鐵錳鋁合金鋼具有取代鉻系不鏽鋼的潛力，被稱為窮人的不鏽鋼，而錳鋁鋼相變化的研究則是提供發展鐵錳鋁不鏽鋼的重要基礎。本論文為研究合金成份Fe-10 Mn-9 Al-0.16 C (合金A)與Fe-25 Mn-9 Al-0.13C (合金B)經1300℃與1200℃高溫處理後空冷與水冷及恆溫處理後之相變化。於高溫處理後空冷，合金A與B皆可觀察到肥粒體基地還有魏德曼組織在晶界生成；若以水淬的方式冷卻，則可以觀察到肥粒體晶粒內有麻田散體相。對高溫空冷的試片做穿透式電子顯微鏡分析，魏德曼組織中只有在合金B發現L12析出；而在肥粒體基地中，合金A與合金B皆有D03析出。在高溫空冷的過程中先發生spinodal相分離再經有序化反應後可觀察到L12與D03析出物析出，並藉由STEM的面掃描推測，應有鋁元素有序化反應後的叢聚現象。合金A經1100℃固溶處理後，再於900℃至500℃以100℃為區間持溫熱處理100小時後皆為肥粒體與沃斯田體組成之雙相結構，β-Mn 相存在的溫度範圍，介於800℃至500℃之間，α- Mn 相存在的溫度範圍介於600℃至500℃之間。

Fe-Mn-Al alloy steel has the potential to replace chromium-based stainless steels and is known as the poor man's stainless steel. The study of phase transformations is the basis for the development of Fe-Mn-Al stainless steel. This studies the alloy Fe-10 Mn-9 Al-0.16 C (alloy A) and Fe-25 Mn-9 Al-0.13C (alloy B) after high temperature treatment at 1300℃ and 1200℃, air cooling, water quenched and constant temperature treatment phase transformations. After high temperature treatment and air cooling, alloy A and both can be observed that the ferrite and Widmanstätten structure at the grain boundary; if water quenched, martensite is observed in the martrix. The TEM analysis of the high temperature air-cooled test piece showed that L12 precipitation was only found in the Widmanstätten structure of alloy B; both alloy A and alloy B had D03 precipitated in the martrix. In the process of high temperature air cooling, the spinodal phase transformation occurs first, and then ordering reaction, L12 and D03 precipitates can be observed. Based on the surface scanning of STEM, it is inferred that there should be rich region after the ordering reaction of aluminum. Alloy A is solution treatment at 1100°C, and then heated at 900°C to 500°C at 100°C for 100 hours. It is a two-phase structure composed of ferrite and austenitic. The temperature range of the β-Mn phase is between 800°C and 500°C, and the temperature range where the α-Mn phase exists is between 600°C and 500°C.

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