本論文研究鐵-20.1錳-0.5碳(wt%)合金的時效相變化情形。此合金於1100°C的高溫時為單一的沃斯田體相。而於冷卻過程中，沃斯田體晶粒內有條狀麻田散體的產生。此麻田散體具有HCP 的結晶結構或是FCC的雙晶。
經溫度為700℃以下時效處理的合金，有共存的M3C及M23C6碳化物於沃斯田體晶界處成核成長。當溫度低於550℃時，此二種碳化物也以波來體組織之形式，各別出現於沃斯田體晶粒內。
本研究觀察到層狀M3C碳化物之波來體組織形成的初始狀態， M3C碳化物先於沃斯田體晶界處成核成長，因其會消耗鄰近沃斯田體的碳含量，所以鄰接碳化物之基地便成了低碳含量區，如此促成了肥粒體晶粒的成核成長；當肥粒體晶粒成核成長，又將其晶粒內之多餘碳排至其晶粒外之沃斯田體基材，如此又促成了M3C碳化物的成核成長。故於波來體組織形成過程中，層狀M3C碳化物與層狀肥粒體晶粒會呈現間隔的排列。
除了層狀M3C碳化物之波來體組織外，我們亦發現了層狀M23C6碳化物之波來體組織。此層狀M23C6碳化物與肥粒體晶粒間存在有K-S方位關係。此種由M23C6碳化物與肥粒體晶粒組成之似波來體組織，為首次於三元之高錳中被發現。

We studied the phase transformations of a high manganese steel in the aging process. The composition of the steel is Fe-20.1 Mn-0.5 C (wt%). The alloy is a single phase of FCC at high temperature 1100℃. The wicker-shape precipitates in the FCC matrix are martensites which identified as either HCP or FCC twins.
When the aging temperature was below 700℃, we observed two kinds of carbides coexist along FCC grain boundaries. One is M23C6 and the other M3C carbide. When the aging temperature was below 550℃, two kinds of pearlites with either M3C or M23C6 carbides both appeared within FCC grains.
We observed the initial stage of the growing pearlite composing layer structure of M3C carbide and ferrite. M3C carbide first nucleated and grew along FCC grain boundaries. The carbon content of the FCC matrix near the M3C carbide was depleted. This situation causes the nucleation of ferrite grains in this region. Thus, ferrite formed lamella grains with M3C carbide. Besides the ferrite grain, the M3C carbide formed for the same reason for high carbon content of the FCC matrix near the BCC grain. Therefore, alternating layers of M3C and ferrite grains form pearlite layer structure.
In addition to the layers of M3C carbide in the pearlite structure, we also observed layers of M23C6 carbide, too. The orientation relationships between the M23C6 carbide and BCC grain are the K-S orientation relationships. The pearlite-like structures are composed of M23C6 carbide and BCC grains.

1. T. Takahashi, W.A. Bessett, Sci. Mag. 145, 483(1964).
2. E.C. Bain and H.W. Paxton, Alloying Elements in Steel, 2nd ed.,
American
Society for Metals, pp. 18 (1966).
3. 劉禎祥、蔡全華，”鑄鋼實務”，中華民國鑄造學會，技術資料No. 169(1991)。
4. G. Krauss, Principles of Heat Treatment of Steel, ASM, pp.17 (1980).
5. D.A. Porter and K.E. Easterling, Phase Transformations in Metals and
Alloys, 2/e, 263 , Nelson Thornes Ltd,(1992).
6. C.R. Hutchinson, R.E. Hackenberg, G.J. Shiflet, Acta Materialia 52, 3565
(2004).
7. R.W.K. Honeycombe and D.H. Bhadeshia, Steels Microstructure and
Properties,
2nded(1995).
8. S.A. Hackney and G.J. Shiflet, Acta metal. V35, 5, 1007 (1987).
9. S.A. Hackney and G.J. Shiflet, Scripta Metall, 19, 757(1985)
10. F.H. Samuel and A. A. Hussien, Transaction ISIJ, 23, 65(1983).
11. C.R. Hutchinson, G.J. Shiflet, Scripta Mate 50 (2004)..
12. C.R. Hutchinson, R.E. Hackengerg, G.J. Shihlet, Acta Mate, 3565 (2004)
13. T.B. Massalski, Binary Alloy Phase Diagrams.
14. P. Villars, A. Prince, and H. Okamoto, ” Handbook of ternary alloy phase
diagrams”.
15. J.B. Lupton, S. Murphy and J.H. Woodhead, Metall. Trans. A, 3, 2923 (1972).
16. Y.L. Lin and C.P. Chou, Scripta Metall., 27, 67 (1992).
17. D.N. Shackleton and P.M. Kelly, Acta Metall, 15, 979 (1992).
18. Z Nishiyama, ”Martensitic Transformation”, 12 (1978).
19. J.B. Lupton, S. Murphy and J.H. Woodhead, Metall. Trans. A, 3, 2923 (1972).
20. Colombier and Hoffman, Stainless and Heat Resisting Steel, Edward Amold,
(1967).
21.薛凱云，“鐵-12錳-4鋁-0.5碳合金鋼之亞共析型反應研究”，國立台灣科技大學，碩
士論文(2007).
22. D.B. Williams and C.B. Carter, “Transmission Electron Microscopy”,
Plenum (1996).
23.陳力俊等，“材料電子顯微鏡學”，國科會精儀中心(1997)。