Microalloying element Nb in low carbon steels produced by compact strip production (CSP) process plays an important role in inhibiting recrystallization, decreasing the transformation temperature and grain refinement.With decreasing the rolling temperature, dislocations can be pinned by carbonitrides and the strength is increased. Based on the two sublattice model, with metal atom sublattice and interstitial atom sublattice,a thermodynamic model for carbonitride was established to calculate the equilibrium between matrix and carbonitride. In the steel produced by CSP, the calculation results showed that the starting temperature of precipitation of Ti and Nb are 1340℃ and 1040℃, respectively. In the range of 890-950℃, Nb rapidly precipitated. And the maximum of the atomic fraction of Nb in carbonitride was about 0.68. The morphologies and energy spectrum of the precipitates showed that (NbTi) (CN) precipitated near the dislocations. The experiment results show that Nb rapidly precipitated when the temperature was lower than 970℃, and the atomic fraction of Nb in carbonitride was about 60%-80%. The calculation results are in agreement with the experiment data. Therefore the thermodynamic model can be a useful assistant tool in the research on the precipitates in the low carbon steels produced by CSP.
参考文献
| [1] | P B Hendel;M McDonald .[J].IRON AND STEEL ENGINEER,1993,70(12):36. |
| [2] | Y L Kang;H Yu;J Fu;K L Wang Z B Wang .[J].Materials Science and Engineering,2003,A351:265. |
| [3] | Jueding SUN;Shixue DING .[J].J Iron Steel Res,2005,144(03):53. |
| [4] | Ziquan LIN;Liege AO;Sen HAO .Iron Steel Vanadium Titanium[J].,2001,3(01) |
| [5] | M T Nagata;J G Speer;D K Matlock .[J].Metallurgical and Materials Transactions,2002,33A:3099. |
| [6] | N Fujita .[D].剑桥大学,2000. |
| [7] | CITIC Microalloy Technology Center.Niobium Science and Techmology[M].北京:冶金工业出版社,2003 |
| [8] | H Adrian .[J].Materials Science and Technology,1992,8(05):406. |
| [9] | J G Speer;J R Michael;S S Hansen .[J].METALLURGICAL TRANSACTIONS,1987,1SA:211. |
| [10] | W J LIU;J J Jonas .[J].METALLURGICAL TRANSACTIONS,1989,20A:1361. |
| [11] | S Suzuki;G C Weatherly;D C Houghton .[J].Acta Metalluraica,1987,35:341. |
| [12] | Shiming HAO.Material Thermodynamic[M].北京:化学工业出版社,2004 |
| [13] | P R Rios .[J].MATERIAL SCIENCE AND ENGINEERING,1991,A142:87. |
| [14] | P R Rios .[J].MATERIAL SCIENCE AND ENGINEERING,1992,A156:L5. |
| [15] | K.Inoue .Solubility Product of TiN in Austenite[J].ISIJ International,1998(9):991-997. |
| [16] | D F Griffiths;G A Watson.Numerical Analysis[M].Longman Scientific & Technical,Essex,1986 |
| [17] | A S Householder.Principles of Numerical Analysis[M].New York:McGraw-Hill,Inc,1953:135. |
| [18] | R L Burden;J D Faires.Numerical Analysis[M].北京:高等教育出版社,2001:66. |
| [19] | Y Li;Y Z Liu;J Z He;L B Liu D Y Chang.[A].北京:冶金工业出版社,2005:810. |
| [20] | Shujun JIAO .[D].北京:北京科技大学,1997. |
| [21] | Shaoqiang YUAN .[D].北京:北京科技大学,2004. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%