Main achievement of the first phase and aim of the second phase.
The first term of the ultra-steel research project which started in April 1997, was completed
in March 2002.
Four kinds of ultra-steels having double strength and double lifetime were
successfully developed on a laboratory scale during this term. Moreover,
the basic technologies for structure fabrication by welding and epoch-making
analytical and evaluation methods were achieved based on new concepts.
We have set up the following goals for the next term, “the development
of a factor 4 materials having both double strength and lifetime”, “the
development of a processing method for large-sized materials”, and “a
construction method for innovative structures using ultra-steels”. We
believe that these research subjects will make significant contributions
to “the construction of modern urban infrastructures” and “the realization
of highly efficient fossil-fired power plant”. In addition, we plan to
propose a new design of steel structures, which utilizes ultra-steels effectively, by collaboration with architects and
designers of structures.
The following main subjects (taskforce) are specifically set up and research will be promoted bringing into a view of the characteristic evaluation by the examination which was carried out by simulating the real environment from manufacture of the ultra-steel structure model which becomes new structure and a design.
By developing refinement technology, the
subject which creates ‘factor 4’ ultra steel with both high strength and
corrosion-resistant in thick plate size, subject which manufactures a structure
model by ultra-narrow gap GMA welding and high power pulse CO2 laser welding processes developed in the 1st term, and the subjects of
the invention of the 2000MPa-class bolt in the chemical compositions with
corrosion resistance and the joining with bolts that is expected to become
the mainstream in on-site construction are taken on. The systems development
for evaluating dynamics factors and environmental factors for the Ultra
Steel structure model in simulated exposure test is aimed at.
Towards realization of
ultra-supercritical steam boiler, based on the material design which
stabilizes the microstructures near the grain boundary for a long time, while
achieving creation of a large thickness pipe like as the main steamy pipe etc.
, control of the type IV creep crack by the formation of the thin welding HAZ
width, and the improvement of oxidation-resistance in the high temperature
steam by the surface protection film, a new structure with heat-resistant steel
are attained.
Moreover, with respect to much of the seeds technology which was acquired
in the 1st phase of the ultra-steel research in addition to these two subjects
(task force), the material basic data that contain development material
utilizing the elucidation of mechanism of the unsolved phenomenon and establishment
of a guiding principle, and analysis and evaluation technique of many classes
over nano-meso-macro are accumulated.