某2650m^(3)高炉炉底陶瓷垫刚玉莫来石砖蚀损机理探析

Analysis on Erosion Mechanism of Corundum Mullite Bricks in Ceramic Cup at a 2650 m3 BF Bottom

某2650m^(3)高炉生产运行14年8个月之后,因炉缸侧壁局部热流强度及热电偶温度异常,进行了保护性拆除,炉缸炉底交界处呈明显的“象脚状”侵蚀。对炉底陶瓷垫刚玉莫来石残砖进行微观结构分析,初步探讨了炉底陶瓷垫的蚀损机理。结果表明,在长期高温、高压条件下,铁水对炉底陶瓷垫刚玉莫来石砖的熔蚀及渗透,以及渗透的铁水因温度波动产生体积变化,造成了刚玉莫来石砖出现裂纹或缺陷增大,从而产生结构剥落,最终被铁水冲刷进入渣铁熔体而蚀损。

The erosion mechanism of corundum mullite brick in ceramic cup of a 2650m^(3) BF bottom is analyzed.After operating for 14 years and 8 months,the furnace hearth undergoes protectively disassembly due to the abnormal specific heat flow rate,and abnormal hearth side wall temperature read by the thermocouples.It is found that the furnace bottom and hearth suffer obvious"elephant foot-like"erosion.A microstructure analysis of the residual bricks is carried out,which reveals the erosion mechanism of the corundum mullite bricks in the ceramic cup at the furnace bottom:after long-time furnace operation under high temperature and high pressure,the corundum mullite bricks in the ceramic cup of the furnace bottom are eroded by hot metal erodes,and hot metal penetrates into bricks;the volume of the penetrated hot metal changes along with fluctuation of the hot metal temperature,which enlarges the cracks or defects of the corundum mullite bricks,resulting in structural peel-off.The bricks are scoured by hot metal,and later-on even run into slag and hot metal melt,finally being eroded.