大型转炉IF钢终点氧含量控制实践

Practice of Controlling the End-point Oxygen Content of IF Steel in Converter

氧化物夹杂是IF钢轧制过程中产生翘皮和带状缺陷的主要因素,为了减少钢中氧化物夹杂,必须降低转炉终点氧含量。邯宝炼钢厂转炉采用IF钢高拉碳、扩大出钢口直径、降低出钢温度等措施,实现了终点低氧出钢。实践表明:采取高拉碳后转炉终点w(C)由平均0.033%提高至0.041%;出钢口扩径后出钢时间由6.5 min缩短至5.2 min;出钢温度由1 674.6℃降低至1 658.3℃,终点w(O)由0.057 85%降低至0.043 15%;碳氧积由0.001 88降低至0.001 74;提高了IF钢的质量。

Oxide inclusion is the primary cause of surface upward and strip defects in the IF rolling process.To minimize oxide inclusions in steel,it is essential to lower the oxygen content at the converter end-point.The converter in Hanbao Steelmaking Plant adopts IF steel with high catch carbon and enlarged tapping hole diameter to reduce tapping temperature and realize low oxygen content tapping.The practice shows that the end carbon content of converter is increased from 0.033% to 0.041% on average after adopting high catch carbon.The tapping time is shortened from 6.5 min to 5.2 min after the tapping hole is enlarged.The tapping temperature decreased from 1 674.6 ℃ to1 658.3℃,and the end-point oxygen content decreased from 578.5 ppm to 431.5 ppm,Carbon and oxygen product decreased from0.001 88 to 0.001 74.The quality of IF steel is improved.