温度和相结构对镧扩散动力学的影响  

Effect of Temperature and Phase Constitution on Kinetics of Lanthanum Diffusion

作　　者：阎牧夫[1] Bell T Sun Y 刘志儒[1] 夏立芳[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001 [2]英国伯明翰大学冶金与材料系

出　　处：《中国稀土学报》2001年第2期186-189,共4页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金! (5 0 0 410 0 3 );欧共体基金! (BPRP CT 97 0 5 46)资助项目

摘　　要：研究了等离子体渗氮过程中La在密排六方ε Fe2～ 3N(ε)和面心立方γ′ Fe4N (γ′)双相中的扩散动力学规律。与γ′相或ε +γ′双相比较 ,发现ε相对La的扩散具有阻碍作用。一定温度下 ,随着渗氮时间的延长 ,ε相不断分解出γ′相 ;La在单相 (如γ′相 )和双相ε +γ′中的扩散深度分别呈抛物线和近似指数规律增加。提高渗氮温度 ,La扩散的深度增加 ,但其扩散动力学规律并未因此而改变 ;温度从 5 2 0℃升高至5The diffusion of La in ε Fe 2～3 N(ε)and γ′ Fe 4N (γ′) phases formed by plasma nitriding was studied. It is found that with increasing nitriding time, the ε phase continuously decomposes into γ′ under employed experimental conditions. Comparing with γ′ phase or ε+γ′ ones, the mono phase ε has an impedient effect on La diffusion. La layer grows in the dual phases and mono phase follows an approximate exponential law and a parabolic one respectively and does not change with increasing temperature. Effect of increasing temperature in the range of 520 ℃ to 560 ℃ on La diffusion is less than that of phase constitution change such as decomposition of ε phase into γ′ one.

关 键 词：稀土 等离子渗氮 相结构 镧 扩散动力学 钢 化学热处理 温度 脉冲等离子体 催渗作用 

分 类 号：TG156.82[金属学及工艺—热处理] TG161[金属学及工艺—金属学]