Morphology evolution and formation mechanism of Al–Ti–O inclusions in an ultra low carbon steel

HUANG Ri-kang; JIANG Ren-bo; ZHOU Qiu-yue; REN Ying; JIANG Dong-bin; ZHANG Li-feng

doi:10.13374/j.issn2095-9389.2022.03.02.001

Volume 45 Issue 5

May 2023

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HUANG Ri-kang, JIANG Ren-bo, ZHOU Qiu-yue, REN Ying, JIANG Dong-bin, ZHANG Li-feng. Morphology evolution and formation mechanism of Al–Ti–O inclusions in an ultra low carbon steel[J]. Chinese Journal of Engineering, 2023, 45(5): 755-764. doi: 10.13374/j.issn2095-9389.2022.03.02.001

Citation:

HUANG Ri-kang, JIANG Ren-bo, ZHOU Qiu-yue, REN Ying, JIANG Dong-bin, ZHANG Li-feng. Morphology evolution and formation mechanism of Al–Ti–O inclusions in an ultra low carbon steel[J]. Chinese Journal of Engineering, 2023, 45(5): 755-764. doi: 10.13374/j.issn2095-9389.2022.03.02.001

Citation:

HUANG Ri-kang, JIANG Ren-bo, ZHOU Qiu-yue, REN Ying, JIANG Dong-bin, ZHANG Li-feng. Morphology evolution and formation mechanism of Al–Ti–O inclusions in an ultra low carbon steel[J]. Chinese Journal of Engineering, 2023, 45(5): 755-764. doi: 10.13374/j.issn2095-9389.2022.03.02.001

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Morphology evolution and formation mechanism of Al–Ti–O inclusions in an ultra low carbon steel

doi: 10.13374/j.issn2095-9389.2022.03.02.001

1.
Technology Center, Liuzhou Iron & Steel Co., LTD., Liuzhou 545002, China
2.
Steelmaking Plant of Tangshan Stainless Steel Co., Tangshan 063105, China
3.
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
4.
School of Mechanical and Materials Engineering, North China University of Technology, Beijing 100144, China

More Information

Corresponding author: REN Ying, E-mail: yingren@ustb.edu.cn; ZHANG Li-feng, E-mail: zhanglifeng@ncut.edu.cn
Received Date: 2022-03-02
Available Online: 2022-11-16
Publish Date: 2023-05-01

Abstract

Abstract

In the current study, Al–Ti–O inclusions after Ti-alloyed in an ultra-low carbon IF steel were analyzed. It was found that Al–Ti–O inclusions were classified into seven types based on their morphologies, including four types with an Al₂O₃ outer layer and the other three without the Al₂O₃ outer layer. Approximately 78.0% of Al–Ti–O inclusions had an Al₂O₃ outer layer. There was little separated TiO_x inclusion detected in the steel. Without the consideration of the Al₂O₃ layer of Al–Ti–O complex inclusions, the core of Al–Ti–O complex inclusions was generally similar to that without the Al₂O₃ outer layer. Compared with the sample at 1 minute after the Ti addition, the number density of Al–Ti–O inclusions without an Al₂O₃ outer layer in the sample at 4 minutes after the Ti addition decreased by 0.21 mm^?2, while the number density of Al–Ti–O inclusions with an Al₂O₃ outer layer increased by 0.19 mm^?2. After the titanium alloying process, a large number of Al–Ti–O inclusions without the Al₂O₃ outer layer were transiently generated. Further, the Al₂O₃ outer layer was formed on the surface of inclusions, leading to the increase of the percentage of Al–Ti–O inclusions with the Al₂O₃ outer layer to 78.0%. Thermodynamic calculated results show that the evolution route of inclusions was solid Al₂O₃ → liquid Al–Ti–O → solid Ti₂O₃ with the increase of titanium content in the steel. The inclusion of Al₂O₃ was the only stable phase in the liquid steel in equilibrium, while the high concentration of titanium in the local steel during the titanium alloying process led to the formation of titanium-containing oxides. When the oxygen content in the steel was lower than 0.03%, inclusions were mainly solid Al₂O₃. Inclusions containing TiO_x were formed with oxygen content in the local steel exceeding 0.03% during the reoxidation process. The formation mechanism of Al–Ti–O inclusions was divided into two steps. After the titanium alloying process in the refining, when the local titanium content in the steel was higher than 0.42%, the [Ti] reacted with the molten steel to transiently form Al₂O₃–TiO_x and TiO_x. With the mixing of the titanium in the molten steel, the generated TiO_x-containing oxides were reduced by [Al] in the steel. Inclusions of Al₂O₃?TiO_x and TiO_x gradually transformed to Al₂O₃ on the surface.
- ultra low carbon steel,
- Al–Ti–O inclusions,
- morphology classification,
- formation mechanism,
- RH refining

