Oxidation and hot corrosion behaviors of Nb-Si based ultrahigh temperature alloys at 900 °C

被引：20

作者：

He, Jia-hua ^{[1
]}

Guo, Xi-ping ^{[1
]}

Qiao, Yan-qiang ^{[1
]}

机构：

[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China

来源：

TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA | 2021年 / 31卷 / 01期

基金：

中国国家自然科学基金; 国家重点研发计划;

关键词：

Nb-Si based alloys; molten salts; oxidation; hot corrosion; silicate; MICROSTRUCTURE; TI; CHLORIDE;

D O I：

10.1016/S1003-6326(20)65488-7

中图分类号：

TF [冶金工业];

学科分类号：

0806 ;

摘要：

Oxidation and hot corrosion behaviors at 900 degrees C of Nb-Si based ultrahigh temperature alloys were investigated. Both oxidation and hot corrosion kinetics curves of the alloy involve an initial parabolic stage and a later rapid linear stage. In the initial oxidation stage (1-50 h), a thin and continuous scale is formed on the alloy surface, while severe pest degradation phenomenon is observed in the linear oxidation stage. Compared with oxidation of the alloy in static air, a linear hot corrosion stage happens earlier and catastrophic scale disintegration occurs after hot corrosion for 20-100 h, demonstrating that molten salts (Na2SO4 and NaCl) could significantly accelerate the oxidation process of the alloy. STEM results indicate that the corroded scale consists mainly of TiO2, Nb2O5, TiNb2O7, amorphous silicate and NaNbO3.

引用

页码：207 / 221

页数：15