超低碳鋼中Al?Ti?O夾雜物的形貌演變和生成機理

黃日康; 姜仁波; 周秋月; 任英; 姜東濱; 張立峰

doi:10.13374/j.issn2095-9389.2022.03.02.001

超低碳鋼中Al?Ti?O夾雜物的形貌演變和生成機理

doi: 10.13374/j.issn2095-9389.2022.03.02.001

1.
柳州鋼鐵股份有限公司技術中心，柳州 545002
2.
唐山不銹鋼有限責任公司煉鋼廠，唐山 063105
3.
北京科技大學冶金與生態工程學院，北京 100083
4.
北方工業大學機械與材料工程學院，北京 100144

基金項目: 國家自然科學基金資助項目（U1860206, 51725402）；河北省省級科技計劃資助項目（20311004D, 20591001D）

詳細信息

通訊作者:
任英，E-mail: yingren@ustb.edu.cn

張立峰，E-mail: zhanglifeng@ncut.edu.cn

中圖分類號: TF769.4
計量
- 文章訪問數: 549
- HTML全文瀏覽量: 223
- PDF下載量: 92
- 被引次數: 0
出版歷程
- 收稿日期: 2022-03-02
- 網絡出版日期: 2022-11-16
- 刊出日期: 2023-05-01

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

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

摘要

摘要: 對超低碳IF鋼鈦合金化后的非金屬夾雜物進行了分析，研究發現鈦合金化后的夾雜物主要為Al₂O₃和Al?Ti?O夾雜物，沒有發現純TiO_x夾雜物。鋼中生成的Al?Ti?O復合夾雜物從形貌上均可分為七種類型，四種具有Al₂O₃外層，另外三種無Al₂O₃外層。鈦合金化后，鋼中瞬態生成了大量無Al₂O₃外層的Al?Ti?O夾雜物，隨后夾雜物表面生成Al₂O₃外層，導致有Al₂O₃外層的Al?Ti?O夾雜物數量比例逐漸增加至78.0%。熱力學計算結果表明，隨著鋼中鈦含量的增加，夾雜物的轉變順序為固態Al₂O₃→液態Al?Ti?O→固態Ti₂O₃。確定了Al?Ti?O夾雜物的生成機理過程分為兩步：精煉過程鈦合金化后，當鋼液局部區域的鈦的質量分數高于0.42%時，[Ti]與鋼液反應瞬態生成Al₂O₃?TiO_x或TiO_x；隨著精煉過程中鈦元素的混勻，含TiO_x夾雜物被鋼中[Al]還原，Al₂O₃?TiO_x和TiO_x夾雜物逐漸轉變，在夾雜物表面生成Al₂O₃。
- 超低碳鋼 /
- AlTiO夾雜物 /
- 形貌分類 /
- 生成機理 /
- RH精煉
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

HTML全文

圖 1 樣品加工示意圖

Figure 1. Schematic diagram of the sample machining process

下載: 全尺寸圖片幻燈片

圖 2 精煉過程中鋼中夾雜物的變化. （a）夾雜物平均成分;（b）夾雜物數密度;（c）夾雜物平均尺寸;（d）夾雜物面積分數

Figure 2. Evolution of inclusions in the steel during the refining process: (a) average composition of oxide inclusions; (b) number density of oxide inclusions; (c) average diameter of oxide inclusions; (d) area fraction of oxide inclusions

Values in the horizontal axis: 1—before adding titanium；2—one minute after adding titanium；3—four minutes after adding titanium；4—RH refining end；5—half of the casting cycle

下載: 全尺寸圖片幻燈片

圖 3 精煉過程中鋼中夾雜物的成分和尺寸的關系. （a）加鈦前;（b）加鈦1 min;（c）加鈦4 min;（d）澆鑄一半

Figure 3. Relationship between the composition and size of inclusions in the steel during the refining process: (a) before adding titanium; (b) 1 min after adding titanium; (c) 4 min after adding titanium; (d) half of the casting cycle

下載: 全尺寸圖片幻燈片

圖 4 鋼中典型Al–Ti–O夾雜物類型. （a）類型一;（b）類型二;（c）類型三;（d）類型四;（e）類型五;（f）類型六;（g）類型七

Figure 4. Typical Al–Ti–O inclusions in the steel: (a) type 1; (b) type 2; (c) type 3; (d) type 4; (e) type 5; (f) type 6; (g) type 7

下載: 全尺寸圖片幻燈片

圖 5 各類Al–Ti–O夾雜物的數量對比

Figure 5. Comparison of the fraction of various Al–Ti–O inclusions

下載: 全尺寸圖片幻燈片

圖 6 有Al₂O₃外層和無Al₂O₃外層的Al–Ti–O復合夾雜物的數量變化

Figure 6. Number density of Al–Ti–O inclusions with and without Al₂O₃ outer layer

Values in the horizontal axis: 1—one minute after adding titanium；2—four minutes after adding titanium；3—RH refining end； 4—half of the casting cycle

下載: 全尺寸圖片幻燈片

圖 7 不同類型Al–Ti–O復合夾雜物隨時間的變化

Figure 7. Evolution of various types of Al–Ti–O composite inclusions with time

Values in the horizontal axis: 1—one minute after adding titanium；2—four minutes after adding titanium；3—RH refining end；4—half of the casting cycle

下載: 全尺寸圖片幻燈片

圖 8 1600 ℃下鋼液中Al–Ti–O系夾雜物的穩定區域圖

Figure 8. Equilibrium diagram for Al–Ti–O system in the liquid steel at 1600 ℃

下載: 全尺寸圖片幻燈片

圖 9 Al–Ti–O三元系的反應的吉布斯自由能的變化. （a）隨溫度的變化;（b）1600 ℃時隨鈦含量的變化

Figure 9. Changes in Gibbs free energy of Al–Ti–O ternary reaction: (a) with temperature; (b) with Ti content at 1600 ℃

