摘要
采用涂Na Cl/Na2SO4盐方法研究了DZ466合金在850℃和950℃条件下热腐蚀行为.结果表明:合金的腐蚀层包括三个区域,最外层为(Ni,Co)O氧化物层,次外层为尖晶石结构氧化层(Ni,Co)Cr2O4,内层为内腐蚀层,850℃时该层为Ni3S2,而950℃时除Ni3S2外,在靠近次外层还形成内氧化Al2O3;在850℃和950℃时合金的热腐蚀机制相同,氧化膜连续性的破坏,是合金遭受热腐蚀的主要原因;热腐蚀增重曲线均符合抛物线规律,其速率常数分别为3.1×10-11g2·cm-4·s-1和1.5×10-9g2·cm-4·s-1,热腐蚀激活能分别为179.2 k J·mol-1和138.3 k J·mol-1.
Hot corrosion behaviors of DZ466 alloy at 850 ℃ and 950 ℃ were investigated by using a NaC l / Na2SO4salt-deposit method. It is found that there are three corrosion layers on the alloy. The outer and the middle layers consist of（ Ni,Co） O oxide and（ Ni,Co） Cr2O4 with a spinel structure,respectively. The innermost layer is an inner corrosion layer,which consists of Ni3S2 at 850℃,and the internal oxidation Al2O3 can be produced close to the middle layer at 950 ℃. The same hot corrosion mechanism is shown at 850 ℃ and 950 ℃. The destruction of the oxidation film continuity is a key reason for hot corrosion of the alloy. The hot corrosion weight gain curves obey a parabolic law at the two temperatures,the rate constants are 3. 1 × 10^-11g^2·cm^-4·s^-1and 1. 5 × 10^-9g^2·cm^-4·s^-1,and the hot corrosion activation energies are 179. 2 and 138. 3 kJ ·mol^-1at 850 ℃ and 950 ℃,respectively.
出处
《工程科学学报》
EI
CAS
CSCD
北大核心
2015年第5期608-614,共7页
Chinese Journal of Engineering
基金
国家高技术研究发展计划资助项目(2012AA03A511)
中央高校基本科研业务费资助项目(FRF-TP-14-062A2)
高等学校学科创新引智计划资助项目(B12012)
关键词
高温合金
定向凝固
涂盐
热腐蚀
腐蚀膜
superalloys directional solidification salt deposits hot corrosion corrosion films
