RH强制脱碳与自然脱碳工艺生产IF钢精炼效果分析

袁保辉; 刘建华; 周海龙; 黄基红; 张硕; 申志鹏

doi:10.13374/j.issn2095-9389.2020.10.10.002

RH强制脱碳与自然脱碳工艺生产IF钢精炼效果分析

doi: 10.13374/j.issn2095-9389.2020.10.10.002

1.
北京科技大学工程技术研究院，北京 100083
2.
攀钢集团西昌钢钒有限公司，西昌 615032

基金项目: 国家自然科学基金资助项目（51874028）

详细信息

通讯作者:
E-mail：liujianhua@metall.ustb.edu.cn

中图分类号: TF769.9
计量
- 文章访问数: 414
- HTML全文浏览量: 107
- PDF下载量: 33
- 被引次数: 0
出版历程
- 收稿日期: 2020-10-10
- 网络出版日期: 2020-12-11
- 刊出日期: 2021-08-25

Refining effect of IF steel produced by RH forced and natural decarburization process

1.
Institute of Engineering Technology, University of Science and Technology Beijing, Beijing 100083, China
2.
Xichang Steel & Vanadium Co. LTD of Pangang Group, Xichang 615032, China

More Information

Corresponding author: E-mail: liujianhua@metall.ustb.edu.cn

摘要

摘要: 西昌钢钒厂由于转炉热量不足而以转炉—LF精炼—RH精炼—连铸工艺生产IF钢，为探究RH强制脱碳与自然脱碳工艺生产IF钢精炼效果，采用生产数据统计、氧氮分析、夹杂物自动扫描、扫描电镜和能谱分析等手段，对不同脱碳工艺对顶渣氧化性以及钢的洁净度影响进行了详细研究。结果表明：（1）与自然脱碳工艺炉次相比，采用强制脱碳工艺的炉次在转炉结束与RH进站钢中的平均[O]含量更低；（2）两种工艺脱碳结束钢中的[O]含量基本在同一水平；（3）强制脱碳工艺的炉次在RH结束时渣中平均T.Fe的质量分数降低了1.3%。在能满足RH脱碳效果的前提下，尽量提高转炉终点钢液碳含量、降低钢液氧含量，后续在RH精炼时采用强制吹氧脱碳工艺，适当增大吹氧量来弥补钢中氧，可显著降低IF钢顶渣氧化性。自然脱碳工艺与强制脱碳工艺控制热轧板T.O含量均比较理想；与自然脱碳工艺相比，强制脱碳工艺可有效降低IF钢[N]含量，这与强制脱碳工艺真空室内碳氧反应更剧烈所导致的CO气泡更多和气液反应面积更大有关。脱碳工艺对IF钢热轧板中夹杂物类型、尺寸及数量没有明显影响，夹杂物主要由Al₂O₃夹杂、Al₂O₃–TiO_x夹杂与其他类夹杂物组成，以夹杂物的等效圆直径表示夹杂物尺寸，以上三类夹杂物平均尺寸分别为4.5、4.4和6.5 μm，且钢中尺寸在8 μm以下的夹杂物数量占比高于75%。在RH精炼过程中，尽量降低RH脱碳结束钢中[O]含量，有利于提高钢液洁净度。
- IF钢 /
- RH精炼 /
- 顶渣氧化性 /
- 洁净度 /
- 夹杂物 /
- 脱碳工艺
Abstract: Owing to insufficient converter heat, IF steel is produced via the BOF—LF—RH—CC process in the Xichang Steel & Vanadium Co.LTD of Pangang Group, Xichang, China. To explore the refining effect of IF steel produced via the RH forced and natural decarburization process, this work employed standard analysis methods such as production data statistics, total oxygen and nitrogen analysis, automatic scanning electron microscopy, scanning electron microscopy, and energy spectroscopy. The effects of different decarburization processes on the ladle slag oxidability and cleanliness of steel were investigated in detail. Compared with the natural decarburization process heats, results show that the forced decarburization process heats exhibit (1) lower average [O] content in molten steel after BOF and before RH, (2) a similar level of the [O] content in molten steel after decarburization with that of the natural decarburization process, and (3) 1.3% lower average T.Fe mass fraction in the ladle slag after RH treatment. To ensure the RH decarburization effect, the final carbon content increased and molten steel oxygen content reduced in the converter to the maximum extent. The forced oxygen blowing decarburization process was then used to compensate for the molten steel oxygen content during RH refining by increasing oxygen blowing properly, which can significantly decrease the ladle slag oxidability of IF steel. Both the natural decarburization and forced decarburization processes are ideal for controlling the T.O content of a hot–rolled sheet. Compared with the natural decarburization process, the forced decarburization process can effectively reduce the [N] content of IF steel, which is related to a more violent carbon–oxygen reaction in a vacuum chamber, resulting in a high volume of CO bubbles and a large gas–liquid reaction area. The decarburization process has no obvious influence on the type, size, and number of inclusions in the hot–rolled sheet of IF steel that mainly consist of Al₂O₃, Al₂O₃–TiO_x, and other inclusions. The average sizes of the above three 4.5, 4.4, and 6.5 μm, respectively, according to the equivalent circle diameter of inclusions. In addition, more than 75% of inclusions are within 8 μm. During the RH refining process, reducing the [O] content in molten steel after RH decarburization to the maximum extent is beneficial to improve the cleanliness of molten steel.
- IF steel /
- RH refining /
- ladle slag oxidability /
- cleanliness /
- inclusions /
- decarburization process

