IF钢开浇过程中铸坯洁净度分析  

RESEARCH ON CLEANNESS OF IF STEEL SLAB PRODUCED IN START CASTING PROCESS

作　　者：高福彬 李建文 靖振权 周丹 Gao Fubin;Li Jianwen;Jing Zhenquan;Zhou Dan(Handan Iron and Steel Company,Hebei Iron and Steel Group)

机构地区：[1]河钢集团邯钢公司

出　　处：《河南冶金》2018年第5期5-9,共5页Henan Metallurgy

摘　　要：为了分析开浇过程对IF钢铸坯洁净度的影响,采用气体分析、成分分析、大型夹杂物分析等方法对"BOFRH-CC"工艺生产的IF钢的头坯的洁净度变化情况进行了分析。结果表明,沿铸坯的拉坯方向,钢中氮含量、全氧含量呈逐渐降低趋势,到距铸坯头部7.5 m时,氮含量降至0.003 1%以下,全氧含量降至0.002 4%以下;碳含量沿拉坯方向逐渐减少,到距头部8.5 m时降至0.003 0%以下,酸溶铝含量随拉坯方向逐渐升高,到据铸坯8.5 m时开始稳定,这与铸坯内全氧含量变化情况相吻合;铸坯前5.5 m内大型夹杂物的数量较高,均在2.0 mg/10kg以上,前3.5 m内发现尺寸≥300μm的大型夹杂,在距铸坯头部8.5 m后数量降至1.01 mg/10kg,尺寸在140μm以下;大型夹杂物的种类主要为硅铝酸盐、纯氧化铝、纯二氧化硅、铝钙复合夹杂等,其主要来源为保护渣卷渣、钢中三氧化铝的析出、浸入式水口内壁的附着物的冲刷及覆盖剂卷渣。结合以上信息可知,第一块合格铸坯应在距铸坯头部8.5 m后取。In order to analyze the effect of casting process on the cleanliness of IF steel slab,the cleanliness of IF steel slab of start casting process produced by“BOF-RH-CC”process was analyzed by gas analysis,composition analysis and large inclusions analysis.The results show that,along the casting direction of the steel slab,the N and T[O]in the steel gradually decrease.When the distance from the cast blank head is 7.5 m,the content of N is reduced to below 0.003 1%,and the content of T[O]is reduced to below 0.002 4%.The content of carbon decreases gradually along the direction of drawing,down to less than 0.003 0%when the distance from the head is 8.5 m,and the content of Als increases with the direction of the blank,which is stable to the slab 8.5 m,this is in accordance with the change of T[O]content in the steel slab.The number of large inclusions in the top 5.5 m of the steel slab is higher than 2.0 mg/10kg.The large inclusions with the size of more than 300μm are found in the front 3.5 m,and the number of the inclusions in the head of the slab is reduced to 1.01 mg/10kg and the size is below 140μm.The main types of large inclusions are aluminosilicate,pure alumina,pure silica and aluminum calcium composite inclusions.The main sources are the slag reel,the precipitation of Al 2O 3 in steel,the erosion of the attached material on the inner wall of the submerged nozzle and the covering agent slag.According to the above information,the first qualified steel slab should start at 8.5 m after pouring.

关 键 词：IF钢 头坯 洁净度 非稳态浇注 

分 类 号：TF777[冶金工程—钢铁冶金]