13 / 18
Page 49
JET 2018
ISSN: 2319-9873
I n t e r n a t i o n a l C o n f e r e n c e o n
Structural and Civil Engineering
Research
O c t o b e r 0 1 - 0 2 , 2 0 1 8
Am s t e r d a m , N e t h e r l a n d s
Civil Engineering 2018
T
he corrosion characteristics of 304 stainless steel (SS) and titanium (Ti) coatings deposited by the arc thermal spray process
in pH 4 solution were assessed. The Ti-sprayed coating exhibits uniform, less porous and adherent coating morphology
compared to the SS-sprayed coating. The electrochemical study i.e. electrochemical impedance spectroscopy (EIS), revealed that
as exposure periods to solution were increased, the polarization resistance (Rp) decreased and the charge transfer resistance
(Rct) increased owing to corrosion of the metallic surface and simultaneously at the same time the deposition of oxide films/
corrosion on the SS-sprayed surface, while Ti coating transformed unstable oxides into the stable phase. Potentiodynamic
studies confirmed that both sprayed coatings exhibited passive tendency attributed due to the deposition of corrosion products
on SS samples, whereas the Ti-sprayed sample formed passive oxide films. The Ti coating reduced the corrosion rate by more
than six times compared to the SS coating after 312 h of exposure to sulfuric acid (H
2
SO
4
) contaminated water solution, i.e. pH 4.
Scanning electron microscope (SEM) results confirmed the uniform and globular morphology of the passive film on the Ti coating
resulting in reduced corrosion. On the other hand, the corrosion products formed on SS-sprayed coating exhibit micro pores with
a net-like microstructure. X-ray diffraction (XRD) revealed the presence of the composite oxide film on Ti-sprayed samples and
lepidocrocite-γ-FeOOH) on the SS-coated surface. The transformation of TiO and Ti
3
O into TiO
2
(rutile and anatase) and Ti
3
O
5
after
312 h of exposure to H
2
SO
4
acid revealed the improved corrosion resistance properties of Ti-sprayed coating.
m.abdelkader@curtin.edu.myDeposition of coating to protect waste water reservoir
in acidic solution by arc thermal spray process
Mohamed Abdel Kader Ismail
1
, Han Seung Lee
2
and
Jitendra Kumar Singh
2
1
Curtin University, Malaysia
2
Hanyang University, Republic of South Korea
JET 2018 Volume: 7