铁素体-马氏体钢K1和K2在超临界水中的腐蚀行为

CORROSION OXIDATION OF FERRITIC-MARTENSITIC STEEL K1,K2 IN SUPERCRITICAL WATER

用扫描电镜(SEM)及能谱(EDS)和X射线衍射(XRD)技术研究国产铁素体-马氏体K1和K2钢在500℃、25 MPa超临界水环境下的腐蚀行为。结果表明,试样表面形成了稳定的氧化膜,氧化膜为双层结构,外层为多孔的磁铁矿,内层为致密的铁、铬复合氧化物。腐蚀动力学结果显示,两种材料的腐蚀行为遵循抛物线规律。K2钢在超临界水中的腐蚀增重较K1钢略高。

The corrosion behavior of two ferritic-martensitic steel K1 and K2 exposed to supercritical water at 500℃ and a pressure of 25 MPa for exposure times of 200 h, 400 h, 600 h, 800 h, 1000 h was investigated. The results from scanning electron microscope/energy dispersive spectroscopy （SEM/EDS） analyses indicated that the oxide scale exhibits typical duplex oxide structure, in which the scale is composed of an outer layer of more porous magnetite, and an inner layer of iron chromium spinel. The results of corrosion dynamic manifest that two materials follow the parabolic rule, and the corrosion oxidation rate of K2 steel is faster than that of K1 steel, but the gap within 5%.