鐵錳鋁合金鋼是屬於沃斯田體系不銹鋼，其密度與原料成本是低於傳統的鎳鉻系不銹鋼，故鐵錳鋁不銹鋼是有可能取代部分傳統鎳鉻系不銹鋼而成商業化的低密度不銹鋼。只是要商業化鐵錳鋁不銹鋼是需建立許多資料庫，例如合金鋼相變化的研究資料等。本論文即研究三種鐵錳鋁合金經1195℃至1100℃的高溫淬火處理後的相變化情形；以方位影像顯微鏡(OIM)與穿透式電子顯微鏡(TEM)附加的ASTAR分析儀，分析此三種合金的相組成，並判定相變化形式。
本團隊曾以TEM仔細研究鐵-16.7錳-3.4鋁合金(合金A)的相變化：合金A於1100℃的溫度時，其組成相為沃斯田體；而後經由淬火處理後，大部分的沃斯田體會相轉變為麻田散肥粒體，剩餘的基地相則成為殘留沃斯田體。本論文得以ASTAR分析儀快速確認以上的實驗結果。
本研究團隊亦曾研究鐵-15.9錳-4.2鋁合金(合金B)的相變化：合金B於1100℃的溫度時，其組成相為肥粒體與沃斯田體的雙相組織；而後經由淬火處理，於雙相組織中發現肥粒體雙晶，然而前人誤判此為存在於肥粒體晶粒內的退火雙晶。本研究確認合金B於1195℃至1100℃的組成相為肥粒體與沃斯田體。於TEM-ASTAR的分析中，更發現原沃斯田體晶粒存在著BCC麻田散體以及殘留沃斯田體；故更正先前研究的誤判，此肥粒體雙晶是由原沃斯田體晶粒經由麻田散體相變化所產生的。
本論文亦使用OIM分析合金C(鐵-27.6錳-5.3-0.11碳)的組成相，其於1200℃至1100℃的高溫相組成為肥粒體與沃斯田體。經由高溫淬火處理後，此雙相組織中的沃斯田體晶粒未有麻田散體相變化的發生。此與碳鋼的麻田散體相變化不同。

Fe-Mn-Al alloys which are lower desity and lower cost of the material than the traditional Ni-Cr steel system belong to austenite steels system. Thus Fe-Mn-Al alloys have gained much attention as cheap substitutes for some of the conventional Fe-Ni-Cr stainless steels to become commercial stainless steels with the low density. However, to make it become commercial stainless steel requires building the data base such as phase transformation of steel alloys data. Due to this facts, we mainly discuss phase transformation of three different components of Fe-Mn-Al alloys after quenching process from 1195℃ to 1100℃ in this study. We use orientation imaging microscopy (OIM) and transmission electron microscope (TEM) equipped with ASTAR software to identify the phases and phase transformations between these three alloys.
According to the former reaserch, the alloy A which is content with Fe-16.7Mn-3.42Al (wt %) is the single austenite phase at 1100℃. After quenching, the austenite phase will transform into BCC martensite and the rest will become retained austenite. We comfirm the results by TEM-ASTAR rapidly analyzing.
In addition, the former reaserch group considered alloy B which are content with Fe-15.9Mn-4.2Al (wt %) are ferrite and austenite phase on 1100℃. After quenching, they found out there were BCC twins in the dual phases. But the result of annealing twins consisting in the ferrite was not correct. In this study, we use TEM-ASTAR to analysis alloy B and we conclude that alloy B are ferrite and austenite phases from 1195℃ to 1100℃. Furthermore, we find out there are BCC martensite and retained austenite existing in alloy B after quenching. So we conclude that the former research group think the BCC annealing twins within the alloy B is wrong. Actually, there are BCC martensite and retained austenite in the alloy B rather than BCC annealing twin.
The alloy C which is content with Fe-27.6Mn-5.3Al-0.11C (wt %) is composed of ferrite and austenite phase from 1195℃ to 1100℃ by the OIM analysis. We conclude that there are ferrite and austenite phases within alloy C. However, there are no ausrenite grain transformed into BCC martensite in quenched alloy C to be found. So the pahse transformation is diffrerent from the carbon steels.

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