Ti(C,N)在炭砖中的原位形成及其对炭砖性能的影响

In-situ formation of Ti( C,N) in carbon blocks and its effect on properties of carbon blocks

为了提升高导热炭砖的抗侵蚀性,以人造石墨(≤0.075、≤1 mm)、Si粉(≤0.045 mm)、Al粉(≤0.075mm)、活性Al2O3(2μm)为原料,酚醛树脂为结合剂,分别外加质量分数6%的TiO2、TiC微粉,经混料、成型,于1 200和1 400℃埋炭热处理后制备了高炉用炭砖试样,研究了TiO2、TiC微粉对试样的物相变化、微孔结构、热导率及抗铁水侵蚀等性能的影响。结果表明:经1 400℃埋炭热处理后,外加6%(w)TiO2试样原位生成了Ti(C,N)和TiN,而引入的TiC较为稳定,在热处理过程中未与其他组分发生反应,且外加6%(w)TiO2试样在SiC晶须的密集区生成了Ti(C,N),与其他试样相比,SiC晶须的量较多,长径比较大;外加6%(w)TiO2试样的平均孔径低于100 nm,小于1μm孔的孔容积率达90%,室温热导率达53.43 W·m-1·K-1;抗铁水侵蚀性试验显示,通过引入TiO2原位形成Ti(C,N)的炭砖试样,其抗铁水熔损性优于直接引入TiC的试样。

In order to improve the corrosion resistance of high thermal conductivity carbon blocks, carbon block specimens containing Ti（C,N） for blast furnace were prepared using artificial graphite （≤0. 075 mm and ≤1 mm）,silicon powder （≤0.045 mm）,aluminum powder （≤0.075 mm）,and reactive alumina （2 μm） as starting materials,phenolic resin as binder,extra adding 6 mass% TiO2 or TiC micropowder,mixing,sha- ping,and hot treating at 1200℃ or 1400 ℃,respectively,in carbon-embedded condition. The effects of TiO2 and TiC additions on phase composition, micropore structure,thermal conductivity, and hot metal corrosion resistance of the specimens were investigated. The results show that TiN and Ti （C, N） phases are in-situ formed in specimens added with 6 mass% TiO2 coked at 1 400 ℃whereas the TiC added in the specimens is stable, does not participate in any reactions ;Ti （C, N） forms in the SiC crystal whisker concentrated area in the specimens containing 6 mass% TiO2;compared with the other specimens,the specimens containing 6 mass% TiO2 has more SiC crystal whiskers with larger rate of length to diameter;the specimen containing 6 mass% TiO2 has a mean pore size less than 100 nm and a volume ratio of pores 〈1 μm reaching 90% ,a cold thermal conductivity of 53.43 W · m^-1· K^-1 ;meanwhile,hot metal corrosion test proves that specimens added with TiO2 to form Ti（C,N） have better corrosion resistance than specimens directly added with TiC powder.