【摘要】 本文研究了NiAl-30 at%Fe合金的高温氧化和热腐行为.氧化温度为850,950,1050和1150℃,时间达100h.热腐蚀温度为850℃和950℃,时间分别达25h和22h,样品表面涂75wt-%NaSO₄和25wt-%NaCl混合盐层.结果表明,NiAl-30Fe合金在不同温度下,氧化和热腐蚀动力学曲线皆遵从抛物线规律.在NiAl金属间化合物中降低Al含量加入30 at%Fe明显降低了NiAl化合物的抗氧化和抗热腐蚀能力.采用X射线衍射,金相、扫描电镜和电子探针分析研究了氧化和热腐蚀产物的微观组织结构及成份,并对腐蚀机制进行了初步分析。更多还原

【Abstract】 The isothermal oxidation behaviour of NiAl-30Fe alloy at 850 to 1150℃ for periods up to 100h has been investigated.The hot corrosion performance of the alloy under a 75wt% Na₂SO₄+25wt% NaCl salt film on its surface at 850 to 950℃ for periods up to 22 or 25h has also been studied.The results show that both isothermal oxidation and hot corrosion kinetics of the NiAl-30Fe alloy obey the parabolic law at all test temperatures. The addition of 30at% Fe to NiAl intermetaUic compound resulted in a harmful effect on its corrosion resistance.The microstructure and composition of the oxide layer and hot corrosion product scale have been investigated by means of X-ray diffractometer,optical and scanning electron microscope and EPMA equipped with an EDAX unit.The corrosion mechanism is also discussed on the basis of experimental results.更多还原