Ni-Cr-Al-Fe基铸态合金的高温氧化行为  

High-temperature oxidation behavior of as-cast Ni-Cr-Al-Fe based alloys

作　　者：韩朝[1] 刘咏[1] 王岩[1] 李维杰[1] 汤慧萍 

机构地区：[1]中南大学粉末冶金研究院粉末冶金国家重点实验室,长沙410083 [2]西北有色金属研究所多孔材料国家重点实验室,西安710016

出　　处：《粉末冶金材料科学与工程》2011年第6期806-814,共9页Materials Science and Engineering of Powder Metallurgy

基　　金：国家高技术研究发展计划(863计划)资助项目(2009AA032601)

摘　　要：采用熔铸法制备不同Al含量的Ni-Cr-Al-Fe基合金,研究Al含量和预氧化处理对合金在600℃大气中抗氧化性能的影响,并利用FE-SEM(EDS)、XRD对不同状态合金氧化膜的形貌及成分进行对比分析。结果表明:Ni-Cr-Al-Fe基合金在600℃时的氧化动力学曲线较好地遵循抛物线规律,铝含量的增加以及预氧化处理均可提高合金的高温抗氧化性能;Ni-Cr-Al-Fe基合金在1 000℃预氧化以及600℃氧化时所形成的氧化膜成分与Al含量有关,Al含量越高越有利于单一Al2O3氧化膜的形成,对提高合金的抗氧化性能有益;随着氧化时间的延长,表面局部区域可进一步形成尖晶石类氧化物或复杂氧化物;预氧化处理所形成的氧化膜,可有效地防止Ni-Cr-Al-Fe基合金基体的氧化;同时,利用WAGNER的临界理论计算了600℃下的Ni-Cr-Al稳定氧化物图。Ni-Cr-Al-Fe based alloys with different Al content were prepared by fusion casting. The effects of Al content and pre-oxidation treatment on oxidation behavior of the Ni-Cr-Al-Fe based alloy were investigated. The morphology and chemical composition of the oxide films were characterized by FE-SEM （EDS） and XRD, respectively. The results show that the oxidized kinetic curves of the Ni-Cr-Al-Fe based alloys at 600℃follow the parabolic rule. Both of the increase of Al content and pre-oxidation treatment can enhance the oxidation resistance of the alloy. The compositions of the oxide films after pre-oxidation at 1 000℃ and oxidation at 600℃ are closely related to the AI content. Higher Al content is helpful to the formation of single Al2O3 structure, which is beneficial to the oxidation resistance of the alloy. With further oxidation, complex oxide or spinel-type oxide may be formed at the local region of the surface. The oxidation of the matrix of the Ni-Cr-Al-Fe based alloy can be effectively prevented after the pre-oxidation treatment. Stable oxide phase diagram of ternary Ni-Cr-Al alloys at 600℃ is also calculated by Wagner＇s critical theoretics.

关 键 词：Ni-Cr-Al-Fe基合金 高温氧化 铝含量 预氧化 氧化机理 

分 类 号：TG136.1[一般工业技术—材料科学与工程]