管线钢及其连铸坯夹杂物钙处理改性  

Calcium treatment modification of inclusions in pipeline steel and its continuous casting slabs

作　　者：刘冀伟 王伟健 任英[1] 代平 李世良 张立峰 LIU Jiwei;WANG Weijian;REN Ying;DAI Ping;LI Shiliang;ZHANG Lifeng(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Mechanical and Material Engineering,North China University of Technology,Beijing 100144,China;Rizhao Co.,Ltd.,Shandong Iron and Steel Group,Rizhao 276800,Shandong,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]北方工业大学机械与材料工程学院,北京100144 [3]山东钢铁集团日照有限公司,山东日照276800

出　　处：《中国冶金》2024年第9期68-77,共10页China Metallurgy

基　　金：国家重点研发计划资助项目(2023YFB3709900);国家自然科学基金资助项目(U22A20171)。

摘　　要：管线钢的生产普遍运用钙处理技术,本试验主要探究钙处理程度对钢液以及连铸坯中非金属夹杂物改性的影响。研究结果表明,随着钢液中TCa的质量分数从0.000 5%增加到0.002 0%,钢中非金属夹杂物的平均成分先靠近液相区后远离液相区,并且钢中Al_(2)O_(3)夹杂物的质量分数由68.14%减小到48.89%,同时CaO夹杂物的质量分数由21.8%增加到27.8%;连铸坯中非金属夹杂物的平均尺寸从4.02μm减小到3.83μm,非金属夹杂物数密度在钢液中TCa质量分数为0.002 0%时为6.61个/mm^(2),为最小值。通过Factsage热力学计算得到,管线钢连铸坯中MnS质量分数随着钢液中钙含量的增加由10.65%减小到4.84%,MnS夹杂物的析出温度由1 340℃降低到1 220℃,热力学计算与工业试验得出的结果有一致性。The calcium treatment technology is widely used in the production of pipeline steel. The effect of calcium treatment degree on the modification of non-metallic inclusions in the molten steel and continuous casting slab was studied. It is indicated that as the mass fraction of TCa in the molten steel increases from 0.000 5% to 0.002 0%, the average composition of non-metallic inclusions in the steel initially approaches the liquid phase region and then away from it. Moreover, the mass fraction of Al_(2)O_(3) inclusions in the steel decreases from 68.14% to 48.89%, while the mass fraction of CaO inclusions increases from 21.8% to 27.8%. The average size of non-metallic inclusions in the continuous casting slab decreases from 4.02 μm to 3.83 μm, and the number density of non-metallic inclusions reaches a minimum value of 6.61 /mm^(2) when the mass fraction of TCa in the steel is 0.002 0%. Thermodynamic calculations were performed by Factsage to investigate the transformation of inclusions during the solidification process. It is showed that the mass fraction of MnS in the continuous casting slab of pipeline steel decreases from 10.65% to 4.84% as the calcium content in the molten steel increases. Additionally, the precipitation temperature of MnS inclusions decreases from 1 340 oC to 1 220 oC. The results obtained from thermochemical calculations are consistent with those from industrial experiments.

关 键 词：管线钢 钙处理 非金属夹杂物 连铸坯 热力学计算 

分 类 号：TF777[冶金工程—钢铁冶金]