The use of nanotechnology to improve the bulk and surface properties of steel for structural applications - Nanotechnology in Eco-efficient Construction - page 96

Table 5.3 Recent research on the utilization of nanotechnology to improve the corrosion resistance of steel

Production
process

Microstructure of
surface or bulk

Novel properties or
phenomenon Reference Steel type Mechanism(s)

Zhang et al.
(2001)

Tool steel
(0.35C-5Cr-
1.5Mo-1V)

Metal vapor
vacuum arc
ion
implantation

Fe 2 Mo, FeMo, Fe 2 MoC,
Mo 2 C, MoC, MoC x
nano-precipitates in
surface layer

Greatly improved
resistance to pitting
corrosion and
corrosion

Nano-(Mo + C) phases
improve the passive
fi lm

Wang and
Li (2003)

304 SS Sandblasting +

annealing

Uniformly distributed
nanocrystalline
grains ( ∼ 20 nm) in
the top surface

Greatly improved
resistance to
corrosion, wear and
corrosive wear

Nanocrystallization and
change in the
dominant wear
mechanics

Kwok et al.
(2006)

316 SS Cavitation +

low-
temperature
annealing

fcc γ -grains (91 nm) Improved resistance to

pitting corrosion and
enhanced ability to
repassivate

High density of GBs as
nucleation sites for
growing a uniform
Cr-rich passive fi lm

Vaynman
et al.
(2002)

NUCu weathering
steel (ASTM
A710B, 0.06% C)

Microalloying +
hot-rolling +
normalizing

Equaxed ferritic
microstructure,
with some dispersed
pearlite bands

Outstanding
mechanical, welding
and anti-corrosion
properties, e.g., TS of
567 MPa, El of 32.2%

Hardening by nano-Cu
precipitation; solid
solution strengthening
by Ni; grain
refi nement by Nb