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Full-Text Articles in Metallurgy
Microstructure And Creep Deformation Behavior Of A Hierarchical-Precipitate-Strengthened Ferritic Alloy With Extreme Creep Resistance, Gian Song
Doctoral Dissertations
Hierarchical NiAl [nickel-aluminium compound]/Ni2TiAl [nickel-titanium-aluminum compound] or single Ni2TiAl-precipitate-strengthened ferritic alloys have been developed by adding 2 or 4 weight percent [wt. %] of Ti [titanium] into a previously-studied NiAl-precipitate-strengthened ferritic alloy. A systematic investigation has been conducted to study the interrelationships among the composition, microstructure, and mechanical behavior, and provide insight into deformation micro-mechanisms at elevated temperatures.
The microstructural attributes of hierarchical or single precipitates are investigated in the Ti-containing ferritic alloys. Transmission-electron microscopy in conjunction with the atom-probe tomography is employed to characterize the detailed precipitate structure. It is observed that the 2-wt.-%-Ti alloy …
Microstructures And Mechanical Behavior Of Nial-Strengthened Ferritic Alloys At Room And Elevated Temperatures, Zhiqian Sun
Microstructures And Mechanical Behavior Of Nial-Strengthened Ferritic Alloys At Room And Elevated Temperatures, Zhiqian Sun
Doctoral Dissertations
In order to improve the thermal efficiency and decrease the greenhouse gases emission, it is required to increase the steam temperature and pressure in fossil-energy power plants. In the United States, research has been performing in order to push steam temperature to 760 Celsius degree and steam pressure to 35 MPa. However, the highest operational temperature for current commercial heat-resistant ferritic steels is ~ 620 Celsius degree. In this sense, new advanced ferritic alloys with better creep resistance are needed, considering such service conditions in next-generation ultra-supercritical fossil-energy power plants.
Coherent B2-ordered NiAl-type precipitates have been employed to reinforce the …