| X80管线钢精炼过程夹杂物形成与演变 |
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| 引用本文： | 钟华军,姜敏,王章印,刘帅,姜金星,王新华. X80管线钢精炼过程夹杂物形成与演变[J]. 工程科学学报, 2023, 45(1): 98-106. DOI: 10.13374/j.issn2095-9389.2022.05.23.007 |
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| 作者姓名： | 钟华军 姜敏 王章印 刘帅 姜金星 王新华 |
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| 作者单位： | 1.北京科技大学冶金与生态工程学院，北京 100083 |
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| 基金项目： | 国家重点研发计划资助项目（2021YFB3401001）；中央高校基本科研业务费资助项目（FRF-DF-20-08） |
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| 摘 要： | 通过工业试验取样研究了X80管线钢精炼过程夹杂物的类型、尺寸、成分等变化规律，并结合FactSage8.1软件对钙处理和钢液冷却凝固过程夹杂物的演变机理进行了热力学计算分析.试验结果表明，LF精炼结束时夹杂物主要为MgO–Al2O3和MgO–Al2O3–CaO，数量占比分别为25%、75%，其尺寸主要分布在1～5μm之间，且1～2μm和2～5μm的夹杂物比例分别为56.0%、37.3%;RH精炼中T[O]、[N]质量分数分别由LF精炼结束时的0.0022%、0.0059%降低至0.0010%、0.0035%，夹杂物数量密度由LF结束约23.07 mm–2降低至7.44 mm–2，夹杂物去除率约67.8%；钙处理时，夹杂物主要为MgO–Al2O3–CaO和CaS–Al2O3–CaO系，夹杂物中CaS平均质量分数由RH精炼结束时的8%增加至36%,CaO平均质量分数由24%减少至12%；软吹结束时，尺寸<40μ...
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| 关 键 词： | X80 夹杂物 钙处理 精炼渣 冷却凝固 热力学 |
| 收稿时间： | 2022-05-23 |
Formation and evolution of inclusions in the refining process of X80 pipeline steel |
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| Affiliation: | 1.School of Metallurgy and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China2.Plate Plant of Nanjing Iron and Steel Co., Ltd., Nanjing 210000, China |
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| Abstract: | To further meet the requirements for using pipeline steel in extreme environments and to improve its safety in service, the inclusion control level in pipeline steel urgently needs improvement. In this paper, the variation laws of inclusion type, size, and composition in the refining process of X80 pipeline steel were studied through industrial trial sampling, and the evolution mechanism of inclusions during calcium treatment and steel cooling and solidification was analyzed using thermodynamic calculations with FactSage 8.1 software. The trial results showed mainly MgO–Al2O3 and MgO–Al2O3–CaO inclusions after LF refining in proportions of 25% and 75%, respectively, with sizes mainly distributed between 1–5 μm, and the proportion of inclusions of 1–2 μm and 2–5 μm were 56.0% and 37.3%, respectively. The contents of T[O] and [N] were reduced from 0.0022% and 0.0059% after LF refining to 0.0010% and 0.0035% after RH refining, respectively, and the number density of inclusions was reduced from approximately 23.07 mm?2 after LF to 7.44 mm?2, with an inclusions removal rate of approximately 67.8%. The inclusions were mainly MgO?Al2O3–CaO and CaS–Al2O3–CaO systems during calcium treatment, the average CaS content in the inclusions increased from 8% after RH refining to 36%, and the average CaO content decreased from 24% to 12%. After soft blowing, the SiO2 content ranged from 0 to 2.5% in the inclusions smaller than 40 μm and from 6.0% to 8.0% in the inclusions larger than 40 μm, and the inclusions larger than 40 μm were mainly CaO–Al2O3–MgO–SiO2, whose chemical composition is essentially identical to that of the refining slag, whose source is the refining slag involved; thermodynamic calculations show that when the [Ca] content is between 10.5×10–6–15.8×10–6, all spinel inclusions are modified, and all the inclusions are liquid calcium aluminates; when the steel is at casting temperature, the inclusions are mainly liquid calcium aluminates, and when the temperature is lowered to 1428 ℃, the liquid inclusions completely transform into solid. As the temperature drops below 1309 ℃, the type of inclusions essentially remains constant. During the entire temperature drop, the CaO content in the inclusions decreased, and the CaS content increased. |
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