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References(27)

References

[1]	張立峰, 許中波, 靖雪晶, 等. IF鋼中碳、氮含量的控制. 連鑄, 1997, 22(6):35 Zhang L F, Xu Z B, Jing X J, et al. Control of carbon & nitrogen content in IF steel. Continuous Cast, 1997, 22(6): 35
[2]	許帥, 孫新軍, 梁小凱, 等. 高鈦耐磨鋼凝固組織中TiC析出相表征. 鋼鐵研究學報, 2021, 33(6):521 Xu S, Sun X J, Liang X K, et al. Characterization of TiC precipitation in high Ti wear-resistant steel solidification structure. J Iron Steel Res, 2021, 33(6): 521
[3]	李成剛, 周曉光, 蔣小冬, 等. 冷卻工藝對Ti微合金化高強鋼組織和硬度的影響. 鋼鐵研究學報, 2021, 33(9):987 doi: 10.13228/j.boyuan.issn1001-0963.20200202 Li C G, Zhou X G, Jiang X D, et al. Influence of cooling processes on microstructure and hardness of Ti micro-alloyed high strength steel. J Iron Steel Res, 2021, 33(9): 987 doi: 10.13228/j.boyuan.issn1001-0963.20200202
[4]	Basu S, Choudhary S K, Girase N U. Nozzle clogging behaviour of Ti-bearing Al-killed ultra low carbon steel. ISIJ Int, 2004, 44(10): 1653 doi: 10.2355/isijinternational.44.1653
[5]	隋亞飛, 孫國棟, 趙艷, 等. IF 鋼中含Ti夾雜物的衍變規律. 北京科技大學學報, 2014, 36(9):1174 Sui Y F, Sun G D, Zhao Y, et al. Evolution of titaniferous inclusions in IF steelmaking. J Univ Sci Technol Beijing, 2014, 36(9): 1174
[6]	Matsuura H, Wang C, Wen G H, et al. The transient stages of inclusion evolution during Al and/or Ti additions to molten iron. ISIJ Int, 2007, 47(9): 1265 doi: 10.2355/isijinternational.47.1265
[7]	段豪劍, 張立峰, 付俊偉, 等. 439鐵素體不銹鋼中TiN生成熱力學分析 // 2014年全國冶金物理化學學術會議論文集. 包頭, 2014 Duan H J, Zhang L F, Fu J W, et al. Thermodynamic analysis of TiN formation in 439 ferritic stainless steel // National Proceedings of Conference on Metallurgical Physical Chemistry. Baotou, 2014
[8]	王啟明, 成國光. 含Ti不銹鋼冶金工藝進展. 工程科學學報, 2021, 43(11):1447 Wang Q M, Cheng G G. Metallurgy development of Ti-stabilized stainless steel. Chin J Eng, 2021, 43(11): 1447
[9]	高帥, 王敏, 郭建龍, 等. IF鋼鑄坯厚度方向夾雜物分布及潔凈度評估. 工程科學學報, 2020, 42(2):194 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
[10]	王寶, 李任春, 劉俊山, 等. DC06 IF鋼精煉渣成分優化及鋼-渣中氧的控制. 鋼鐵研究學報, 2021, 33(4):293 Wang B, Li R C, Liu J S, et al. Composition optimization of DC06 IF steel refining slag and control of oxygen in steel and slag. J Iron Steel Res, 2021, 33(4): 293
[11]	劉振楠, 陶東平, 姚春玲, 等. 鈦微合金鋼爐外精煉相平衡研究與熱力學分析. 鋼鐵研究學報, 2019, 31(8):702 doi: 10.13228/j.boyuan.issn1001-0963.20190004 Liu Z N, Tao D P, Yao C L, et al. Phase equilibrium study and thermodynamic analysis on secondary refining process of titanium-microalloyed steel. J Iron Steel Res, 2019, 31(8): 702 doi: 10.13228/j.boyuan.issn1001-0963.20190004
[12]	張立峰. 鋼中非金屬夾雜物: 工業實踐. 北京: 冶金工業出版社, 2020 Zhang L F. Non-metallic Inclusions in Steels: Industrial Practice. Beijing: Metallurgical Industry Press, 2020
[13]	張立峰. 鋼中非金屬夾雜物: 基礎. 北京: 冶金工業出版社, 2019 Zhang L F. Non-metallic Inclusions in Steels: Fundamentals. Beijing: Metallurgical Industry Press, 2019
