铁氧化层中离子扩散抑制问题研究  

Study on the diffusion control of ion in oxide scale

作　　者：周旬[1] 艾矫健[1] 王晓东[1] 徐海卫[1] 刘朋 魏连启[3] 

机构地区：[1]首钢京唐钢铁联合有限责任公司,河北唐山063000 [2]首钢集团有限公司技术研究院,北京100043 [3]中国科学院过程工程研究所,北京100190

出　　处：《轧钢》2017年第5期12-15,22,共5页Steel Rolling

摘　　要：研究了铁在高温氧化过程中的扩散机理,通过氧化增重试验进行了动力学计算;通过X射线衍射,对晶格参数进行了计算,提出高温下Fe的扩散以及Mg对高温氧化的抑制作用机理。结果表明:Mg^(2+)填充氧化层内层FeO的晶格空位,降低了空位浓度,减小了阳离子穿过FeO层的扩散速率,从而降低了氧化速率。Mg^(2+)取代氧化层外层Fe_3O_4中氧八面体中心的Fe^(2+),生成Mg_xFe_((1-x))O和Mg_xFe_((1-x))Fe_2O_4,通过提高八面体扩散能垒,可以降低阳离子穿过该层的扩散速率。The diffusion mechanism of Fe at high temperature oxidation process was studied.The dynamic parameters were calculated based on the oxidation weight gain test.The lattice parameters were calculated too based on the X-ray experiment.The mechanism of Mg2＋refrain Fe diffusion at high temperature was put forward.The result showed that Mg2＋could occupy the vacancies in wüstite and reduce the concentration of vacancies in wüstite,which lead to the decrease of the velocity of cation diffusion through the oxide scale.As a result,the oxidation rate was reduced.At the same time,Mg2＋could substitute for Fe2＋in inner wüstite and outer spinel layer,and form the relative compact MgxFe（1-x）O solid solution and MgxFe（1-x）Fe2O4 spinel respectively.The substitution would reduce the lattice parameter and enhance the energy barrier of which Fe ions diffusion through the layers.

关 键 词：扩散速率 晶格参数 空位 抑制 

分 类 号：TG335[金属学及工艺—金属压力加工]