本論文研究成份為鐵-30.1錳-0.64碳(wt%)的合金鋼經時效處理後的相變化情形。合金的前處理為1100℃的固溶處理，而後再於900至400℃的溫度區間進行低溫時效處理。
若時效溫度低於800℃以下時，於沃斯田體晶粒內有共存的M3C及M23C6等二種不同的碳化物。當時效溫度介於800至600℃之間時，可觀察到此二種碳化物各別於沃斯田體晶粒內形成層狀組織，此應為於固溶狀態下的過飽和的沃斯田體晶粒分解為較穩定的低溫沃斯田體晶粒及碳化物。於金相觀察此層狀組織，推斷此層狀組織是於沃斯田體基地的晶界處成核，而後往沃斯田體晶粒內成長。當時效處理溫度低於600℃以下時，發現到此二種碳化物分別與肥粒體晶粒形成的波來體的層狀組織，此為共析反應下沃斯田體晶粒分解為肥粒體與碳化物的共析波來體。值得一提的是當時效溫度低於525℃時，於沃斯田體晶粒內同時有針狀的M3C碳化物魏德曼組織出現。
沃斯田體與M3C碳化物晶粒間有下列方位關係存在，其為[011]γ//[100]c，(1 1)γ//(03 )c；或為[011]γ//[110]c，(11 )γ//(2 0)c。於波來體層狀組織中，觀察到肥粒體晶粒與碳化物有下列方位關的存在：[113]α//[110]c，(1 0)α//(031)c；[113]α//[111]c，(1 0)α//(2 0)c；或為[111]α//[113]C，(0 1)α//(2 0)C，(1 0)α//(03 )C。於魏德曼組織M3C碳化物與沃斯田體晶粒有下列的方位關係存在：其為[011]C//[001]γ，(03 )C//(2 0)γ，(300)C//(220)；或為[021]C//[122]γ，(200)C//(0 2)γ。

We have studied the phase transformations of the steel with a composition of Fe-30.1 Mn-0.64 C (wt%). The steel has undergone the solution heat treatment at 1100℃ and then the aging process at temperatures ranging from 900 to 400℃.
We found the coexistence of the M3C and M23C6 carbides in the austenitic matrix at the aging temperature below 800℃. For the aging temperatures between 800 and 600℃, the coexistence of the M3C and M23C6 carbides is not only in the form of grain boundary precipitates but also in the form of lamellae of carbide and austenite grains. The lamellae structure of the carbide and austenite is due to the decomposition of the austenite phase in its as-quenched condition. For the aging temperatures below 600℃, the coexistence of the M3C and M23C6 carbides is not only in the form of grain boundary precipitates but also in the form of lamellae of carbide and ferrite grains, i.e. in the form of pearlite. The lamellae structure of the carbide and ferrite is due to the decomposition of the austenite phase below the eutectoid temperature. It is worthy to note that Widmanstatten M3C carbide formed in the austenitic matrix at the aging temperature below 525℃.
We found several orientation relationships between the grains of the lamellae. For the prcipitation of the M3C carbide in the austenitic matrix we found the following orientation relationships between the autenitic matrix and the M3C carbide: [011]γ//[100]c, (1 1)γ//(03 )c; and [011]γ//[110]c, (11 )γ//(2 0)c. In the pearlite, the oreination relationships between the ferrite and M3C carbide are as follows: [113]α//[110]c, (1 0)α//(031)c; [113]α//[111]c, (1 0)α//(2 0)c; and [111]α//[113]C, (0 1)α//(2 0)C, (1 0)α//(03 )C. For the precipitation of the Widmanstatten M3C carbide, the followings are orientation relationships between the M3C carbide and the austenitic grains: [011]C//[001]γ, (03 )C//(2 0)γ, (300)C//(220); and [021]C//[122]γ, (200)C//(0 2)γ.

1. D.A. Porter and K.E. Easterling, Phase Transformations in Metals and Alloys, 2/e, 2001.
2. C.R. Hutchinson, G.J. Shiflet, Scripta Materialia., 50, pp.1-5(2004).
3. C.R. Hutchinson, R.E. Hackenberg, G. J. Shiflet, Acta Mat. 52, 3565 (2004).
4. D.S. Zhou, G.J. Shiflet, Scripta Metallurgica , 27, 1215 (1992).
5. S.A. Hackey and G.J. Shiflet, Acta Metall., 35, 1017 (1987).
6. H.J. Goldschmidt and D.Sc,Interstitial Alloys.
7. H. Baker, “ASM Handbook, Vol 3, Alloy Phase Diagrams” (1992).
8. P. R. HOWELL, J. V. BEE, K. and R.W.K. Honeycombe, Metal Science., 8, PP. 1213-1221 (1979).
9. J.B Lupton,S. Murphy, And J.H. Woodhead, Metallurgical Transactions., 3, pp. 2923-2931 (1972).
10. Y.L. Lin and C.P. Chou, Scripta Metall., 27, pp. 67-70 (1992).
11. M. V. KRAL and G. SPANOS, Acta mater. Vol. 47, No. 2, pp. 711-724, 1999.
12. 陳致豪，“鐵-30錳-0.3碳合金鋼之時效相變化研究”，國立台灣科技大學，碩士論文(2008)。
13. 吳旻紘，“鐵-31錳-1.5鋁-0.6碳合金鋼之時效相變化研究”，國立台灣科技大學，碩士論文(2008)。
14. 張育仁，“鐵-30錳-1.7鋁-1碳合金鋼之時效相變化研究”，國立台灣科技大學，碩士論文(2008)。
15. C.R. Hutchinson, R.E. Hackenberg and G.J. Shiflet, Acta Mater., 52, 3565 (2004).
16. 黃振賢，金屬熱處理，文京出版社 第18版 (2000)。
17. W.F. Smith, Structure and Properties of Engineering Alloys, 2/e, 1 (1993).
18. M.H. Lewis, B. Hattersley, Acta Metall., 13,1159 (1965).
19.D.S. Zhou, G.J Shiflet, Scripta Metall. Mater., 27, 1215 (1992).
20 B. Weiss R. Stickler, Metall. Trans., 3, (1972).
21. K.H. Kuo, C.L. Jia, Acta Metall., 33, No.6, 991 (1985).
22. 蔡明欽，鋼顯微組織與性質，五南圖書股份有限公司，(2004)。
23. G. Spanos and H. I. Aaronson, Scripta METALLURGICA. Vol. 22, pp. 1537-1542, (1998)
24. M.-X. ZHANG and P. M. KELLY, Acta mater. Vol. 46, No. 13, pp. 4617-4628, (1998)
25. S. W. Thompson and P. R. Howelt, Scripta METALLURGICA Vol. 21, p p . 1353-1357, (1987)
26. K. H. YANG and W. K. CHOO, Acta metall. Mater., Vol. 42, No. 1, pp. 263-269 (1994).
27. 鮑忠興，“近代穿透式電子顯微鏡實務”，(2008)。
28. 林東一，“鐵-21錳-0.4碳合金鋼之麻田散體相變化研究”，國立台灣科技大學，碩士論文(2007)