摘要:
使用氧氮分析仪、金相显微分析仪、大样电解法、SEM与EDS等途径,对在转炉加块矿条件下采用KR-BOFAr-CC工艺生产的碳素结构钢Q235B钢的洁净度进行研究。结果表明:从氩站进站到连铸铸坯过程中,钢水中检测到的显微夹杂物数量总体减少,经过氩站吹氩处理后,显微夹杂物平均数量降低了26.63%,表明吹氩效果较明显;在各生产工序过程钢中主要的显微夹杂物为Al2O3和MnS,其中还包含少量CaO-MgO-Al2O3、CaO-Al2O3与MgO-Al2O3复合夹杂。在氩站精炼过程中,TO含量降低了19.60×10-6;在浇铸过程中,TO含量增加了10.55×10-6,这是由钢水发生二次氧化或卷渣引起的。从转炉到铸坯过程中,平均氮含量呈递增趋势,在转炉终点到氩站出站过程中增氮最为严重。主要的大型夹杂物为SiO2,还有少量的MgO-Al2O3-SiO2。
Abstract:
Oxygen and nitrogen analyzer,metallographic examination,SLIME,SEM and EDS techniques had been used to study the cleanliness of plain carbon structural steel Q235B produced via KR-BOF-ArCC process under the conditions of substituting iron ore for partial scarp in converter. The results show that the total amount of microscopic inclusions decreases from argon refining inlet to casting process. After argon refining,average number of microscopic inclusions decreases by 26.63%,indicating a significant effect from argon refining. Major microscopic inclusions at various steps are Al2O3 and Mn S as well as small amount of CaO-MgO-Al2O3,CaO-Al2O3 and MgO-Al2O3 composite inclusions. In the process of argon refining,TO content decreases by 19.60×10-6 while casting step makes TO content increase by 10.55 × 10-6 which is due to molten steel secondary oxidation or slag entrapment. From the converter to the casting process,the average nitrogen content gradually increases and maximum nitrogen increasing takes place during the convertor to argon refining process. The large inclusions are dominant SiO2 and small amount of MgO-Al2O3-SiO2.
点击查看大图
下载:
