摘要
采用铁水脱硫-转炉-LF炉-RH-钙处理-连铸工艺路线，出钢采用A1脱氧，造高碱度低氧化性精炼渣，生产X80管线钢。研究了精炼过程中夹杂物的成分、尺寸、形貌和数量等变化情况，确定了钢中夹杂物在不同特炼环节的变化规律，探讨了夹杂物中MgO和CaO的来源。结果表明，采用该冶炼工艺路线所生产的管线钢总氧的质量分数在10×10^-6～12×10^-6，钢中20μm以下夹杂物所占比例达到了90％，钢水具有很高的洁净度水平。在精炼过程中夹杂物MgO质量分数逐渐降低、CaO质量分数逐渐增加，精炼结束后钢中夹杂物为球形MgO—Al2O3 CaO类夹杂物，MgO、Al2O3和CaO质量分数平均分别2．6％、53．7％和43．7％，该类夹杂物外层为CaS，在精炼钢水温度下为液态，表明钢中夹杂物得到了有效的变性处理。在钢中夹杂物去除效果方面，软吹氩工艺对于10htm以下夹杂物的去除效果最好，去除率达到了81％。
X80 pipeline steel was produced with BOF-LF-RH-CC routine. During tapping aluminum was used to kill the liquid steel and high basicity and low oxidizing slag was made. The characteristics of non metallic inclusions in steel were studied during secondary refining process. The results showed that after the secondary refining process the total oxygen content of steel is between 10×10^-6 and 12 ×10^-6. The proportion of inclusions with a size less than 20μm reached 90%. During the secondary refining process the content of MgO in inclusions decreased while the content of CaO increased gradually. After refining of steel the inclusions mainly contain MgO, Al2O3 and CaO, the average content of which amounts to 2.6% ,53.7% and 43.7% respectively. These inclusions were covered with CaS and were liquid in molten steel, which infers that the inclusions were effectively modified. Soft bubbling of liquid steel after Ca treatment was proved to be an efficient way to remove fine inclusions from steel, with which 81% of inclusions smaller than 10 μm were removed.
出处
《中国冶金》
CAS
2010年第9期17-21,33,共6页
China Metallurgy
关键词
管线钢
夹杂物
二次精炼
软吹氲
pipeline steel
non-metallic inclusion
secondary refining
soft bubbling
