材料期刊网

In order to evaluate the deformation characteristics of spray formed superalloy GH742 and determine the appropriate forging procedure of the alloy on this basis, the influence of deformation temperature and strain rate on the ductility of spray formed GH742 was investigated by using the Gleeble-3500 thermal-mechanical testing machine. It is shown that the forgeability of spray formed GH742 is better than conventional GH742 by ingot metallurgy because of refined grain structure and enhanced chemical homo-geneity of spray formed GH742. In the temperature range of 1020 to 1100℃, the ductility of spray formed GH742 is dependent on the deformation temperature and is increased linearly in proportion to the increment of deformation temperature, which is more than 40% at 1020℃ and more than 60% at the temperature between 1100 and 1140℃. Furthermore, the results indicate the flow stress is affected considerably by the deformation temperature and strain rate. In the temperature range of 1020 to 1140℃, the maximum flow stress of spray formed GH742 increases with the increment of strain rate and decreases with the increment of the deformation temperature.