Material selection for high temperature applications

In this paper several materials have been evaluated in order to select the best suitable alloy for the production of a gas turbine transition piece. These components are exposed to complex thermal stresses and different damages, each of them requiring particular characteristics of the material. The procedure described takes into account the variability of requirements with some parameters, in particular temperature and service time. Due to the high value of temperature and the constraint of ductility, the choice of material has been limited to superalloys and stainless steels. A comparison between several alloys has been carried out on the basis of constraints and requirements previously determined. Using a suitable objective function, the method allows ranking materials in order to find the alloy which maximise component's performance.