Abstract
n order to increase the energy efficiency of steam power plants, one has to increase the operating parameters like steam temperature and pressure. The use of (highly) heat resistant steel grades is the state of the art in power plant engineering, but these materials have
technical limitations e.g. creep strength and oxidation resistance.
The replacement of steels by nickel-based alloys and/or the combination of steels and nickel-based alloys by dissimilar-weld-joints could be the solution.
Sand castings are main structural parts in steam turbine construction (e.g. valves and casings). Therefore, voestalpine Giesserei Traisen GmbH, Austria has successfully developed a manufacturing process for thick-walled sand castings made of nickel-based
alloys. The production is done within the technical infrastructure of a conventional steel foundry. The major goals are to identify and optimize all necessary process parameters in order to accomplish a technological transfer of steel-specific production-related parameters to nickel-based alloys.
A brief introduction in the production steps of manufacturing sand castings made of nickel-base alloys is given. The main differences between steel castings and nickel-based castings are
summarized. Investigations and experimental work on dissimilar welding of the Alloy 625 with the martensitic 9% Cr-steel COST CB2 by three different welding procedures are discussed. The
joining of these materials is one of the main challenges facing the welding community due to hot cracking of the weld joints.
The paper summarizes the status of the Research and Development at voestalpine Giesserei Traisen and identifies the challenges and process improvements
technical limitations e.g. creep strength and oxidation resistance.
The replacement of steels by nickel-based alloys and/or the combination of steels and nickel-based alloys by dissimilar-weld-joints could be the solution.
Sand castings are main structural parts in steam turbine construction (e.g. valves and casings). Therefore, voestalpine Giesserei Traisen GmbH, Austria has successfully developed a manufacturing process for thick-walled sand castings made of nickel-based
alloys. The production is done within the technical infrastructure of a conventional steel foundry. The major goals are to identify and optimize all necessary process parameters in order to accomplish a technological transfer of steel-specific production-related parameters to nickel-based alloys.
A brief introduction in the production steps of manufacturing sand castings made of nickel-base alloys is given. The main differences between steel castings and nickel-based castings are
summarized. Investigations and experimental work on dissimilar welding of the Alloy 625 with the martensitic 9% Cr-steel COST CB2 by three different welding procedures are discussed. The
joining of these materials is one of the main challenges facing the welding community due to hot cracking of the weld joints.
The paper summarizes the status of the Research and Development at voestalpine Giesserei Traisen and identifies the challenges and process improvements
| Original language | English |
|---|---|
| Title of host publication | 2011 International Gas Turbine Congress |
| Number of pages | 8 |
| Publication status | Accepted/In press - 2011 |
| Event | 2011 International Gas Turbine Congress - Osaka, Japan Duration: 13 Nov 2011 → 18 Nov 2011 |
Conference
| Conference | 2011 International Gas Turbine Congress |
|---|---|
| Country/Territory | Japan |
| City | Osaka |
| Period | 13/11/11 → 18/11/11 |
Fields of Expertise
- Advanced Materials Science
Treatment code (Nähere Zuordnung)
- Application
- Experimental
