Chrome Oxide Refractory
One notable NETL success is the development of a chrome oxide refractory material capable of working in slagging gasifier conditions. In this project, researchers first determined that one of the major failure mechanisms for chrome oxide refractories exposed to the intense heat and corrosive environment was spalling, or the chipping or flaking of refractory material from an exposed face. They used this information to formulate a high-chrome oxide refractory composition that resists spalling, resulting in a refractory with a longer service life in the gasifier.
Inside an ultrasupercritical (USC) pulverized coal power plant, materials are exposed to temperatures up to 760 °C and pressures up to 5,000 psi. Operating a USC system can improve power plant efficiency up to 47 percent and reduce emissions. However, finding boiler and turbine materials that can hold up under extreme conditions requires new high-temperature metal alloys and ceramic coatings, as well as computational modeling research to optimize the processing of these materials. Advanced Research Materials Development program successes in this area include the following.
- Babcock & Wilcox researchers have identified ferritic steels that resist steam oxidation at high temperatures as well as—or better than—more expensive austenitic steels.
- Researchers at ALSTOM Power have shown that applying advanced coatings to less expensive alloy compositions provides an alternative to using costly, highly alloyed materials for next-generation boiler designs.
- Investigators at Riley Power Inc. have developed and met ASME standards for a welding procedure for an advanced steel known as SAVE 12. This high-chrome alloy is a candidate material for construction of advanced coal-fired boilers.
- University of Cincinnati researchers have found that ceramics based on mixed metal niobates and tantalates are particularly promising as protective coatings against aggressive environments associated with the high temperatures of USC boilers.
- Researchers at Oak Ridge National Laboratory have developed a neural net program to guide heat treatment procedures for advanced alloys. These improved methods can increase the energy efficiency of the process and reduce waste.
The Advanced Research Materials Development program couples these cooperative, cutting-edge R&D efforts with technology transfer mechanisms to help maintain U.S. materials technology capabilities and competitiveness.