摘要
文摘利用扫描电镜、X射线衍射分析、能谱分析等手段,从合金成分、热处理组织形貌、界面分布等方面研究了Ni-20Cr-18W基高温合金在900℃温度下25%Na Cl+75%Na2SO4混合熔融盐中的热腐蚀行为。结果表明:Ni-20Cr-18W基高温合金的腐蚀行为是酸碱熔融机理。腐蚀层呈平面向合金基体推进,无明显择优腐蚀现象发生,主要腐蚀产物为疏松多孔的Ni O和Ni3S2腐蚀产物,导致合金表面失去保护性氧化层,增加了腐蚀速度。合金抗热腐蚀性能的降低是因高含量W元素在SO42-作用下腐蚀加剧及第二相粒子与基体的相间腐蚀导致。
In this work, hot corrosion behavior of Ni-20Cr-18W based superalloys at 900℃ has been investiga- ted. The alloy corroded in 75 % Na2 SO4 ＋25 % NaCl mixture molten salt has been analyzed by optical microscope, X -ray diffraction, scanning electronic microscope and energy sispersive X-ray analysis. Results show that the Ni-20Cr -18W based superalloy represents basic dissolution model. The corrosion front goes ahead as a plane into the matrix of alloy without selective corrosion behavior. Most of outcomes in the outer corrosion layer are NiO and Ni3 S2. The al- loy surface loses protective oxide layer and the outcomes increase the corrosion rate. The high thermal corrosion rate of alloy can be ascribed to the tungsten element and the corrosion between second phase particles and matrix.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2014年第6期26-29,共4页
Aerospace Materials & Technology
基金
国家自然科学基金(51171150)
