【摘要】 对镍基高温合金Inconel 740H和617B在750℃和780℃进行了5000 h的时效及模拟燃煤环境腐蚀试验。使用透射电镜(TEM)、配备能谱(EDS)的扫描电镜(SEM)等对试样表面和截面微观组织进行了分析。结果表明，时效前Inconel 740H合金晶内的γ′相约为5 nm, 750℃和780℃时效后分别为70 nm和95 nm左右。617B合金时效前未观察到γ′相，时效后γ′相析出，并分别长大到100 nm和130 nm左右，说明Inconel 740H合金的组织稳定性比617B合金好。在750℃和780℃模拟燃煤环境的试验证明，Inconel 740H合金比617B合金具有更好的耐腐蚀性，617B合金目前还无法取代Inconel 740H合金。更多还原

【Abstract】 Nickel based superalloys Inconel 740H and 617B were aged at 750 ℃ and 780 ℃ for 5000 h, and then corroded in simulated coal-fired environment. The surface and cross sectional microstructures were characterized by TEM, EDS and SEM. The results show that the size of intragranular γ′ phase in the Inconel 740H alloy is about 5 nm before aging, while after aging at 750 ℃ and 780 ℃ for 5000 h, the average size of γ′ phase is about 70 nm and 95 nm, respectively. The intragranular γ′ phase in the 617B alloy is not observed before aging, while after aging, the γ′ phase is precipitated and grows to about 100 nm and 130 nm, respectively, which shows that the microstructure stability of the Inconel 740H alloy is better than that of the 617B alloy. The corrosion test results in simulating coal-fired environment at 750 ℃ and 780 ℃ show that the Inconel 740H alloy has better corrosion resistance than 617B alloy, so the 617B alloy cannot replace Inconel 740H alloy at present.更多还原