MAX相Ti3SiC2管材在高温高压水和过热蒸汽中的腐蚀行为

Corrosion Behavior of Max Phase Ti3SiC2 Tube in High-Temperature High-Pressure Water and Superheated Steam

摘要:

MAX相材料有作为事故容错燃料(Accident Tolerant Fuel,ATF)包壳材料的潜力,为了全面了解MAX相材料在模拟正常工况下的腐蚀行为,本工作使用基体为Ti3SiC2的MAX相陶瓷管材于400 ℃/10.3 MPa过热蒸汽,360 ℃/18.6 MPa去离子水、3.5 ppm Li+1000 ppm B溶液和70 ppm Li溶液4种不同的水化学条件中进行腐蚀试验,采用XRD、SEM和FIB/TEM观察分析腐蚀前后样品的显微组织、晶体结构和成分。结果表明,Ti3SiC2管材在4种条件下的腐蚀速率均远高于参比Zr-4合金,腐蚀后主要检测到腐蚀产物TiO2,且其表面疏松多孔,未形成保护性的氧化膜。

Abstract:

MAX phases have the potential to be used as accident tolerant fuel (ATF) cladding materials. In order to fully understand the corrosion behavior of MAX phases under the simulated normal service conditions,the MAX phase ceramic tube with Ti3SiC2 matrix was exposed to 400 ℃/10.3 MPa superheated steam, 360 ℃/18.6 MPa deionized water, 3.5 ppm Li + 1000 ppm B solution and 70 ppm Li solution for corrosion tests. The microstructure, crystal structure and composition of the samples before and after corrosion were observed by XRD, SEM and FIB/TEM. The results show that the corrosion rates of Ti3SiC2 under the four corrosion conditions are all much higher than that of reference Zr-4 alloy, TiO2 was characterized as the main corrosion product; loose and no protective oxide film was formed on the surface of Ti3SiC2 tube.