HTML全文

图 1 试样加工示意图

Figure 1. Sampling scheme for the hot–rolled sheet

下载: 全尺寸图片幻灯片

图 2 不同RH脱碳工艺钢中[O]含量和RH结束渣中T.Fe含量分布

Figure 2. Distribution of [O] content in molten steel and T.Fe content in the ladle slag after the RH treatment in different RH decarburization processes

下载: 全尺寸图片幻灯片

图 3 不同吹氧量时各工序钢中[O]和RH结束渣中T.Fe变化

Figure 3. Changes of [O] content in molten steel of the different processes and T.Fe content in the ladle slag after the RH treatment for different oxygen blowing conditions

下载: 全尺寸图片幻灯片

图 4 不同脱碳工艺炉次钢中T.O和[N]含量变化。（a）自然脱碳；（b）强制脱碳

Figure 4. Total oxygen and nitrogen changes in different decarburization process heats: (a) natural decarburization process; (b) forced decarburization process

下载: 全尺寸图片幻灯片

图 5 自然脱碳工艺炉次1钢中夹杂物的典型形貌。（a）Al₂O₃夹杂物；（b）Al₂O₃−TiO_x夹杂物；（c）CaO−Al₂O₃−TiO_x、MgO−Al₂O₃、MgO−Al₂O₃−TiO_x夹杂物

Figure 5. Typical morphologies of inclusions in the natural decarburization process of Heat 1：(a) Al₂O₃ inclusions; (b) Al₂O₃–TiO_x inclusions; (c) CaO–Al₂O₃–TiO_x, MgO–Al₂O₃–TiO_x, and MgO–Al₂O₃ inclusions

下载: 全尺寸图片幻灯片

图 6 强制脱碳工艺炉次4钢中夹杂物的典型形貌。（a）Al₂O₃夹杂物；（b）Al₂O₃−TiO_x夹杂物；（c）CaO−Al₂O₃−TiO_x、CaO−Al₂O₃、CaO−Al₂O₃−TiO_x夹杂物

Figure 6. Typical morphologies of inclusions in the forced decarburization process of Heat 4: (a) Al₂O₃ inclusions; (b) Al₂O₃–TiO_x inclusions; (c) CaO–Al₂O₃–TiO_x, CaO–Al₂O₃, and CaO–Al₂O₃–TiO_x inclusions

下载: 全尺寸图片幻灯片

图 7 夹杂物的能谱面扫图。（a）Al₂O₃夹杂物；（b）Al₂O₃–TiO_x夹杂物；（c）MgO–Al₂O₃–TiO_x夹杂物；（d）CaO–Al₂O₃–TiO_x夹杂物

Figure 7. Elemental mapping of inclusions: (a) Al₂O₃; (b) Al₂O₃–TiO_x; (c) MgO–Al₂O₃–TiO_x; (d) CaO–Al₂O₃–TiO_x

