Q195连铸板坯中显微夹杂物行为研究

Research on Behavior of Micro-inclusions in Q195 Continuous Casting Slab

系统分析了某厂生产的Q195钢中氧氮含量、钢中显微夹杂物类型、尺寸、数量及分布的变化历程。结果表明:铸坯中夹杂物浓度较高,二次氧化严重;其中显微夹杂物为Al_2O_3-SiO_2-MnO、FeO-Al_2O_3等复合夹杂物,发现Ce、La等示踪元素;说明钢包渣、中间包渣对钢水存在明显污染;含Na、K夹杂物所占比例只有10%,说明结晶器内保护渣对钢水存在污染,但与钢包渣、中间包渣对钢水相比所占比重很小。因此,需要从吹炼工艺、钢包下渣量以及保护渣方面进行优化。

The contents of oxygen and nitrogen,the type of micro-inclusions,size,quantity and distribution of the evolution process of Q195 steel produced by a steel mill were systematically analyzed.The results show that the concentrations of micro-inclusions in slab are high and the secondary oxidation is serious.The micro-inclusions are complex inclusions such as Al2O3-SiO2-MnO,FeO-Al2O3 and so on,and trace elements such as Ce and La are found.The molten steel is obviously polluted by ladle slag and tundish slag.The proportion of Na and K as micro-inclusions is only 10%,it indicates that the molten steel is polluted by mold powder in the mold,but the proportion of slag and tundish slag to the molten steel is small.Therefore,it is necessary to optimize the blowing process,the amount of slag and mold powder.