高级别管线钢超低硫控制研究

Controlling of Super-Low Sulfide of High Grade Pipeline Steel

利用光学碱度计算了1873 K时CaO-Si O2-Al2O3-MgO(10%)四元精炼渣系的硫容量,从理论上分析了精炼高级别管线钢超低硫控制的工艺条件,绘制出精炼渣硫容量、渣中硫、钢中溶解氧与钢中硫的关系图。分析了某钢厂LF-VD高级别管线钢生产工艺,LF1(LF炉精炼初期)、LF2(LF炉精炼末期)和VD精炼渣的氧化能力w((MnO+FeO))分别为11.92%、2.00%和1.10%,精炼渣碱度分别为3.195、6.250和7.600,精炼渣的曼内斯曼指数M(R/w(Al2O3))分别为0.09、0.17和0.18,精炼渣硫容量C′S分别为0.010、0.022和0.023。钢中硫的质量分数从LF1的80×10-6,降低到LF2的(20～30)×10-6,并稳定在VD末期的20×10-6以下,与理论计算相符。

The variation of sulfide capacity with composition in the slag system CaO-SiO2-Al2O3-MgO（10 % ） at 1873 K was calculated by using the optical basicity. The high grade pipeline steel refining process arts to control superlow sulphide are analysised and the relationship figure of sulphide capacity, （% S）, [ %O] and [ % S] is drawn. A LF-VD refining process was analysised. During the process of LF1（the primary state of LF process）, LF2（the end of LF process） and VD, the （MnO＋FeO） content of top-slag are 11.92 %, 2.00% and 1.1% ; the basicity（R） of top-slag are 3. 195, 6.25 and 7.6; The M number （R/Al2O3） of top-slag are 0.09, 0.17 and 0.18; the sulfide capacity（Cs＇） of top-slag are 0.01, 0. 022 and 0. 023. And the [%S] of steel are 80×10^-6 during LF1, （20-30） ×10^-6 during LF2, and below 20×10^-6 during VD, which is consistented with the calculating result.