Computational Materials Design of Castable SX Ni-based Superalloys for IGT Blade Components

 

Performer: 
QuesTek Innovations LLC
A single-crystal model blade (length: 170mm)
A single-crystal model blade (length: 170mm)
Website:  QuesTek Innovations LLC
Award Number:  SC0009592
Project Duration:  02/19/2013 – 04/14/2016
Total Award Value:  $1,149,360.00
DOE Share:  $1,149,360.00
Performer Share:  $0.00
Technology Area:  Advanced Energy Systems
Key Technology:  Hydrogen Turbines
Location: 

Project Description

QuesTek Innovations LLC (QuesTek) is a leader in computational materials engineering and will employ a systems engineering design framework based on existing CALPHAD (CALculation of PHAse Diagrams) multicomponent tools. QuesTek will invoke reliable physics-based models to predict intrinsic freckling potency, alloy hot-tearing tendency during casting, and other casting related defects. The computational materials design will consider trade-offs between the blade property requirements such as creep strength, resistance to topologically close-packed phase formation, tensile strength, corrosion resistance, grain-boundary strength, and SX processing requirements such as freckling resistance, hot-tearing resistance, and a solution heat-treat window that avoids incipient melting. The Phase I focus will be on computationally designing candidate alloys that can provide enhanced castability while achieving increased metal temperature capability of 1050–1100 degrees Celsius. The Phase II program will focus on developing the entire systems-based materials design and validation through casting complex blade components with internal cooling passages using actual OEM (original equipment manufacturer) blade tooling.

QuesTek plans to collaborate with key stakeholders to define specific property goals and processing constraints that will enhance QuesTek’s process-structure models for castability and structure-property models for superalloy design, sketch out microstructural concepts capable of achieving the program goals, and use the enhanced tools to design SX superalloy compositions incorporating these microstructural concepts. Also, QuesTek plans to fabricate baseline commercial alloy compositions (or variants of these compositions) as demonstration IGT tooling castings to characterize their casting behavior and compare it against QuesTek’s model predictions. These model castings and the comparison against predictions will serve as a Phase I concept feasibility demonstration.

Project Benefits

Turbines convert heat energy to mechanical energy by expanding a hot, compressed working fluid through a series of airfoils. Combustion turbines compress air, mix and combust it with a fuel (natural gas, coal-derived synthesis gas [syngas], or hydrogen), and then expand the combustion gases through the airfoils. Expansion turbines expand a working fluid like steam or supercritical carbon dioxide (CO2) that has been heated in a heat exchanger by an external heat source. These two types of turbines are used in conjunction to form a combined cycle— with heat from the combustion gases used as the heat source for the working fluid— improving efficiency and reducing emissions. If oxygen is used for combustion in place of air, then the combustion gases consist mostly of carbon dioxide (CO2) and water, and the CO2 can be easily separated and sent to storage or used for Enhanced Oil Recovery (EOR). Alternatively, the CO2/steam combustion gases can be expanded directly in an oxy-fuel turbine. Turbines are the backbone of power generation in the US, and the diverse power cycles containing turbines provide a variety of electricity generation options for fossil derived fuels. The efficiency of combustion turbines has steadily increased as advanced technologies have provided manufacturers with the ability to produce highly advanced turbines that operate at very high temperatures. The Advanced Turbines program is developing technologies in four key areas that will accelerate turbine performance, efficiency, and cost effectiveness beyond current state-of-the-art and provide tangible benefits to the public in the form of lower cost of electricity (COE), reduced emissions of criteria pollutants, and carbon capture options. The Key Technology areas for the Advanced Hydrogen Turbines Program are: (1) Hydrogen Turbines, (2) Supercritical CO2 Power Cycles, (3) Oxy-Fueled Turbines, and (4) Advanced Steam Turbines.

Hydrogen turbine technology research is being conducted with the goal of producing reliable, affordable, and environmentally friendly electric power in response to the Nation's increasing energy challenges. NETL is leading the research, development, and demonstration of technologies to achieve power production from high hydrogen content (HHC) fuels derived from coal that is clean, efficient, and cost-effective; minimize carbon dioxide (CO2) emissions; and help maintain the Nation's leadership in the export of gas turbine equipment. These goals are being met by developing the most advanced technology in the areas of materials, cooling, heat transfer, manufacturing, aerodynamics, and machine design. Success in these areas will allow machines to be designed that have higher efficiencies and power output with lower emissions and lower cost.

QuesTek Innovations, LLC will employ a systems engineering design framework based on existing CALPHAD (CALculation of PHAse Diagrams) multicomponent tools and invoke reliable physics-based models to predict intrinsic freckling potency, alloy hot-tearing tendency during casting, and other casting related defects. Manufacturing research conducted under the Advanced Turbine Program seeks to develop existing or novel manufacturing processes that will improve yields, reduce defects, lower costs, and enable component designs that were previously unattainable. These improvements will lower capital costs, improve turbine efficiency, and reduce maintenance, leading to reduced operating costs, and reduced costs of electricity for consumers.


Contact Information

Federal Project Manager 
Steven W. Richardson: steven.richardson@netl.doe.gov
Technology Manager 
Richard Dennis: richard.dennis@netl.doe.gov
Principal Investigator 
Gregory Olson: golson@questek.com
 

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