下载: 全尺寸图片幻灯片

图 8 不同脱碳工艺各类夹杂物尺寸分布箱型图

Figure 8. Size changes and distribution of inclusions in different decarburization processes

下载: 全尺寸图片幻灯片

图 9 不同脱碳工艺炉次各类夹杂物数量密度变化。（a）自然脱碳；（b）强制脱碳

Figure 9. Number density changes of inclusions in different decarburization process heats: (a) natural decarburization process; (b) forced decarburization process

下载: 全尺寸图片幻灯片

图 10 RH脱碳结束钢中[O]与钢中夹杂物的数量关系

Figure 10. Relationship between the number of inclusions and [O] content in molten steel after RH decarburization

下载: 全尺寸图片幻灯片

表 1 试验炉次RH过程工艺参数

Table 1. Process parameters of experimental heats during the RH treatment

Decarburization process	Heats	Oxygen blowing/ m³	[C] content in steel after decarburization/ 10⁻⁶	[O] content in steel after decarburization/ 10⁻⁶
Natural decarburization	1	0	18	277
	2	0	11	284
	3	0	15	290
Forced decarburization	4	15	13	285
	5	10	10	262
	6	60	10	306

下载: 导出CSV

表 2 自然脱碳与强制脱碳工艺脱碳效果比较

Table 2. Comparison of the decarburization effects between the natural and forced decarburization processes

Decarburization process	[C]_ave content in steel after BOF/10⁻⁶	[C]_ave content in steel before RH/10⁻⁶	[C]_ave content in steel after decarburization/10⁻⁶	RH decarburization time/min	RH treatment time/min
Natural decarburization	420	305	11.1	20	32
Forced decarburization	490	344	11.8	21	33
Note: The subscript ave represents the average content in this work.

下载: 导出CSV

参考文献(33)

