利用箱式电阻炉、SEM 等手段,研究了一种定向凝固Co基合金在不同介质中的热腐蚀行为及机理。研究结果表明:合金在Na2SO4 中的热腐蚀最为严重,在75%Na2SO4+25%NaCl中的热腐蚀程度最轻。合金在Na2SO4 中的热腐蚀过程中主要发生了酸性熔融反应,形成了Al2(SO4)3 ,Cr2Ni3,Cr4Ni15W 和Al4CrNi15等腐蚀产物,而在NaCl中的热腐蚀主要发生了活性氧化反应,合金在75%Na2SO4+25%NaCl中热腐蚀时,部分酸性熔融反应和活性氧化反应受到抑制,主要形成了一系列的Ni-S化合物。

The hot corrosion behavior of a directionally solidified Co-base superalloy in different mediums were investigated by using resistance furnace and SEM methods. As showed by the testing results, the most severity corrosion occurred in Na2SO4, and the least in 75%Na2SO4+25%NaCl when the alloy was corroded at 700℃ for 10 hours.Analysis of SEM and XRD showed that Al2(SO4)3,Cr2Ni3,Cr4Ni15W and Al4CrNi15 formed which indicate acid melting and fusing reaction occured when the alloy corroded in Na2SO4, oxides and chlorides indicate that active oxidation reaction when corroded in NaCl.For corroding in 75%Na2SO4+25%NaCl, some Ni-S compounds formed and the reactions mentioned above were restrained.