Abstract
TiN, which is ubiquitous in Ti-bearing steel, has a critical influence on both the mechanical properties and the welding process of steel, and therefore researche on the precipitation behavior of TiN in molten steel bath is of great significance. In this paper, Ti-bearing peritectic steel was taken as the study object and FactSage was adopted to explore how the precipitation behavior of typical inclusions in steel was affected by the steel composition. Furthermore, microsegregation models were used to analyze the precipitation process of TiN at solidification front, and the calculation results were finally verified by scanning electron microscope (SEM). Research showed that a multitude of dispersed particles of high melting oxide MgAl2O4 or MgO always existed in molten steel after magnesium treatment. In consideration of the segregation and enrichment of solute elements at the solidification front, the Ohnaka microsegregation model was employed to compute the precipitation during solidification. In the event of the solid fraction reaching 0.95 or more, the concentration product of [Ti][N] at the solidification front exceeded the equilibrium concentration product, then TiN began to precipitate. MgO or MgAl2O4 cores were generally found in TiN particles of peritectic steel after the magnesium treatment, which was consistent with the thermodynamic calculation results. Moreover, the average size of TiN particles was reduced by approximately 49%. This demonstrated that Mg-rich high melting inclusions were formed after the magnesium treatment, by which the heterogeneous nucleation of TiN was promoted it; therefore, favorable nucleation sites were provided for further refining the high-temperature ferrite phase.
摘要
含 Ti 钢中普遍存在的 TiN 对钢的力学性能和焊接过程有重要影响, 研究 TiN 在冶金熔池中的析出行为有重要意义. 本文以含 Ti 包晶钢为研究对象, 采用 FactSage 计算了钢种成分对钢中典型夹杂物析出行为的影响规律. 采用微观偏析模型对凝固前沿 TiN 的析出过程进行了分析, 借助 SEM 对计算结果进行了验证. 研究结果表明, 镁处理后钢液中始终存在大量弥散分布的高熔点氧化物 MgAl2O4 或 MgO, 考虑溶质元素在凝固前沿的偏聚富集现象, 利用 Ohnaka 微观偏析模型进行凝固析出计算, 当固相率达到 0.95 时凝固前沿的[Ti][N]浓度积高于平衡浓度积, 开始析出 TiN. 镁处理后包晶钢中 TiN 颗粒内部普遍存在 MgO 或 MgAl2O4 核心, 与热力学计算结果相符, 且 TiN 颗粒平均尺寸减小了 62%左右, 表明镁处理形成富镁高熔点夹杂物促使了 TiN 异质形核, 为进一步细化高温铁素体相提供了有利的形核质点.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
TAKAHASHI T, OHSASA K, TANAKA J. Peritectic reaction and S-y transformation mechanism in carbon steels [J]. Tetsu-to-Hagane, 1987, 73(1): 99–106. DOI: https://doi.org/10.2355/tetsutohagane1955.73.1_99. (in Japanese)
MARUYAMA T, MATSUURA K, KUDOH M, ITOH Y. Peritectic transformation and austenite grain formation for hyper-peritectic carbon steel [J]. Tetsu-to-Hagane, 1999, 85(8): 585–591. DOI: https://doi.org/10.2355/tetsutohagane1955.85.8_585. (in Japanese)
KUDOH M, IGARASHI K, MATSUURA K, OHSASA K. Peritectic transformation in low carbon steels containing high phosphorus concentration [J]. ISIJ International, 2008, 48(3): 334–339. DOI: https://doi.org/10.2355/isijinternational.48.334.
CHEN Hua-biao, LONG Mu-jun, CAO Jun-sheng, CHEN Deng-fu, LIU Tao, DONG Zhi-hua. Phase transition of peritectic steel Q345 and its effect on the equilibrium partition coefficients of solutes [J]. Metals, 2017, 7(8): 288. DOI: https://doi.org/10.3390/met7080288.
GUO Jun-li, WEN Guang-hua, TANG Ping, FU Jiao-jiao, GU Shao-peng. Analysis of crack susceptibility of peritectic steels based on surface roughness [J]. Steel Research International, 2020, 91(2):1900376. DOI: https://doi.org/10.1002/srin.201900376.
ALFARO L E, HERRERA T M, RUÍZ M J J, de JESÚS C R M, SOLÍS T H. Effect of C and Mn variations upon the solidification mode and surface cracking susceptibility of peritectic steels [J]. ISIJ International, 2009, 49(6): 851–858. DOI: https://doi.org/10.2355/isijinternational.49.851.
KOROJY B, NASSAR H, FREDRIKSSON H. Hot crack formation during peritectic reaction in steels [J]. Ironmaking & Steelmaking, 2010, 37(1): 63–72. DOI: https://doi.org/10.1179/030192309X12506804200429.
TREJO M H, LOPEZ E A, RUIZ M J J, CASTRO R M D J, TOVAR H S. Effect of solidification path and contraction on the cracking susceptibility of carbon peritectic steels [J]. Metals and Materials International, 2010, 16(5): 731–737. DOI: https://doi.org/10.1007/s12540-010-1006-7.
SALEEM S, VYNNYCKY M, FREDRIKSSON H. The influence of peritectic reaction/transformation on crack susceptibility in the continuous casting of steels [J]. Metallurgical and Materials Transactions B, 2017, 48(3): 1625–1635. DOI: https://doi.org/10.1007/s11663-017-0926-8.
