论文部分内容阅读
研究镍基合金C276在550~650℃/25 MPa超临界水中的腐蚀特性.采用腐蚀增重、扫描电镜、能谱和X射线衍射方法分析材料的氧化动力学、氧化膜形貌、合金元素分布和组织结构.结果表明,C276合金在超临界水中以均匀腐蚀为主,其腐蚀增重服从抛物线生长规律.当温度由550℃升高到600℃时,材料的腐蚀增重大约升高到3倍;当温度进一步升高到650℃时,材料的腐蚀增重反而下降.C276合金表面氧化膜分层不明显,氧化膜的主要成分为(Ni,Fe)Cr2O4,同时其表层离散分布着大量的Ni O氧化物颗粒.C276合金表面氧化膜的保护性能主要取决于氧化膜内Cr含量,Cr含量越高其结构越致密,从而保护性能也越好.
The corrosion behavior of nickel-base alloy C276 in supercritical water at 550 ~ 650 ℃ / 25 MPa was studied.The oxidation kinetics, oxide film morphology and alloying element distribution of the material were analyzed by means of corrosion weight gain, scanning electron microscopy, energy dispersive X-ray diffraction and X-ray diffraction The results show that C276 alloy is mainly composed of uniform corrosion in supercritical water, and its corrosion weight is subject to the parabolic growth law.When the temperature rises from 550 ℃ to 600 ℃, the corrosion weight gain increases to about 3 When the temperature is further increased to 650 ℃, the corrosion resistance of the alloy decreases but the oxide film on the C276 alloy layer is not obviously stratified, the main component of the oxide film is (Ni, Fe) Cr2O4, while the surface layer is dispersed with a large number of Of the Ni O oxide particles.C276 alloy surface oxide film protection mainly depends on the Cr content in the oxide film, the higher the Cr content of its structure is more dense, and thus the better the protection performance.