[1]	Wang X H. Non-metallic inclusion control technology for high quality cold rolled steel sheets. Iron Steel, 2013, 48(9): 1 王新华. 高品质冷轧薄板钢中非金属夹杂物控制技术. 钢铁, 2013, 48(9):1
[2]	Sun Q, Lin Y, Li W D. Decarburization treatment and inclusion control during RH refining. J Univ Sci Technol Beijing, 2011(S1): 142 孙群, 林洋, 李伟东. RH精炼脱碳与夹杂物控制. 北京科技大学学报, 2011(S1):142
[3]	Yue F, Cui H, Li P H, et al. Study on the optimum process of refining ULC steel by RH degasser. J Univ Sci Technol Beijing, 2009(S1): 53 岳峰, 崔衡, 李朋欢, 等. RH冶炼超低碳钢的最优工艺研究. 北京科技大学学报, 2009(S1):53
[4]	Ma H X, Wang X H, Huang F X, et al. Effect of deoxidation technology on cleanliness of low carbon aluminum killed steel. Iron Steel, 2016, 51(1): 19 马焕珣, 王新华, 黄福祥, 等. 脱氧工艺对低碳铝镇静钢洁净度的影响. 钢铁, 2016, 51(1):19
[5]	Yuan P, Li H B, Luo Y Z, et al. Influence of ladle slag oxidability on the cleanliness of ultra low carbon steel. Chin J Eng, 2016, 38(12): 1702 苑鹏, 李海波, 罗衍昭, 等. 超低碳钢顶渣氧化性对钢液洁净度的影响. 工程科学学报, 2016, 38(12):1702
[6]	Shu H F, Liu L, Liu X H. Influence of slag denaturalization on inclusions in IF steel. Steelmaking, 2016, 32(3): 55 舒宏富, 刘浏, 刘学华. 钢包顶渣改质对IF钢夹杂物的影响. 炼钢, 2016, 32(3):55
[7]	Peng Z G, Qi J H, Yang C W. Influence of slag denaturalization on inclusions in IF steel. Chin J Eng, 2018(S1): 174 彭著刚, 齐江华, 杨成威. 顶渣改质工艺对IF钢夹杂物的影响. 工程科学学报, 2018(S1):174
[8]	Wang M, Bao Y P, Cui H, et al. Effect of RH pure circulation on the cleanness of titanium stabilized interstitial-free(Ti-IF) steel. J Univ Sci Technol Beijing, 2011, 33(12): 1448 王敏, 包燕平, 崔衡, 等. RH纯循环对Ti-IF钢洁净度的影响. 北京科技大学学报, 2011, 33(12):1448
[9]	Cui H, Chen B, Wang M, et al. Cleanliness control of IF steel during the RH refining process. J Univ Sci Technol Beijing, 2011(S1): 147 崔衡, 陈斌, 王敏, 等. RH精炼过程中IF钢洁净度控制. 北京科技大学学报, 2011(S1):147
[10]	Li Y H, Bao Y P, Shen X W, et al. Inclusions control study of DC06 steel in 300 t ladle. Steelmaking, 2014, 30(2): 38 李怡宏, 包燕平, 申小维, 等. 300 t钢包内DC06钢的夹杂物控制研究. 炼钢, 2014, 30(2):38
[11]	Cui H, Tian E H, Chen B, et al. Cleanliness study of IF steel by holding in ladles after RH vacuum process. Chin J Eng, 2014(S1): 32 崔衡, 田恩华, 陈斌, 等. RH真空精炼后IF钢镇静工艺的洁净度研究. 工程科学学报, 2014(S1):32
[12]	Cui A M, Wang J W, Liu B S, et al. The comparative study on the natural decarburization effect by RH and the forced decarburization effect by RH-TOP. Shou Gang Sci Technol, 2010(4): 24 崔爱民, 王建伟, 刘柏松, 等. RH精炼自然脱碳和TOP强制脱碳效果的对比研究. 首钢科技, 2010(4):24
[13]	Li P H, Bao Y P, Yue F, et al. Mechanism of carbon and oxygen reaction in RH decarburization of ultra low oxygen steel. J Univ Sci Technol Beijing, 2011, 33(7): 823 李朋欢, 包燕平, 岳峰, 等. RH脱碳过程中极低氧钢水的碳氧反应机理. 北京科技大学学报, 2011, 33(7):823
[14]	Liu B S, Li B H, Zhu G S, et al. Experimental investigation on conventional RH and RH-TOP refining process for IF steel production. Iron Steel, 2010, 45(8): 33 刘柏松, 李本海, 朱国森, 等. 常规RH和RH-TOP工艺精炼IF钢试验研究. 钢铁, 2010, 45(8):33
[15]	Li D M, Zhang W H, Lin L P, et al. Application of RH oxygen top-blowing technology in No.2 Steel-making Plant, WISCO. Steelmaking, 2007, 23(6): 5 doi: 10.3969/j.issn.1002-1043.2007.06.002 李大明, 张文辉, 林立平, 等. RH顶吹氧技术在武钢第二炼钢厂的应用. 炼钢, 2007, 23(6):5 doi: 10.3969/j.issn.1002-1043.2007.06.002
[16]	Yuan B H, Liu J H, Zhou H L, et al. The vacuum decarburization process optimization study of high altitude RH refining equipment. Steelmaking, 2020, 36(4): 31 袁保辉, 刘建华, 周海龙, 等. 高海拔RH精炼装置真空脱碳工艺优化研究. 炼钢, 2020, 36(4):31
