90t钢包渣线镁碳砖侵蚀原因分析与改进措施

Analysis of Corrosion Cause of MgO-C Brick for 90 t Ladle Slag Lines and Improvement Measures

针对莱钢90tLF-VD精炼钢包渣线镁碳砖严重侵蚀的问题,分析认为,主要原因是精炼熔渣侵蚀,真空及长时间的高温加速了侵蚀。通过优化精炼渣系,控制炉渣碱度在4.2～5.0,渣中FeO≤0.5%、MgO≥12%;选用高纯度电熔镁砂作原料,碳含量控制在14%,改进镁碳砖材质;LF炉采用埋弧造渣作业;VD炉采用分阶段氩气控制模式。渣线寿命由35次提高到50次。

The causes of serious corrosion of the MgO-C brick for 90 t LF-VD ladle slag lines were analyzed. The corrosion was caused mainly by refining slag and was accelerated by vacuum and high temperature for long time. Through optimizing refining slag system, the basicity was controlled in 4.2-4.5, the Fen content in refining slags〈0.5% and the MgO content in refining slags〉 12%. Selecting fused magnesia with high purity as raw materials, controlling the carbon content at 14%, the components of the MgO-C brick was improved; LF furnace adopted submerged-arc operation; VD furnace adopted phased argon control mode. The service life of slag hne brick increased to 50 heats from 35 heats.