[14]	黃健, 閔義, 姜茂發, 等. IF鋼生產過程非金屬夾雜物的演變行為. 東北大學學報(自然科學版), 2013, 34(3):368 doi: 10.3969/j.issn.1005-3026.2013.03.016 Huang J, Min Y, Jiang M F, et al. Evolution of non-metallic inclusions during IF steel making process. J Northeast Univ, 2013, 34(3): 368 doi: 10.3969/j.issn.1005-3026.2013.03.016
[15]	李朋歡, 葉健松, 胡文豪, 等. 鈦合金化對鋁鎮靜鋼中夾雜物的影響. 鋼鐵研究學報, 2013, 25(10):20 Li P H, Ye J S, Hu W H, et al. Effect of Ti-alloyed on inclusions in Al-killed steel. J Iron Steel Res, 2013, 25(10): 20
[16]	Jung I H, Decterov S A, Pelton A D. Computer application of thermodynamic databases to inclusion engineering. ISIJ Int, 2004, 44(3): 527 doi: 10.2355/isijinternational.44.527
[17]	Li M G, Matsuura H, Tsukihashi F. Evolution of Al–Ti oxide inclusion during isothermal heating of Fe–Al–Ti alloy at 1573 K (1300 °C). Metall Mater Trans B, 2017, 48(3): 1915 doi: 10.1007/s11663-017-0968-y
[18]	張立峰, 李燕龍, 任英. 鋼中非金屬夾雜物的相關基礎研究(Ⅱ)——夾雜物檢測方法及脫氧熱力學基礎. 鋼鐵, 2013, 48(12): 1 Zhang L F, Li Y L, Ren Y. Fundamentals of non-metallic inclusions in steel: Part II. Evaluation method of inclusions and thermodynamics of steel deoxidation. Iron & Steel, 2013, 48(12): 1
[19]	Van Ende M A, Guo M X, Dekkers R, et al. Formation and evolution of Al–Ti oxide inclusions during secondary steel refining. ISIJ Int, 2009, 49(8): 1133 doi: 10.2355/isijinternational.49.1133
[20]	潘明, 于會香, 季晨曦, 等. RH精煉過程中吹氧量對IF鋼潔凈度的影響. 工程科學學報, 2020, 42(7):846 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
[21]	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
[22]	Doo W C, Kim D Y, Kang S C, et al. The morphology of Al–Ti–O complex oxide inclusions formed in an ultra low-carbon steel melt during the RH process. Met Mater Int, 2007, 13(3): 249 doi: 10.1007/BF03027813
[23]	顧超, 趙立華, 甘鵬. 超低碳鋼精煉過程中Fe–Al–Ti–O類復合氧化物夾雜的演變與控制. 工程科學學報, 2019, 41(6):757 Gu C, Zhao L H, Gan P. Revolution and control of Fe–Al–Ti–O complex oxide inclusions in ultralow-carbon steel during refining process. Chin J Eng, 2019, 41(6): 757
[24]	袁保輝, 劉建華, 周海龍, 等. RH強制脫碳與自然脫碳工藝生產IF鋼精煉效果分析. 工程科學學報, 2021, 43(8):1107 Yuan B H, Liu J H, Zhou H L, et al. Refining effect of IF steel produced by RH forced and natural decarburization process. Chin J Eng, 2021, 43(8): 1107
[25]	Qin Y M, Wang X H, Huang F X, et al. Influence of reoxidation by slag and air on inclusions in IF steel. Metall Res Technol, 2015, 112(4): 405 doi: 10.1051/metal/2015025
[26]	Mitsutaka H, Kimihisa I. Thermodynamic Data for Steelmaking. Sendai: Tohoku University Press, 2010
[27]	李寧, 王璐, 李承志, 等. 過共析簾線鋼中Ti夾雜的析出熱力學與形成機制. 鋼鐵研究學報, 2022, 34(3):200 doi: 10.13228/j.boyuan.issn1001-0963.20210115 Li N, Wang L, Li C Z, et al. Precipitation thermodynamics and formation mechanism of Ti inclusions in hypereutectoid tire cord steel. J Iron Steel Res, 2022, 34(3): 200 doi: 10.13228/j.boyuan.issn1001-0963.20210115