[17]	Liu M, Bai F Q, Chen S S, et al. Application of water irrush source standard set in mine water prevention. Miner Eng Res, 2014, 29(3): 30 刘猛, 白峰青, 陈少帅, 等. 水源判别标准集在矿井防治水中的应用. 矿业工程研究, 2014, 29(3):30
[18]	Xu M, Liu Z C, Yan X, et al. Online detection method for incremental capacity internal resistance consistency. Energy Storage Sci Technol, 2019, 8(6): 1197 徐敏, 刘中财, 严晓, 等. 容量增量内阻一致性在线检测方法. 储能科学与技术, 2019, 8(6):1197
[19]	Hong J C, Wang Z P, Liu P. Big-data-based thermal runaway prognosis of battery systems for electric vehicles. Energies, 2017, 10(7): 919 doi: 10.3390/en10070919
[20]	Duan F C, Wu H Z. The production practice of ultra-low-carbon steel in thin slab continuous casting. Ind Heat, 2007, 36(6): 73 doi: 10.3969/j.issn.1002-1639.2007.06.027 段富春, 吴华章. 薄板坯连铸超低碳钢生产实践. 工业加热, 2007, 36(6):73 doi: 10.3969/j.issn.1002-1639.2007.06.027
[21]	Song M T, Li M G, Yu H C. Research on refining process of ultra-low-carbon steel for thin slab casting. Steelmaking, 2009, 25(3): 8 宋满堂, 李明光, 于华财. 超低碳钢薄板坯连铸钢水精炼工艺的研究. 炼钢, 2009, 25(3):8
[22]	Shen C, Song C, Shu H F, et al. Research of ULC steel production route combining RH-LF refining and CSP line. Iron Steel, 2008, 43(5): 26 沈昶, 宋超, 舒宏富, 等. CSP批量生产超低碳钢的RH-LF双联工艺研究. 钢铁, 2008, 43(5):26
[23]	Liang Y J, Che Y C. Handle of Inorganic Thermody Namic Data. Shenyang: Northeast University Press, 1993 梁英教, 车荫昌. 无机物热力学数据手册. 沈阳: 东北大学出版社, 1993
[24]	Cheng G G, Zhao P, Xu X L, et al. Process of vacuum denitrogenation of steel. Iron Steel, 1999, 34(1): 16 doi: 10.3321/j.issn:0449-749X.1999.01.005 成国光, 赵沛, 徐学禄, 等. 真空下钢液脱氮工艺研究. 钢铁, 1999, 34(1):16 doi: 10.3321/j.issn:0449-749X.1999.01.005
[25]	Cao S. Control of end nitrogen content in smelting of ultra-low nitrogen steel with converter. Hebei Metall, 2015(10): 14 曹盛. 超低氮钢转炉终点氮含量控制. 河北冶金, 2015(10):14
[26]	Kitamura T, Miyamoto K, Tsujino R, et al. Mathematical model for nitrogen desorption and decarburization reaction in vacuum degasser. ISIJ Int, 1996, 36(4): 395 doi: 10.2355/isijinternational.36.395
[27]	Wang M, Bao Y P, Cui H, et al. The composition and morphology evolution of oxide inclusions in Ti-bearing ultra low-carbon steel melt refined in the RH process. ISIJ Int, 2010, 50(11): 1606 doi: 10.2355/isijinternational.50.1606
[28]	Tang F P, Chang G H, Li H, et al. Inclusions in ultra-low carbon steel. Iron Steel, 2007, 42(1): 20 唐复平, 常桂华, 栗红, 等. 超低碳钢钢中夹杂物的研究. 钢铁, 2007, 42(1):20
[29]	Dekkers R, Blanpain B, Wollants P, et al. A morphological comparison between inclusions in aluminium killed steels and deposits in submerged entry nozzle. Steel Res Int, 2003, 74(6): 351 doi: 10.1002/srin.200300197
[30]	Wang M, Bao Y P, Yang Q. Effect of Ferro-titanium alloying process on steel cleanness. J Univ Sci Technol Beijing, 2013, 35(6): 725 王敏, 包燕平, 杨荃. 钛合金化过程对钢液洁净度的影响. 北京科技大学学报, 2013, 35(6):725
[31]	Pan M, Yu H X, Ji C X, et al. Effect of oxygen blowing during RH treatment on the cleanliness of IF steel. Chin J Eng, 2020, 42(7): 846 潘明, 于会香, 季晨曦, 等. RH精炼过程中吹氧量对IF钢洁净度的影响. 工程科学学报, 2020, 42(7):846
[32]	Gao S, Wang M, Guo J L, et al. Evaluation of cleanliness and distribution of inclusions in the thickness direction of interstitial free(IF) steel slabs. Chin J Eng, 2020, 42(2): 194 高帅, 王敏, 郭建龙, 等. IF钢铸坯厚度方向夹杂物分布及洁净度评估. 工程科学学报, 2020, 42(2):194
[33]	Stone R P, Jr. Figas R M, Branion R V. Productivity improvements in steelmaking via sensor-based steelmaking process control. Iron Steel Technol, 2006, 3(1): 31