Inclusion characteristic and microstructure of rare earth (RE) elements containing steel were evaluated with scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), element-mapping, optical microscopy (OM), and automated feature analysis (AFA) option equipped with ASPEX PSEM. Factsage was used to calculate the equilibrium inclusion composition. Based on the calculation, an inclusion evolution mechanism was proposed. Furthermore, line scanning analysis was used to elucidate the intra-granular acicular ferrite (IAF) nucleation mechanism. The result showed that two different inclusions exist in sample steel: (Mn-Al-Si-Ti-La-Ce-O) +MnS complex inclusion and isolated MnS inclusion. Almost all nucleation sites for IAF are complex inclusions, while single MnS inclusion cannot induce IAF. A possible formation mechanism of complex inclusion is proposed based on calculated results using Factsage, which agrees well with experimental results. A Mn-depletion zone (MDZ) which exists adjacent to the (Mn-Al-Si-Ti-La-Ce-O) +MnS complex inclusion can account for the IAF formation. However, the low volume fraction (1.49~10- 7) of effective inclusion may result in only 10% (volume fraction) IAF.
参考文献
| [1] | |
| [2] | Y.E. Smith, A.P. Coldren and R.L.Cryderman, Climax Molybdenum Company Ltd (Tokyo, 1972) p.119[2] B.L. Bramfitt, Metall Trans 1(7) (1970) 1987[3] M. Wakoh, T. Sawai and S. Mizoguchi, Tetsu-to-Hagane 78 (11) (1992) 73 [4] J.M. Gregg and H.K.D.H. Bhadeshia, Acta Mater 45(2) (1997) 739[5] C. Eijk, O. Grong and J. Walmsley, Mater Sci Technol 16(1) (2000) 55 [6] Z.Y. Hu, C.W. Yang, M. Jiang,G.W. Yang, W.J. Wang and X.H. Wang, Acta Metall Sin 47(8) (2011) 971 (in Chinese) [7] D. Brooksbank and K.W.Andrews, J Iron Steel Inst 210(4) (1972) 247 [8] D.S. Sarma, A.V. Karasev and P.G. Jonsson, ISIJ Int 49(7) (2009) 1063 [9] G. Thewlis, Mater Sci Technol 22(2) (2006) 153 [10] X.X. Deng, X.H. Wang, M. Jiang, Z.Y.Hu, X.J. Shao and W.J. Wang, J Univ Sci Technol Beijing (2012) in Press [11] G.F. Vander Voort, Metallography,Principles and Practice (McGraw-Hill, New York, 1984) p.427[12] H.S. Kim, H.G. Lee and K.S. Oh, ISIJ Int 42(12) (2002) 1404 [13] H. Goto, K. Miyazawa, K. Yamaguchi, S.Ogibayashi and K. Tanaka, ISIJ Int 34(5) (1994) 414[14] Y. Oh, S. Lee, J. Byun, J. Shim and Y. Cho, Mater Trans JIM 41(12) (2000) 1663 [15] R.T. Dehoff and R.N. Rhines, Quantitative Microscopy (McGraw-Hill, New York,1968) p.168 [16] M. Wakoh, T. Sawai and S. Mizoguchi, Tetsu-to-Hagané |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%