臺灣博碩士論文加值系統

眾多的鋼鐵材料中都會添加一些合金元素來達到所要求的強度、韌性等機械性質。其中矽與鋁為常見的合金元素，皆為肥粒鐵相穩定元素。本實驗中仍有鈦與鉬在肥粒鐵相基地析出奈米碳化物以進行界面析出強化。因此，本研究目的在於探討添加矽與鋁在界面析出強化鋼材中所產生的交互作用。
除了改變合金元素外，藉由不同的熱處理，鋼材也可以有不同的特性。隨著兩相持溫溫度的降低，晶粒尺寸下降且硬度上升；隨著沃斯田鐵化溫度的提高，普遍晶粒尺寸皆上升但硬度仍然提高。藉由穿透式電子顯微鏡的觀察，在較高的沃斯田鐵化溫度，具有密集的界面析出碳化物。此界面析出碳化物的變化透過換算而得之貢獻強度也因變密集而上升，使鋼材更為堅固。
取代部分矽為鋁添加於鋼鐵材料中，也造成不同的效果。鋁對於肥粒鐵的生長具有明顯的加速作用，不僅透過金相可以觀察此特性之外，也反映在相變曲線上。有添加鋁的鋼鐵材料會使相變曲線往左移動，使整體相變態反應提早。而矽的添加對於肥粒鐵相的固溶強化有顯著的影響，且可以使肥粒鐵相區擴大，但在高溫時傾向析出大尺寸的碳化物，影響界面析出強化機制之削弱。

In steel, it will be added some alloy elements to improve its strength, toughness. mechanical properties. Silicon and Aluminum are the common alloy elements in it. They both are ferrite stabilizer elements. In this study, there are titanium and molybdenum which precipitate nanometer carbides to interphase-precipitated strengthen in materials. Consequently, the goal of this study is to discuss the interaction of interphase precipitation strengthened steels with the addition of silicon and aluminum.
Through the different heat treatment, we also can observe different characteristics of steel. By dual-phase holding temperature lowing, the grain size becomes small and harder; by increasing austenitization temperature, grain size generally increases but the values of hardness also increases. Through transmission electron microscope, there are intense interphase-precipitated carbides in steel at the higher austenitization temperature, and it contributes more strength to steel, becomes stronger.
Replacing some silicon by aluminum can give rise to different effect. The aluminum can accelerate the growth of the ferrite. It is not only can be observed by optical microscope but also in TTT curve. The TTT curve will move to the left when adding aluminum to steel. The aluminum can make the whole phase transformation earlier. On the other hand, the silicon has an outstanding influence of solid solution strengthening and makes the phase region of ferrite bigger. However, it tends to precipitate big size carbides at high temperature and to weaken the mechanism of interphase precipitation strengthening.

口試委員會審定書 #
致謝 i
摘要 ii
ABSTRACT iii
CONTENTS iv
LIST OF FIGURES vii
LIST OF TABLES x
Chapter 1 研究背景 1
Chapter 2 文獻回顧 2
2.1 相變態反應 2
2.1.1 肥粒鐵 5
2.1.2 麻田散鐵 6
2.2 強化機制 8
2.2.1 固溶強化 9
2.2.2 細晶強化 11
2.2.3 加工硬化 12
2.2.4 第二相強化 13
2.2.5 析出硬化 14
2.3 界面析出機制 16
2.3.1 平整界面析出 17
2.3.2 曲面界面析出 18
2.4 合金元素對鋼鐵性質的影響 20
2.4.1 矽 21
2.4.2 鋁 22
2.4.3 鈦 23
2.4.4 鉬 23
Chapter 3 實驗設計與步驟 25
3.1 實驗材料與試片準備 25
3.2 實驗步驟及使用儀器 26
3.2.1 熱處理設計 27
3.2.2 金相 29
3.2.3 微硬度測試 29
3.2.4 穿透式電子顯微鏡試片製作與觀察 30
Chapter 4 實驗結果與討論 31
4.1 同成份不同兩相持溫溫度鋼材之討論 31
4.1.1 同成份不同兩相持溫溫度鋼材金相圖比較 32
4.1.2 同成份不同兩相持溫溫度鋼材硬度值比較 36
4.1.3 同成份不同兩相持溫溫度鋼材之TEM觀察 38
4.2 不同成份鋼材之討論 41
4.2.1 不同成份鋼材金相圖比較 42
4.2.2 不同成份鋼材硬度值比較 46
4.2.3 不同成份鋼材之TEM觀察 49
4.3 同成份不同沃斯田鐵化溫度鋼材之討論 54
4.3.1 同成份不同沃斯田鐵化溫度鋼材金相圖比較 55
4.3.2 同成份不同沃斯田鐵化溫度鋼材硬度值比較 60
4.3.3 同成份不同沃斯田鐵化溫度鋼材之TEM觀察 63
4.4 相變曲線TTT Diagram 72
Chapter 5 結論 78
同成份不同兩相持溫溫度鋼材之討論： 78
不同成份鋼材之討論： 78
同成份不同沃斯田鐵化溫度鋼材之討論： 78
相變曲線TTT Diagram： 78
REFERENCE 79

1. Leslie, W.C., The physical metallurgy of steels. 1981.

2. Honeycombe, R.W.K. and R.F. Mehl, Transformation from austenite in alloy steels. Metallurgical Transactions A, 1976. 7(7): p. 915-936.

3. Davenport, A.T.a.R.W.K.H., Proceedings of the Royal Society of London Series a-Mathematical and Physical Sciences, 1971(322(1549)): p. 191.

