Influence of annealing on mechanical properties of an Fe-28Al-4Cr-0.1Ce alloy

Structure and mechanical properties of a vacuum-cast and hot-deformed Fe-28 Al-4Cr-0.1Ce (at%) alloy were studied. Samples were hot-forged or hot-extru ded and afterwards annealed above or below the point of the B2-D0(3) order- order transition (T-c similar to 540 degrees C). Mechanical properties were evaluated from Vickers hardness, tensile, compression and three-point bend tests. Structure was examined by optical and electron metallography. Besid es large particles in the matrix, which contain Ce, Cr-Fe precipitate has a lso been found on the grain boundaries. Annealing at 700 and 800 degrees C leads to recovery of the dislocation structure and to the corresponding dec rease of the yield stress. Even during low-temperature annealing in the ran ge between 350 and 510 degrees C the yield stress decreases at each of the annealing temperatures due to the growth of the ordered domains. Room tempe rature ductility after hot extrusion and annealing for 2h at 700 degrees C reached 4.3%. (C) 1999 Elsevier Science Ltd. All rights reserved.