下載: 全尺寸圖片幻燈片

圖 10 1600 ^oC下鋼中鈦含量和氧含量對夾雜物成分的影響. （a）鈦含量;（b）氧含量

Figure 10. Effect of Ti and O contents on the composition of inclusions in the liquid steel at 1600 ^oC: (a) titanium content; (b) oxygen content

下載: 全尺寸圖片幻燈片

圖 11 Al–Ti–O復合夾雜物形成機理示意圖

Figure 11. Schematic of the formation mechanism of Al–Ti–O inclusions

下載: 全尺寸圖片幻燈片

表 1 IF鋼化學成分（質量分數）

Table 1. Chemical composition of the IF steel %

C	Si	Mn	P	S	[Al]	T.Ti	T.N
0.0016	0.005	0.13	0.009	0.005	0.04	0.067	0.0025

下載: 導出CSV

表 2 不同工序鋼樣的總氧質量（質量分數）

Table 2. Total oxygen content of steel samples at different stages %

Process	Before adding titanium	1 min after adding titanium	4 min after adding titanium	RH refining end	Half of the casting cycle
T.O	0.0030	0.0031	0.0025	0.0026	0.0021

下載: 導出CSV

表 3 渣中TiO₂含量及鋼中夾雜物數密度變化

Table 3. Changes of TiO₂ content in slag and number density of inclusions in the steel

Process	TiO₂ mass fraction in slag/%	Number density of inclusions in the steel/mm^–2
Process	TiO₂ mass fraction in slag/%	Al–Ti–O	Type 1	Type 4	Type 2	Type 5	Type 3	Type 6
1 min after adding titanium	0.62	0.64	0.085	0.170	0.064	0.043	0.192	0.032
4 min after adding titanium	0.60	0.63	0.013	0.225	0.025	0.150	0.100	0.100
RH refining end	0.75	0.42	0.013	0.189	0.025	0.101	0.013	0.050
Half of the casting cycle	1.00	0.14	0	0.096	0.011	0.021	0	0.011

下載: 導出CSV

表 4 1600 ℃時鋼液中Al–Ti–O系的反應^{[9, 19, 26]}

Table 4. Reactions of Al–Ti–O system in the liquid steel at 1600 ℃^{[9, 19, 26]}

No.	Chemical reaction	Δ_r$G^{\ominus} $/(J·mol^–1)	Δ_rG/ (J·mol^–1)
1	2[Ti] + 3[O] = (Ti₂O₃)	$ - 1100392 + 356.7T$	>0
2	3[Ti] + 5[O] = (Ti₃O₅)	$ - 1774016 + 569.9T$	>0
3	[Ti] + 2[Al] + 5[O] = (Al₂TiO₅)	$ - 1406806 + 400.9T$	>0
4	[Ti] + (Al₂O₃) + 2[O] = (Al₂TiO₅)	$ - 181978 + 7.3T$	>0
5	2[Ti] + (Al₂O₃) = 2[Al] + (Ti₂O₃)	$124436 - 36.9T$	>0
6	9[Ti] + 5(Al₂O₃) = 10[Al] + 3(Ti₃O₅)	$802092 - 258.3T$	>0
7	3[Ti] + $5({\rm{Al}}_2{\rm{O}}_3) $ = 4[Al] + 3(Al₂TiO₅)	$ 26212.4 + 90.4T $	>0
8	2[Al] + 3[O] = (Al₂O₃)	$ - 1224828 + 393.6T$	<0
9	2[Al] + (Ti₂O₃) = 2[Ti] + (Al₂O₃)	$ - 124436 + 36.9T$	<0
10	10[Al] + 3(Ti₃O₅) = 9[Ti] + 5(Al₂O₃)	$ - 802092 + 258.3T$	<0
11	4[Al] + 3(Al₂TiO₅) = 3[Ti] + 5(Al₂O₃)	$ - 1903721 + 765.2T$	<0
12	4[Al] + (Ti₂O₃) + 7[O] = 2(Al₂TiO₅)	$ - 1713221 + 455.2T$	>0
13	6[Al] + (Ti₃O₅) + 10[O] = 3(Al₂TiO₅)	$ - 2446403 + 632.9T$	>0

下載: 導出CSV

表 5 1600 °C下的活度相互作用系數^[26-27]

Table 5. Activity interaction parameters of elements in the steel at 1600 ℃^[26-27]

$ e_i^j $ (j→)	C	Si	Mn	S	Al	Ti	O
Al	0.091	0.056	—	0.035	0.043	0.016	?1.98
Ti	?0.165	0.05	?0.043	?0.27	0.024	0.013	?1.8
O	?0.45	?0.066	?0.021	?0.133	?1.17	?0.6	?0.17

下載: 導出CSV

259luxu-164

參考文獻(27)

[1]	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 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
[2]	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 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
[3]	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 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
[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]	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 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
[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]	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 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
[8]	Wang Q M, Cheng G G. Metallurgy development of Ti-stabilized stainless steel. Chin J Eng, 2021, 43(11): 1447 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
[9]	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
[10]	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 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
[11]	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 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
[12]	Zhang L F. Non-metallic Inclusions in Steels: Industrial Practice. Beijing: Metallurgical Industry Press, 2020 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
[13]	Zhang L F. Non-metallic Inclusions in Steels: Fundamentals. Beijing: Metallurgical Industry Press, 2019 張立峰. 鋼中非金屬夾雜物: 基礎. 北京: 冶金工業出版社, 2019
[14]	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 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
[15]	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 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
[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]	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 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
[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]	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
[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]	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 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
[24]	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 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
[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]	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 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