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研究了 Ｆｅ—２８Ａｌ－５Ｃｒ与 Ｆｅ—２８Ａｌ－５Ｃｒ—０．５Ｎｂ—０．１Ｃ合金的高温变形行为，发现温度在 ８５０ ℃左右，应变速率为 ８．３３Ｘ１０－４ｓ－１时，呈现出大晶粒的超塑性变形行为，延伸率分别达到 １４５％ 和２５４％．这意味着不需要获得细晶的特别工艺处理就可以直接进行超塑性成形，与传统细晶导致超塑性 不同，其激活能分别为 ２４３ｋＪ／ｍｏｌ和 ２１８ｋＪ／ｍｏｌ，变形机理为位错运动而不是品界滑动，在较低的应 变速率及大约 ８５０ ℃下制备出壁厚为 １．７～２ｍｍ，直径为 ５０ｍｍ的薄壁管坯 分别用电子束焊（ＥＢＷ） 及钨极氩弧焊（ＧＴＡ）两种方法对厚度为 ２ｍｍ左右的 Ｆｅ－Ａｌ基合金试样进行了可焊性及焊接工艺优化 研究电子束焊在真空中进行，集中的高能量输入使熔合区组织细化，可实现对 Ｆｅ３ＡＩ基合金的焊接 采 用钨极氩弧焊时，以中低碳铬钼钢为填充料，降低焊接电流和热输入，对焊件采用适当的预热、缓冷工艺， 是焊接工艺优化的主要因素，应用可焊性及焊接工艺优化研究的结果，制备出相应尺寸的薄壁焊管
The deformation behavior of Fe-28Al-5Cr and Fe-28Al-5Cr-0.5Nb-0.1C alloys was investigated. The results show that when the temperature is about 850 ℃ and the strain rate is 8.33X10-4s-1, The superplastic deformation behavior and elongation of the pellets reach 145% and 254% respectively. This means that superplastic forming can be carried out directly without the special processing of fine grains, which is different from that of the conventional fine grains. The activation energies are 243 kJ / mol and 218 kJ / mol, respectively. The deformation mechanism is dislocation motion instead of Product sliding, at a lower strain rate and about 850 ℃ prepared a wall thickness of 1.7 ~ 2mm, a diameter of 50mm thin-walled tubes were electron beam welding (EBW) and TIG (GTA ) Two methods on the thickness of about 2mm Fe-Al-based alloy samples were welded and welding process optimization Study Electron beam welding in a vacuum, the concentrated high-energy input fusion zone organization refinement can be achieved Fe3AI-based alloy welding with TIG welding, low-carbon chromium-molybdenum steel as filler, to reduce the welding current and heat input, the weldment using the appropriate preheating, slow cooling process is the main optimization of the welding process Factors, application of weldability and welding process optimization of the results of the study, the corresponding size of the thin-walled welded pipe