4. Lagneborg, R., et al., Scandinavian Journal of Metallurgy. 1999(28(5)): p. 186.

5. Lagneborg, R.a.S.Z., Metallurgical and Materials Transactions a-Physical
Metallurgy and Materials Science, 2001(32(1)): p. 39.

6. Zajac, S., Precipitation of microalloy carbo-nitrides prior, during and after
gamma/alpha transformation. 2005.

7. Shimizu, T., Y. Funakaw, and S. Kaneko, JFE TECHNICAL REPORT. 2004. p. 25.

8. Funakawa, Y., et al., Isij International, 2004(44(11)): p. 1945.

9. Bhadeshia, H.K.D.H.a.R.W.K.H., Steels. microstructure and properties. 2006.

10. Babu, S.S. and H.K.D.H. Bhadeshia, A direct study of grain boundary allotriomorphic ferrite crystallography. Materials Science and Engineering: A, 1991. 142(2): p. 209-219.

11. Hung-Wei Yen, C.-Y.H.a.J.-R.Y., Scripta Materialia, 2009(61).

12. Bain, E.C. and N. Dunkirk, The nature of martensite. trans. AIME, 1924. 70(1): p. 25-47.

13. Greninger, A.B.a.A.R.T., Transactions of the American Institute of Mining and Metallurgical Engineers, 1949. 185(9): p. 590.

14. H. W. Yen, P.Y.C., C. Y. Huang, J. R. Yang, Acta Materialia, 2011. 59.

15. Gladman, T., The Physical Metallurgy of Microalloyed Steels. The Institute of Materials., 1997.

16. D.K. Felbeck, A.G.A., Strength and fracture of engineering solids. Prentice-Hall, Eaglewood Cliffs, NJ,, 1984.

17. Pickering, F.B., Physical metallurgical and the design of steel (Applied science,London, 1978.

18. Bergstrom, Y.a.H.H., Metal Science, 1983. 17(7): p. 341.

19. Hall, E.O., Proceedings of the Physical Society of London Section B, 1951. 64(381): p. 747.

20. Petch, N.J., Journal of the Iron and Steel Institute, 1953. 174(1): p. 25.

21. F.M. Al-Abbasi, J.A., International Journal of Mechanical Sciences, 2003. 45.

22. C.Y. Huang, H.W.Y., Y. T. Pan, J.R. Yang, CIMME, 2009. 53(4).

23. Gladman, T., Materials Science and Technology, 1999. 15: p. 30.

24. Hull, D. and D.J. Bacon, 7 - Jogs and the Intersection of Dislocations, in Introduction to Dislocations (Fourth Edition). 2001, Butterworth-Heinemann: Oxford. p. 128-144.

25. Honeycombe, R.W.K., 29th HATFIELD MEMORIAL LECTURE: Ferrite. Metal Science, 1980. 14(6): p. 201-214.

26. Li, P.a.J.T., Metallurgical and Materials Transactions A, 1988. 19(9): p. 2139.

27. Ricks, R.A. and P.R. Howell, The formation of discrete precipitate dispersions on mobile interphase boundaries in iron-base alloys. Acta Metallurgica, 1983. 31(6): p. 853-861.

28. Ricks, R.A.a.P.R.H., Metal Science, 1982. 16(6): p. 317.

29. Bhadeshia, H.K.D.H., Bainite in steels. transformations, microstructure and
properties /. 2001.

30. Aaronson, M.E.a.H.I., Metall. Trans., 1986(17): p. 1385.

31. Lee, S.H.L.a.K.J., Adv. Mater. Res., 2007(26-28): p. 1307.

32. M. H. Cai, H.D., J. S. Zhang and L. Li, Acta Metall. Sin. (Engl. Lett.), 2009(22): p. 100.

33. C. Ouchi, T.S.a.I.K., Trans., Isij International, 1982: p. 214.

34. Dong, J.X., et al., Effect of silicon on the kinetics of Nb(C, N) precipitation during the hot working of Nb-bearing steels. Isij International, 2000. 40(6): p. 613-618.

35. Han, K., G.D.W. Smith, and D.V. Edmonds, Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science, 1995. 26(7): p. 1617.

36. Heller, T. and A. Nuss, Effect of alloying elements on microstructure and mechanical properties of hot rolled multiphase steels. Ironmaking & Steelmaking, 2005. 32(4): p. 303-308.

37. Evans, P., The influence of rolling and forging on product quality and properties. Session 3, Paper 1. SMEA Conf. on, 2008.

38. Girault, E., et al., Comparison of the effects of silicon and aluminium on the tensile behaviour of multiphase TRIP-assisted steels. Scripta materialia, 2001. 44(6): p. 885-892.

39. Tsai, S.-P., et al., Effect of Cr and Al additions on the development of interphase-precipitated carbides strengthened dual-phase Ti-bearing steels. Materials & Design, 2017. 119: p. 319-325.

40. Mein, A., et al., The influence of aluminium on the ferrite formation and microstructural development in hot rolled dual-phase steel. Materials Characterization, 2012. 64: p. 69-78.

41. Totten, G.E., Steel heat treatment : metallurgy and technologies. 2 ed.CRCNetBASE. 2007, Boca Raton, FL : Taylor & Francis.

42. Mohrbacher, H., Principal effects of Mo in HSLA steels and cross effects with microalloying elements. Central Iron and Steel Research Institute (CISRI), 2010: p. 75-96.

43. A.D. Batte, R.W.K.H., Metal Sci J, 1973: p. 160.
44. Kocks, U.F., On the spacing of dispersed obstacles. Acta Metallurgica, 1966. 14(11): p. 1629-1631.