The iso-thermal oxidation of the quaternary Co-20Re-25Cr-3Si alloy at 1000-1200 ℃ under laboratory air for 24 h has been studied. The kinetics at 1000-1200 ℃ conform quite well to parabolic law during the whole oxidation process with the value of oxidation activation energy equal to 220.74 kJ/mol. Unlike the case of the experimental condition of 0.1 MPa pure oxygen, a dense and continuous layer of Cr2O3 in contact with the alloy has formed on Co-20Re-25Cr-3Si alloy at 1000-1200 ℃ under laboratory air, accounting for the good oxidation resistance of the alloy. A 79% drop in oxygen pressure has changed the oxidation mode from catastrophic oxidation to mild oxidation. The thickness of the protective Cr2O3 layer decreases when temperature increases. Therefore, Co-20Re-25Cr-3Si alloy shows the best oxidation resistance at 1000 ℃. Moreover, from another perspective, compared with Co-17Re-23Cr-3Si alloy, the addition of about 2% Cr can also improve the oxidation resistance of the alloy greatly by forming the protective Cr2O3 layer.

中文翻译：

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四元Co-20Re-25Cr-3Si合金在实验室空气中的氧化行为

研究了四元Co-20Re-25Cr-3Si合金在1000-1200℃、实验室空气中24h等温氧化。在整个氧化过程中，1000-1200℃的动力学符合抛物线规律，氧化活化能为220.74 kJ/mol。与0.1 MPa纯氧实验条件的情况不同，在实验室空气中1000-1200 ℃下，Co-20Re-25Cr-3Si合金与合金接触形成致密连续的Cr2O3层，说明氧化性良好合金的电阻。氧气压力下降 79% 已将氧化模式从灾难性氧化转变为轻度氧化。当温度升高时，Cr2O3 保护层的厚度减小。因此，Co-20Re-25Cr-3Si合金在1000℃时表现出最好的抗氧化性。而且，