chlorides. The results shown that the duplex layer was formed on two samples. The surface of 316L SS was mainly composed of loose magnetite and haematite, resulted in pitting corrosion, microcracks, and the exfoliation of oxide. The inner layer were separately a small amount of Cr₂O₃ oxide and FeCr₂O₄ spinel, which were caused by the lower content of chromium. Compared with 316L SS, the oxide film structure of Inconel 625 was composed of the outer layer of spinel and the inner layer of Cr-rich oxide. Some nodular oxides were formed, and it can be explained by the volatilisation process of chromium.

摘要

腐蚀是目前阻碍超临界水氧化（SCWO）技术商业发展的最关键因素。对以316L为代表的不锈钢和以Inconel 625为代表的镍基合金进行了研究，并与高浓度氧和氯化物的超临界环境中的耐腐蚀性能进行了比较。结果表明，在两个样品上形成了双相层。316L SS表面主要由松散的磁铁矿和赤铁矿组成，导致点蚀、微裂纹和氧化物剥落。内层分别为少量Cr ₂ O ₃氧化物和FeCr ₂ O ₄尖晶石，这是由于铬含量较低所致。与316L SS相比，Inconel 625的氧化膜结构由外层尖晶石和内层富铬氧化物组成。形成了一些球状氧化物，这可以用铬的挥发过程来解释。