为更精确地控制及优化X70管线钢的目标组织，以经典相变理论模型为基础，建立了先共析铁素体周围的临界碳浓度与原奥氏体的碳浓度之间的数学模型，并采用逆向回归法确定了铁素体相变分数的关键性参数，经试验验证，模型具有良好的精度。结果表明：临界碳浓度满足C^k=1．8，关系；铁素体相变分数的关键性参数m=1．3，b1=0．026，b2=-3．2；以冷速5℃js为f临界点，冷速对铁素体相变开始点的影响程度有明显变化；锰和铌含量对于铁素体相变开始温度的影响主要体现在α／γ界面处的溶质拖曳作用，铁素体相变开始温度由冷却速率和原始奥氏体晶界面积的乘积决定。
In order to control and optimize microstructure of X70 pipeline steel more accurately, the mathematical model between critical carbon concentration around proeutectoid ferrite and original carbon concentration of austen ite was regressed based on classical phase transformation theory models. The key parameters of ferrite transformation were obtained by reversed regression method. It was confirmed that the model and the experimental result had a good agreement. It is shown that the critical carbon concentration agrees with a relational expression of c＊=1. 8c^0. The key parameters of ferrite transformation are as follows m=1.3, b1=0. 026, b2 = 3.2; the start tern perature of ferrite transformation has obvious effects on cooling rate when 5 ℃/s as critical point. The solute drag-like effect of α/γ interface is the main influence of composition of Mn and Nb on the start temperature of ferrite transfor mation. The start temperature of ferrite transformation is dominated by cooling rate and the area of austenite grain.
参考文献
| [1] | M.MILITZER;R. PANDI .Ferrite Nucleation and Growth During Continuous Cooling[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,1996(6):1547-1556. |
| [2] | Lee K J;LeeJ K;Kang K B et al.Mathematical Modeling of Transformation in Nb Microalloyed Steels[J].ISIJ International,1992,32(03):326. |
| [3] | 许云波,于永梅,刘相华,王国栋.热变形过程中γ→α相变开始温度的预测--C-Mn钢与Nb-V微合金钢[J].东北大学学报（自然科学版）,2005(01):59-62. |
| [4] | Militzer M;Hawbolt E B;Meadowcroft T R .Microstructure Model for Hot Strip Rolling of High-Strength Low-Alloy Steels[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,2000,31A(04):1247. |
| [5] | Matthias MILITZER .Computer Simulation of Microstructure Evolution in Low Carbon Sheet Steels[J].ISIJ International,2007(1):1-15. |
| [6] | N. NAKATA;M. MILITZER .Modelling of microstructure evolution during hot rolling of a 780 MPa high strength steel[J].ISIJ International,2005(1):82-90. |
| [7] | ZHAO J Z;Mesplont C;Cooman B C D .Kinetics of Phase Transformation in Steels--A New Method for Analysing Dilatometrie Results[J].ISIJ International,2001,41(05):492. |
| [8] | 邓天勇 .基于组织性能预测的柔性化轧制工艺制定方法[D].东北大学,2008. |
| [9] | Jones S J;Bhadeshia H K D H .Kinetics of the Simultaneous Decomposition of Austenite into Several Transformation Products[J].Acta Materialia,1997,45(07):2911. |
| [10] | LIU D S;Militzer M;Poole W J .Microstructure Model for a Dual-Phase Steel[J].Materials Science Forum,2007,539/ 543(03):4391. |
| [11] | DONGSHENG LIU;F. FAZELI;M.MILITZER .A Microstructure Evolution Model for Hot Rolling of a Mo-TRIP Steel[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,2007(4):894-909. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%