Civil Engineering Reference
In-Depth Information
5.4
Future trends
The use of nanotechnology has led to remarkable improvements in the
mechanical properties and corrosion resistance of steels, by achieving the
desirable microstructure of steels via phase transformation or deformation
kinetics or by controlling the key chemistry down to the nanometer scale.
By controlling the grain size and distribution and the heterogeneity and
gradation of microstructure (e.g., quantity, morphology, and distribution of
nano-phases), strength/toughness synergy and other properties of steels
could be greatly enhanced. One interesting research need is to optimize the
distribution and motion of dislocations in nanocomposite steels. Many of
the R&D efforts detailed in previous sections will undoubtedly continue
and more cost-effective solutions will emerge as a result of the advanced
knowledge base and continuous improvements in R&D and in production
technologies (e.g., high N-content SS). The great potential of nanotechnol-
ogy in this fi eld has not yet been fully achieved and in the near future new
techniques and new applications can be expected along with new products
to be introduced into the market. Multi-scale modeling of nanocomposite
steels under mechanical or chemical stresses is crucial to unravel the role
of dislocations, GBs, precipitates, and lattice defects and their interactions
at various length scales. Continued developments in design and processing
technologies can be expected to address needs in long-term durability,
minimized maintenance, environmental sustainability, and/or competitive
performance (e.g., high strength-to-weight ratio). To maximize the sustain-
ability of using steels for construction, it is important to match the steel type
to the working conditions and user requirements.
Nanotechnology has demonstrated its clear benefi ts and will continue to
play a key role in the production of high performance steels. Future devel-
opments will be centered on furthering the understanding of why and how
superior properties of steels can be achieved by the design and control of
their chemical composition and morphology at the micro- and nanometer
scales. Progress in steel production technology will open up the possibility
of rapid change in steel metallurgy and increase the competitiveness of
nano-enabled products. More research is needed to advance the knowledge
base relevant to using nanotechnology to modify the surface layer or bulk
material of steels and to shed light on the mechanisms and pathways defi n-
ing the cause-and-effect relations that link metallurgy and production pro-
cesses with microstructure and properties of steels.
The research in this domain is ongoing and the interdisciplinary nature
of nanotechnology requires experts from a variety of disciplines working
together to produce viable solutions. While the authors anticipate many
evolutionary and revolutionary developments in this specifi c fi eld, the ulti-
mate market share of nanocomposite steels will depend on continued
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