铸造镍基合金K444在900℃空气中的长期氧化行为  

OXIDATION BEHAVIOR OF Ni-BASED SUPERALLOY K444 AT 900℃IN AIR DURING LONG TERM

作　　者：郭永安[1] 李柏松[2] 赖万慧[1] 郭建亭[1] 周兰章[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]沈阳工业大学材料科学与工程学院,沈阳110059

出　　处：《中国腐蚀与防护学报》2012年第4期285-290,共6页Journal of Chinese Society For Corrosion and Protection

摘　　要：用热重法研究镍基高温合金K444在900℃下氧化1000 h的动力学。结果表明,K444合金氧化动力学遵从抛物线规律,以x射线衍射、扫描电镜和能谱分析及电子探针成分分析测定氧化膜的组成,结果表明氧化膜由多层组成,外层为TiO_2,内层以Cr_2O_3为主还包括内氧化层和贫Υ′层。观察到沿晶界偏聚的碳化物氧化,提出了氧化饥制。The oxidation kinetic of a Ni-based superalloy K444 at 900 ℃ in air was studied by thermo gravity （TG） method. The results show that oxidation kinetic of the K444 obeys the parabolic law. The oxide rate constant of the initial stage is greater than steady-state stage, and the turning point is 25 hours. The composition of oxide layer were examined by X-ray diffraction, scanning electron microscopy, energy spectrum analysis and electron probe micro-analyzer. The oxide scale contains several layers： the outer layer of TiO2 mainly; the intermediate layer of Cr2O3 and internal oxidation layer. The growth of oxide scale is controlled by diffusion. The grain boundary segregation and the oxidation of carbide were also observed.

关 键 词：镍基高温合金 高温氧化 内氧化 碳化物选择氧化 氧化机制 

分 类 号：TG142.7[一般工业技术—材料科学与工程]