The Osprey Process

Abstract

Figs. 3 and 4. It can be seen that both materials exhibit a fine, uniform microstructure without any evidence of prior particle boundaries. The grain size in both cases is in the range 6-8 ASTM and the microporosity present is discrete and uniformly distributed. This type of structure is extremely amenable to forging so that even alloys which can normally be produced only in the cast form have been forged (in one blow on a high energy rate machine) to a finished shape. The microstructures after being worked are very similar to those of the preforms shown in Figs. 3 and 4. Properties have been determined from specimens taken from the load cell forging blank shown in Fig. 2 and these have been compared with data for the same alloys produced by conventional routes. For example, Table I shows such a comparison for En24 and 12%Cr stainless steel. A close similarity exists between the properties of Osprey forgings and the longitudinal properties of conventional forgings, but the Osprey values for elongation and impact are superior to the transverse conventional results. Such properties, however, do not necessarily iridicate suitability