Thermodynamic Simulation of Carbonitride Precipitation in Micro-alloyed Steel

doi:10.16182/j.issn1004731x.joss.17-0147

Abstract

Abstract: A mathematical model for calculating the precipitation of carbonitride in the process of hot rolling of composite micro-alloyed steel is established, and the interaction between the carbonitride and AlN is considered. In view of the difficulties of the thermodynamic model that the variables are multiple, the equations are nonlinear and the boundary conditions are determined difficultly, the Newton-Raphson numerical algorithm characterized by coupled problem is adopted. The precipitation starting temperature and precipitation sequence of carbonitride and AlN at different compositions are determined. The equilibrium composition of elements in austenite, the composition and mass fraction of carbonitride precipitates, as well as other variation laws with the rolling temperature are obtained. The simulation and analysis are carried out based on the actual production data of a steel plant. The results show that the model is basically in accordance with the relevant metallurgical mechanism, which has an important guiding significance for the effective control of the microstructure and properties of steel.

Key words: hot rolling, micro-alloyed steel, carbonitride, precipitation, thermodynamic model

CLC Number:

TP391.9

Li Weigang, Yang Wei, Liu Chao, Yan Baokang. Thermodynamic Simulation of Carbonitride Precipitation in Micro-alloyed Steel[J]. Journal of System Simulation, 2019, 31(3): 520-527.

References

[1] 唐广波, 吴秀月, 雍兮, 等. 复合微合金化高强度低合金钢奥氏体相中碳氮化物析出热力学数值模拟[J]. 金属热处理, 2008, 33(8): 67-72.
Tang G B, Wu X Y, Yong X, et al.Numerical simulation of thermodynamic for carbonitride precipitation in austenite of complex microalloyed high strength and low alloy steels[J]. Heat treatment of metals, 2008, 33(8): 67-72.
[2] 吴秀月. 微合金元素在热连轧过程中的溶解析出数值模拟研究[D]. 昆明: 昆明理工大学, 2009.
Wu X Y.Numerical simulation of solid solution and precipitation of micro-alloying elements during hot rolling process[D]. Kunming: Kunming University of Science and Technology, 2009.
[3] 李远远. Nb-Ti低碳微合金钢的组织及析出控制研究[D]. 沈阳: 东北大学, 2013.
Li Y Y.Research of Microstructure and precipitate control in Nb-Ti micro-alloyed low-carbon steel[D]. Shenyang: Northeastern University, 2013.
[4] 王蕾, 唐荻, 宋勇. 热轧带钢组织性能预报模型及应用[J]. 钢铁, 2016, 51(11): 73-78.
Wang L, Tang D, Song Y.Prediction model for microstructures and properties on hot strip rolling[J]. Iron and Steel, 2016, 51(11): 73-78.
[5] Wang Y L, Zhuo L C, Chen M W, et al.Thermodynamic model for precipitation of carbonitrides in microalloyed steels and its application in Ti-V-C-N system[J]. Rare Metals (S1001-0521), 2016, 35(10): 735-741.
[6] 彭宁琦, 唐广波, 刘正东, 等. 热连轧过程复合微合金碳氮化物析出的定量计算[J]. 材料热处理学报, 2011, 32(6): 155-161.
Peng N Q, Tang G B, Liu Z D, et al.Quantitative calculation on precipitation behavior of complex microalloyed carbonitride during hot rolling[J]. Transactions of Materials and Heat Treatment, 2011, 32(6): 155-161.
[7] 解家英, 张利君, 王凤琴. 高Ti-Q550钢中Nb、Ti第二相的析出行为[J]. 钢铁研究学报, 2013, 25(3): 54-58.
Xie J Y, Zhang L J, Wang F Q.Precipitation behaviour of Nb, Ti second phase in high Ti-Q550 steel[J]. Journal of Iron and Steel Research, 2013, 25(3): 54-58.
[8] Gorbachev I I, Popov V V, Pasynkov A Y.Thermodynamic modeling of carbonitride formation in steels with V and Ti[J]. The Physics of Metals and Metallography (S0031-918X), 2012, 113(10): 974-981.
[9] 许云波, 于永梅, 吴迪, 等. Nb微合金钢析出行为的热力学计算[J]. 材料研究学报, 2006, 20(1): 104-108.
Xu Y B, Yu Y M, Wu D, et al.Thermodynamic calculations of precipitation behavior in Nb microalloyed steels[J]. Chinese journal of materials research, 2006, 20(1): 104-108.
[10] Adrian H.Thermodynamic model for precipitation of carbonitrides in high strength low alloy steels containing up to three microalloying elements with or without additions of aluminium[J]. Materials Science and Technology (S0267-0836), 1992, 8(5): 406-420.
[11] 吴志桥, 高普云, 任钧国. Runge-Kutta方法求解结构动力学方程[J]. 系统仿真学报, 2010, 22(9): 2085-2090.
Wu Z Q, Gao P Y, Ren J G.Runge-Kutta methods for time integration in structural dynamics[J]. Journal of system simulation, 2010, 22(9): 2085-2090.
[12] 李维刚, 胡石雄, 刘斌, 等. 热轧含Nb微合金钢力学性能预报模型研究[J]. 冶金自动化, 2017, 41(2): 15-21.
Li W G, Hu S X, Liu B, et al.Prediction model of mechanical properties of hot-rolled high strength Nb micro-alloyed steel[J]. Metallurgical Industry Automation, 2017, 41(2): 15-21.