本論文的合金成分為鐵-20錳-2鋁-0.4碳(wt%)，而此合金鋼為沃斯田體鋼。合金所經之處理為先經熱鍛冷軋後再施以1100°C高溫固溶處理及低溫時效處理。
合金經固溶處理後，沃斯田體晶粒內有條狀麻田散體的析出。經判定此條狀麻田散體具有HCP結晶結構或是FCC的雙晶結構。此結果顯示本合金鋼與未添加鋁之鐵-2錳-0.5碳合金鋼內生成的條狀麻田散體類似，故可知2wt% 鋁的添加量並未對沃斯田體晶粒內之條狀麻田散體析出物的出現造成影響。鋁的添加可以降低合金鋼內之FCC基地的疊差能，以致因疊差移動所造成之相變化，可以因為內應力的釋放，而使已經經過相轉變後之生成相因無應力的支撐Shockley部份差排，而再度回復至原先母相的FCC結晶結構。
於低溫時效後的合金鋼，發現有M23C6碳化物及似波來體組織於沃斯田體晶界處析出。於晶界處析出的M23C6碳化物與沃斯田體基地具有立方晶對立方晶的方位關係，且此碳化物之晶格常數約為FCC基地的3倍，其晶格常數為1.06 nm。而似波來體組織是由層狀的肥粒體及M23C6碳化物所組成。似波來體組織的出現是為沃斯田體相於低溫下分解為肥粒體相與M23C6碳化物的相變化結果。M23C6碳化物與肥粒體兩者之間有方位關係。似波來體中的M23C6碳化物之錳含量遠高過肥粒相，故知M23C6為富錳含量之碳化物。
本合金的似波來體組織存在之上限溫度是介於600至550℃之間。而525℃應為接近恆溫變態曲線的鼻部區域溫度。

We studied the phase transformation of an alloy which was undergone solution heat-treatment at a temperature of 1100oC and followed by aging processes at low temperatures ranging from 900 to 500oC. After the heat treatment, water quenching was utilized. The composition of the alloy is Fe-20wt%Mn-2wt%Al-0.4wt%C.
Needle-like martensites were dispersed within the austenitic matrix after the solution heat treatment. The martensites were composed of HCP structure and FCC twin. Shockley partial dislocations were believed to play an important role for the formation of needle-like martensite. The result is similar to that observed in the alloy with a composition of Fe-21wt%Mn-0.5wt%C. Thus, it is apparent that the addition of Al has no effect on the formation of needle-like martensite. Al lowers the stacking fault energy of the alloy. The movement of Shockley partial dislocation results in the formation of stacking fault. However, the different type of stacking faults could form HCP structure or FCC twins.
Both M23C6 carbide and pearlite-like structure precipitated at the FCC grain boundaries after the aging processes at temperatures below 600oC. The M23C6 carbide has a cubic-to-cubic orientation relationship with the FCC matrix, and its lattice constant was 1.96 nm, three times larger than the matrix. The pearlite-like structure is comprised of lamellar structure of ferrite and M23C6 carbide. In the pearlite-like structure, the Mn content was far richer in M23C6 carbide than that in ferrite. Thus, the M23C6 carbide is rich in Mn.
The upper limit temperature of the pearlite transformation was found between 600 to 550oC. The nose temperature of the TTT curves of the alloy is believed to be around 525 oC.

1.D. William, J.R. Callister, Mat. Sci. and Eng. an Introduction, 5/e, 2000.
2.黃振賢，”金屬熱處理”文京出版社 (2000)
3.McGraw-Hill, The Science and Design of Engineering Materials , 2nd (1999)
4.J. Charles, A. Berghezan, A. Lutts, and P. L. Dancoisne, Metal Progress, pp.71-74 (1981)
5.D.A. Porter and K.E. Easterling, Phase Transformations in Metals and Alloys, 2/e (2001)
6.B. L Bramfitt and A. R. Marder, A Transimission-Electron-Microscopy Study of the Substructure of High-Purity Pearlite, Acta Metall., pp.483-495 (1973)
7.R.E. Reed-Hill, Physical Metallurgy Principles, 3rd ed (1992)
8.劉嵩俊，”耐磨鋼鐵鑄造”，中華民國鑄造學會，技術資料NO.185 (1995)
9.B.K. Zuidema, D.K. Subramanyam, W.C.Leslie, Met. Trans.A 18, 1629 (1987)
10.Donald R. Askeland原著，蔡丕椿等編譯，材料科學與工程第三版，全華出版社 (1999)
11.Goldstein and Newbury, Scanning Electron Microscopy and X-Ray Microanalysis, 3rd, pp147-173 (2003)
12.K.P. Staudhammer, L.E.Murr and S.S. Hecker, Acta Metall.,31, 267 (1983)
13.David B. Williams and C. Barry Carter, “Transmission Electron Microscopy”, Plenum (1996)
14.吳泰伯、許樹恩，“X光繞射原理與材料結構分析” (2006)
15.呂浩，”機械材料”，鼎茂圖書出版社 (2002)
16.徐永霖，’’鐵-21錳-0.5碳合金鋼之非擴散型相變化研究” (2007)
17.劉嵩俊，”耐磨鋼鐵鑄造”，中華民國鑄造學會，技術資料NO.185 (1995)
18.B.K. Zuidema, D.K. Subramanyam, W.C.Leslie, Met. Trans. A 18,1629 (1987)
19.W.C. Cheng, H.Y. Lin, Mater. Sci. Eng. A 323 462/466 (2002)
20.W.C. Cheng , C.F. Liu, Y.F. Lai, Mater. Sci. Eng. A337281/286 (2002)
21.W.C. Cheng , C.F. Liu, Y.F. Lai, Mater. Sci. Eng. Scripta Materialia 48 295–300(2003)
22.W.C. Cheng , C.F. Liu, Y.F. Lai, Mater. Materials Science and Engineering A335 82–88(2002)
23.J.H. Jaw , W.C. Cheng, C.J. Wang Scripta Materialia 51 279–283 (2004)
24.陳力俊等，“材料電子顯微鏡學”，國科會精儀中心(1997)。
25.汪健民，“材料分析”中國材料科學學會(1988)。
26.鮑忠興、劉思謙 近代穿透式電子顯微鏡實務 滄海書局2008
27.林東一，“鐵-21錳-0.5碳合金之麻田散體相變化研究”，國立台灣科技大學，碩士論文(2007)。