SUZUKI M, HAYASHI H, SHIBATA H, EMI T, LEE I J. Simulation of transverse crack formation on continuously cast peritectic medium carbon steel slabs [J]. Steel Research, 1999, 70(10): 412–419. DOI: https://doi.org/10.1002/srin.199905660.
BRAMFITT B L. The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron [J]. Metallurgical Transactions, 1970, 1(7): 1987–1995. DOI: https://doi.org/10.1007/BF02642799.
BAKER T N. Microalloyed steels [J]. Ironmaking & Steelmaking, 2016, 43(4): 264–307. DOI: https://doi.org/10.1179/1743281215Y.0000000063.
MORIKAGE Y, OI K, KAWABATA F, AMANO K. Effect of TiN size on ferrite nucleation on TiN in low-C steel [J]. Tetsu-to-Hagane, 1998, 84(7): 510–515. DOI: https://doi.org/10.2355/tetsutohagane1955.84.7_510.
SARMA D S, KARASEV A V, JÖNSSON P G. On the role of non-metallic inclusions in the nucleation of acicular ferrite in steels [J]. ISIJ International, 2009, 49(7): 1063–1074. DOI: https://doi.org/10.2355/isijinternational.49.1063.
KIMURA K, FUKUMOTO S, SHIGESATO G I, TAKAHASHI A. Effect of Mg addition on equiaxed grain formation in ferritic stainless steel [J]. ISIJ International, 2013, 53(12): 2167–2175. DOI: https://doi.org/10.2355/isijinternational.53.2167.
FUKUMOTO S, KIMURA K, TAKAHASHI A. Formation of fine macrostructure in ferritic stainless steel [J]. Tetsu-to-Hagane, 2012, 98(7): 351–357. DOI: https://doi.org/10.2355/tetsutohagane.98.351. (in Japanese)
PARK J S, KIM D H, PARK J H. TEM characterization of a TiN-MgAl2O4 epitaxial interface [J]. Journal of Alloys and Compounds, 2017, 695: 476–481. DOI: https://doi.org/10.1016/j.jallcom.2016.11.103
KIM J Y, OH N R, OH Y H, CHO Y T, LEE W B, KIM S K, HONG H U. Hetero-epitaxial nucleation of ferrite at a TiN encapsulating MgAl2O4 during rapid solidification in a newly developed ferritic stainless steel [J]. Materials Characterization, 2017, 132: 348–353. https://doi.org/10.1016/j.matchar.2017.09.001.
ZHANG C W, QU T P, WANG D Y, et al. Effect of magnesium and titanium composite treatment on solidification structure of stainless steel and its mechanism [J]. Journal of Iron and Steel Research, 2019, 31(7): 661–667. DOI: https://doi.org/10.13228/j.boyuan.issn1001.0963-20180310.
WON Y M, THOMAS B G. Simple model of microsegregation during solidification of steels [J]. Metallurgical and Materials Transactions A, 2001, 32(7): 1755–1767. DOI: https://doi.org/10.1007/s11661-001-0152-4.
OHNAKA I. Mathematical analysis of solute redistribution during solidification with diffusion in solid phase [J]. Transactions of the Iron and Steel Institute of Japan, 1986, 26(12): 1045–1051. DOI: https://doi.org/10.2355/isijinternational1966.26.1045.
CLYNE T W, KURZ W. Solute redistribution during solidification with rapid solid state diffusion [J]. Metallurgical Transactions A, 1981, 12(6): 965–971. DOI: https://doi.org/10.1007/BF02643477.
CLYNE T W, WOLF M, KURZ W. The effect of melt composition on solidification cracking of steel, with particular reference to continuous casting [J]. Metallurgical Transactions B, 1982, 13(2): 259–266. DOI: https://doi.org/10.1007/BF02664583.
VOLLER V R, BECKERMANN C. Approximate models of microsegregation with coarsening [J]. Metallurgical and Materials Transactions A, 1999, 30(11): 3016–3019. DOI: https://doi.org/10.1007/s11661-999-0141-6.
WON Y M, KIM K H, YEO T J, OH K H. Effect of cooling rate on ZST, LIT and ZDT of carbon steels near melting point [J]. ISIJ International, 1998, 38(10): 1093–1099. DOI: https://doi.org/10.2355/isijinternational.38.1093.
CHOUDHARY S K, GHOSH A. Mathematical model for prediction of composition of inclusions formed during solidification of liquid steel [J]. ISIJ International, 2009, 49(12): 1819–1827. DOI: https://doi.org/10.2355/isijinternational.49.1819.
Author information
Authors and Affiliations
Contributions
QU Tian-peng and WANG De-yong designed the experiment and the thermal calculation cases. WANG Hui-hua and TIAN Jun analyzed the measured data. The initial draft of the manuscript was written by QU Tian-peng and HOU Dong. All authors replied to reviewers’ comments and revised the final version.
Corresponding author
Ethics declarations
QU Tian-peng, WANG De-yong, WANG Hui-hua, HOU Dong and TIAN Jun declare that they have no conflict of interest.
Additional information
Foundation item: Projects(51774208, 52074186, U1860205) supported by the National Natural Science Foundation of China
Rights and permissions
About this article
Cite this article
Qu, Tp., Wang, Dy., Wang, Hh. et al. Thermodynamic analysis on tin precipitation behavior in Ti-bearing peritectic steel after magnesium treatment. J. Cent. South Univ. 27, 3637–3651 (2020). https://doi.org/10.1007/s11771-020-4567-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11771-020-4567-8