"Process development for the production of FeAl components for combined-cycle gas turbine (CCGT) power plants".
There are several possibilities to increase the efficiency and cost effectiveness of combined cycle gas turbines. Increasing efficiency can be made possible by raising the operating temperatures. This requires a material that is suitable for the higher operating temperatures and associated higher thermal loads. At the same time, the material substitution should not increase the costs for the production and the material, or only slightly. Therefore, a material system is sought which, on the one hand, has good high-temperature resistance and, on the other hand, can be easily machined at room temperature. By the appropriate choice of alloying elements and the renunciation of complex and cost-intensive treatments such as hot isostatic pressing (HIP), the costs, of the currently used alloys should not exceed. In detail, the system of intermetallic iron aluminides will be investigated.
The aim of this project work is the development and manufacture of components made of high-temperature iron aluminides for use in gas and steam combined cycle power plants. The focus of material development is on the balance between machinability at room temperature and high-temperature strength. The focus for the Lightweight Construction Competence Center at Landshut University of Applied Sciences is on investigating the mechanical material properties. Particular attention will be paid to fatigue properties in LCF and TMF.
The project involves developing an FeAl alloy that exhibits both good creep properties and good machinability at room temperature. A major task is to refine the microstructure to increase room temperature ductility. However, creep resistance must not be neglected. A compromise between room temperature machinability and high temperature strength must be found. This is realized by the introduction of different grain refining agents. The task in the first stage of the project is to verify the properties of various grain refining agents on two different alloys. In addition to an analysis of the microstructure and grain size, the corrosion properties and mechanical properties will be investigated. Furthermore, different heat treatment conditions will be analyzed. In detail, tensile tests at room temperature and high temperatures, as well as creep tests with strain rates up to 10^-9 s^-1 will be performed on the LLK. The alloy with the best properties will be further investigated in the next step. In addition to the linear tests, cyclic tests in the form of fatigue tests in the LCF and TMF range will also be carried out. In parallel, the corrosion and welding properties as well as the behavior as a turbine material will be investigated by means of FEM and CFD simulations. The project culminates in the production of demonstrator components, which are tested in realistic trials.
The following companies and institutes are involved in this project:
Otto Junker GmbH is the foundry responsible for alloy development and weldability testing.
The Chair of Corrosion and Corrosion Protection at RWTH Aachen University is analyzing the corrosion behavior of the selected alloys.
As part of the project, the company B&B-Agema GmbH is developing a blade geometry adapted for FeAl for steam and gas power plants and validating it in FEM and CFD simulations.
The project leader is Access e.V. This is a spin-off of RWTH Aachen University, which operates as an independent research center. Access eV's tasks in the project include casting and alloy investigation.
Data & Facs
|Process development for the production of FeAl components for combined-cycle power plants (CCPP)
|Materials development, intermetallic alloys, high temperature strength, mechanical properties, fatigue, creep
|4 years (05.2017 until 07.2021)
|6th Energy Research Program "Research for an environmentally friendly, reliable and affordable energy supply" (BMWi)
|Scientific staff / Technical project management
|M.Eng. Eva Kollmannsberger
|Overall project management
|Prof. Dr.-Ing. Holger Saage