Nickel base superalloys (Alloy 600, 690 and 693) under as-received and heat treated (solution-annealed and sensitized) condition have been assessed by electrochemical impedance spectroscopic technique for their corrosion behavior in 3 M HNO₃ and simulated high level waste medium at 25°C. All the alloys in all the conditions (as-received, solution-annealed and sensitized) show higher polarization resistance in 3 M HNO₃ compared to simulated high level waste. The solution-annealed specimens for Alloy 690 and Alloy 693 show near capacitive behaviour in a larger ranger of frequency. Among the three alloys, Alloy 690 show highest polarization resistance followed by Alloy 693 and Alloy 600, due to the better stability of passive oxide layer. In contrast, the decreased polarization resistance for Alloy 600 specimens imply deterioration or reduction in the passive film stability.

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电化学阻抗谱研究模拟高放废液中镍基高温合金的腐蚀

通过电化学阻抗谱技术评估了镍基高温合金（合金600、690和693）在接收和热处理（固溶退火和敏化）条件下在3 M HNO _3中的腐蚀行为，并在模拟高能废介质下进行了测试。 25℃。在所有条件下（如原样，固溶退火和敏化），所有合金在3 M HNO _3中均显示出较高的极化电阻与模拟的高放废物相比 690合金和693合金的固溶退火试样在较大的频率范围内显示出接近电容的行为。在这三种合金中，由于钝化氧化物层的稳定性更好，因此690合金的抗极化强度最高，其次是693和600合金。相反，合金600样品的极化电阻降低意味着无源膜稳定性下降或降低。