TK Stainless
TK Stainless
TK Stainless
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high-performance materials<br />
MaGaZine<br />
speCiaL aLLoy For The eCo-FrienDLier poWer pLanT<br />
GeneraTions oF The FuTure<br />
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As part of a team of power plant operators, boiler manufacturers and component<br />
producers, ThyssenKrupp VDM has developed a material which helps boost<br />
the performance of power plants. Modern plants have an energy conversion<br />
efficiency (ratio of energy input to energy output) of around 43 percent.<br />
Increasing temperatures and pressure permits higher conversion efficiencies<br />
which in turn reduce CO2 emissions. Attention is focusing in particular on<br />
so-called 700 degree technology, which will operate at temperatures of 700<br />
degrees and a pressure of 350 bar. “This new power plant generation needs<br />
materials capable of meeting the extremely high requirements involved,” says<br />
Dr. Jutta Klöwer, head of research and development at ThyssenKrupp VDM in<br />
Werdohl. “We have developed an alloy which has already proved its suitability<br />
in extensive testing.”<br />
Nickel-based superalloys are already an established part of the gas<br />
turbines used in combined cycle power plants. The development of 700°C<br />
technology means they must now also be used in the boilers and steam<br />
turbines of coal-fired power plants. In collaboration with power plant operators<br />
and manufacturers, ThyssenKrupp VDM developed the special alloy Nicrofer<br />
5520CoB-alloy 617b specifically for use in power plant boilers. It is based on<br />
the gas turbine material Nicrofer 5520Co-alloy 617. “By adding boron and<br />
controlling the content of strength-enhancing elements such as aluminum,<br />
titanium and cobalt, we succeeded in increasing the permissible mechanical<br />
stresses by 20 percent,” says Dr. Jutta Klöwer. “That allows engineers to use<br />
thinner-walled parts.”<br />
Pipes and components made from this alloy are already being used<br />
in a test plant in North Rhine-Westphalia – construction work on the first 700<br />
degree power plant is scheduled to start in 2010. “The next step is to validate<br />
the cost-effective production of standard components from this alloy,” says<br />
Dr. Jutta Klöwer. “This will focus in particular on the extremely high quality<br />
requirements made by power utilities on boiler materials.” But research work<br />
is continuing: Engineers are already working on materials for the next-butone<br />
generation of coal-fired power plants. And not without reason: By the year<br />
2030, global demand for electricity is expected to double. Innovations in the<br />
technology and materials of fossil-fueled power plants will play a key role in<br />
protecting the environment and conserving resources. ---<br />
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