铼对CoNiCrAlY涂层合金抗热腐蚀性能的影响

Influence of Rhenium on Hot Corrosion Resistance of CoNiCrAlY Coating Alloys

摘要:

对一种掺3%~5%(质量分数, 下同)铼(Re)的CoNiCrAlY燃气轮机用高温涂层合金在1000 ℃进行热腐蚀实验，利用X射线衍射、SEM和EDS分析其热腐蚀行为。结果表明，无论掺杂Re与否，涂层合金均产生内氧化现象；与不掺杂Re的合金相比， CoNiCrAlY合金中Re的加入能够减小贫Al区的厚度，稳定α-Cr(Re)相，有利于Cr2O3氧化膜的形成，进而阻挡了熔融的Na2SO4与基体的接触，防止熔盐对基体的热腐蚀

Abstract:

The effects of 3%-5% rhenium addition (mass fraction, similarly hereinafter) on the high-temperature corrosion resistance of CoNiCrAlY alloys were evaluated at 1000 ℃ by means of XRD, SEM and EDS. It is shown that there is an internal oxidation whether the rhenium is added to the alloy or not. The addition of rhenium can reduce the thickness of Al-depletion zone, stabilize the α-Cr(Re) phase and benefit the formation of Cr2O3 oxide scale which separates the base material from the molten salt and prevents from high-temperature corrosion