微波场与常规场高碳铬铁粉固相脱碳显微结构对比  

Comparative research on microstructure of high-carbon ferrochrome powders decarburized in solid-state by microwave field and conventional field

作　　者：王超[1] 陈津[1] 林万明[1] 孙宏飞[1] 王龙[1] 

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《中南大学学报（自然科学版）》2015年第3期765-773,共9页Journal of Central South University:Science and Technology

基　　金：钢铁联合研究基金-国家自然科学基金委员会与上海宝山钢铁集团公司联合资助(51174252)~~

摘　　要：研究不同加热场对物料显微结构的影响,为微波加热场的特殊效应提供佐证。以内配碳酸钙高碳铬铁粉为研究对象,采用微波加热和常规加热进行固相脱碳,并对高碳铬铁粉显微结构进行对比研究。实验结果表明:微波加热内配碳酸钙高碳铬铁粉到900℃时,(Cr,Fe)7C3开始分解,在晶粒边缘形成少量的(Cr,Fe)23C6-(Cr Fe);而常规加热内配碳酸钙高碳铬铁粉到900℃时,其金相组织结构没有发生明显的变化;当脱碳温度提高到1 000℃和1 100℃时,微波场高碳铬铁粉中的(Cr,Fe)7C3逐渐消失,(Cr,Fe)23C6-(Cr Fe)大量出现,且分布均匀;而常规加热下(Cr,Fe)23C6-(Cr Fe)含量较少且偏析严重,当脱碳温度达到1 200℃时,微波场中(Cr,Fe)7C3几乎完全分解转变为(Cr,Fe)23C6-(Cr Fe),而常规加热下仍有较多(Cr,Fe)7C3残留,分布极不均匀,氧化程度也明显高于微波加热。微波加热下固相脱碳反应要求的温度低,反应速度快,反应较均匀,氧化程度低,体现出微波加热的优越性,证明微波场对高碳铬铁粉中碳的扩散能力具有明显的增强作用。The effect of different heating fields on microstructure of the material was studied, which provided evidence for special effects of microwave heating field. The high-carbon ferrochrome powders （HCFP） with addition of calcium carbonate powders （CCP） was studied, and the microstructure of HCFP was also comparatively researched after being heated by microwave and conventional field. The results show that （Cr, Fe）7C3 in HCFP begins to decompose, and a small quantity of （Cr, Fe）23C6-（CrFe） forms on the edge of crystalline grain, when mixed material is heated to 900 ℃ by microwave heating. When heated by conventional field, the metallographic structure of HCFP has no obvious change; when the temperature raises to 1 000 ℃ and 1 100 ℃, by microwave heating field, （Cr, Fe）7C3 in HCFP disappears gradually. Meanwhile, a large amount of （Cr, Fe）23C6-（CrFe） forms and uniformly distributes in the matrix. But heated by conventional field, the content of （Cr, Fe）23C6-（CrFe） is low and with serious macro segregation. When heated to 1 200 ℃ by microwave heating, （Cr, Fe）7C3 almost completely turns into （Cr, Fe）23C6-（CrFe）. While being conventionally heated to 1 200 ℃, a lot of （Cr, Fe）7C3 remain with very unevenly distribution, and the degree of oxidation is obviously higher thanthat of microwave heating. The solid state decarburization by microwave heating has the characteristics as follows： low temperature, fast and uniform reaction rate, low oxidation degree, which embody the superiority of microwave, and it can significantly improve the diffusivity of the carbon in HCFP.

关 键 词：微波加热 常规加热 高碳铬铁粉 固相脱碳 显微结构 碳扩散 

分 类 号：TF641[冶金工程—钢铁冶金]