H_(2)/H_(2)O气氛下Fe‒C合金薄带气固脱碳反应动力学  

Gas-solid reaction kinetics of decarburization of Fe-C alloy strips in H_(2)/H_(2)O

作　　者：艾立群 侯耀斌 洪陆阔 周美洁 孙彩娇 孟凡峻 周玉青 AI Li-qun;HOU Yao-bin;HONG Lu-kuo;ZHOU Mei-jie;SUN Cai-jiao;MENG Fan-jun;ZHOU Yu-qing(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学冶金与能源学院,唐山063210

出　　处：《工程科学学报》2021年第6期816-824,共9页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51374090);河北省自然科学基金资助项目(E2019209160,E2018209284);河北省教育厅科技基础研究资助项目(JQN2019007);河北省研究生创新资助项目(CXZZBS2020131)。

摘　　要：为对H_(2)/H_(2)O气氛下Fe‒C合金薄带的气固反应脱碳进行动力学研究,在保证快速脱碳而铁不氧化的前提下,利用可控气氛高温管式脱碳炉,研究了不同的脱碳温度、薄带厚度、脱碳时间对Fe‒C合金薄带脱碳效果的影响.结果表明延长脱碳时间、提高脱碳温度、减少薄带厚度均可提高脱碳效果.当脱碳温度为1353 K,在脱碳过程中,薄带可以分成明显的3层,由表面到内部依次是完全脱碳层、部分脱碳层和未脱碳层.完全脱碳层的组织为铁素体,此部分碳含量最低;部分脱碳层由铁素体、渗碳体和少量石墨相组成,未脱碳层由珠光体和大量石墨相组成,此部分碳含量最高.脱碳层的厚度随着脱碳时间的延长而增加,脱碳层的厚度y与时间t平方根满足良好的线性关系,可用函数y=kt0.5描述,碳原子扩散所需扩散激活能为122.36 kJ·mol^(−1),脱碳反应为表观一级反应,表观活化能为153.79 kJ·mol^(−1).To address environmental issues and decrease production costs,the disruptively innovative solidstate steelmaking process was investigated.In this process,a high-carbon sheet is continuously decarburized using an oxidizing gas to achieve a lowcarbon sheet.A significant benefit of the process is the elimination of several conventional processes,including the basic oxygen process,secondary refinement processes,and continuous casting,and the absence of inclusions.The most important feature of the process is the use of high-carbon iron melts to avoid inclusion formation,so that secondary refinement processes are eliminated.To study the gas–solid reaction kinetics of the decarburization of Fe–C alloy strips in H_(2)/H_(2)O,the effects of the decarburization temperature,strip thickness,and decarburization time on the decarburization effect of the Fe–C alloy strips were studied by a controlled-atmosphere high-temperature tube decarburization furnace.The results show that prolonging the decarburization time,increasing the decarburization temperature,and reducing the strip thickness can improve the decarburization effect.The Fe–C alloy strip cross section is composed of the complete decarburization layer,partial decarburization layer,and nondecarburized layer at 1353 K.The microstructure of the complete decarburization layer is ferrite.The partial decarburization layer is composed of ferrite,cementite,and a small amount of graphite phase.The nondecarburized layer is composed of pearlite and a large amount of graphite phase.The thickness of the decarburized layer has a good linear relationship with the square root of the decarburization time,which can be described by the function y=kt0.5.The diffusion activation energy of the decarburization reaction of the 1.5 mm Fe–C alloy strip is 122.36 kJ·mol^(−1).The variations of the average carbon content were studied,and the apparent activation energy of the decarburization reaction of the Fe–C alloy strips was 153.79 kJ·mol^(−1).

关 键 词：脱碳 动力学 气固反应 Fe–C合金 扩散 

分 类 号：TF746[冶金工程—钢铁冶金]