Enabling Technology Project
New Heat Resistant Materials for Low CO2 Emission Type Next-Generation Thermal Electric Power Generation
Outline of the area
National Institute for
42% of the global CO2 emission is caused by thermal electric power generation. In addition, since the amount of the thermal electric power generation which occupies 68% of the current total electric power in the world is estimated to increase 1.4 times over or more in 2040, it is strongly requested that a next-generation thermal electric power generation system of the low CO2-emission will be created.
Due to the law of thermodynamics, the thermal engine commencing with the gas turbine increases its electric power generation efficiency by operating at a high temperature thereby being an extremely effective means for decreasing CO2 emission. The largest factor limiting the operational temperature is heat resistant materials. It is indispensable to develop a new ultrahigh heat resistant material which complies with the requirement for the operation at high temperature and high efficacy in various methods such as coal-fired thermal power, natural gas-fired power and so on.
In this project, we will seek to further promote the ALCA R&D so far as follows: (a) materials allowing higher efficiency thermal electric power generation such as gas turbine at 1800°C and thermal electric power generation at 800°C, (b) ferrite heat-resistance steel for thermal electric power generation at 700°C, (c) recyclable Ni-based superalloy.
In this way, we establish a basis for the empirical research in collaboration with industry in 5-years and social implementation in 2030 as well.
Development of Direct and Complete Recycling Method for Superalloy Turbine Aerofoils
Research Adviser, National Institute for Materials Science
The purpose of this ALCA research is to reduce CO2 emission by improving thermal efficiency and lowering the consumption of fossil fuel, and is also to largely disseminate the several kinds of gas turbines made with the direct and complete recycling method of the next-generation superalloy turbine blade material for which the higher cost is constrictive for its dissemination by reducing the life time cost to one fourth. There are two causes for alloy composition change and material deterioration; (i)change of main element concentration by the diffusion from metal coating and (ii)a contamination of impurity element depending on the environment such as sulfur. We aim to suppress them, to establish the recyclable technology while maintaining 100% strength and oxidation resistance, and to scale up to the extent that we can produce a large ingot.
We conduct research on recyclable technology that re-uses a turbine blade as a material having the equivalent or more of the original superalloy by re-solving the used nickel-base superalloy turbine blade in calcia crucible, removing impurities such as sulfur.
Advanced Design and Casting Process Development of MoSiB-Based Ultra-High Temperature Materials
Professor, Tohoku University
In order to develop advanced high-pressure turbine blades able to use above 1500°C with no cooling system, Mo-Si-B-based novel ultra-high temperature materials are designed with pioneering concepts and their material properties are experimentally researched. Furthermore, toward the practical use of the ultra-high temperature materials, casting techniques possible to obtain a large-scale ingot applicable to high-pressure turbine blades are challenged to develop.
Integrated Research of Next-Generation Ultra-Heat-Resistant Ferritic Steels through Efficient Use of Nitrogen
Professor, Kyushu University
The application of boiler tube for next-generation thermal electrical power generation at 700°C with high efficiency and low CO2 emission is supposed to develop a high strength thermal resistant steel. By effectively adding nitrogen which is a low cost and exhaustless elemental resource, compatibility of strength at high temperature and economy is targeted. While nitrogen has received less attention as an additive element for the steel, the developed steel in the present research has achieved 10 times the strength or more at high temperature compared with the existing steel, indicating a possibility of new material design. In the future, we will proceed with our efforts to further improve the strength and the application into actual equipment.
Development of MoSi2-Based Brittle/Brittle Multi-Phase Single-Crystal Alloys
Professor, Kyoto University
Under an entirely new concept of Brittle/Brittle multi-phase material, super high-temperature materials based on MoSi2 will be developed by simultaneously achieving high thermal stability of microstructures, high strength and high toughness through controlling atomic structures of interphase boundaries and partitioning and segregation behaviors of alloying elements. In addition, we contribute to the realization of the burning temperature of 1800°C in gas turbine engines, which cannot be achieved with conventionally available alloys.
Elemental Technology for Design and Manufacturing of Innovative 1073K Class Super Austenitic Heat-Resistant Steels
Professor, Tokyo Institute of Technology
It is possible to develop Fe based alloys with excellent creep resistance compatible to Ni based alloys!! In the first stage of ALCA project, we have worked on designing Fe based alloys as a potential heat resistant material for 800 °C class AUSC power plants with signifi cantly increased efficiency, where we have established a design principle using a new strengthening mechanism, “grain boundary precipitation strengthening (GBPS)” and have demonstrated a possibility of its industrialization from the view of both creep strength and steam oxidation resistance. In the present project, we are going to develop elemental technologies for manufacturing steel pipes for boiler heat exchangers and turbine casing materials based on the established design principle with industrial partners.