J.T.Guo
,
S.H. Wang
,
H. Li
,
W.H. Lai and M.H.Tan(Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China Manuscript received 26 August 1996)
金属学报(英文版)
The isothermal oxidation behavior of Ni_3Al containtng 15 at.% Fe and NiAl containing 30 at.% Fe was studied for 100 h at 850, 950, 1050 and 1150℃, respectively. The results show that the oxidation kinetics of the two alloys obey a parabolic law at various temperatures and every parabolic curve possesses two oxidation rate constants. The morphology, microstructure and the chemical composition of the oxide scales were examined using optical metallography, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis. The oxide scale of Ni_3Al containing 15 at.% Fe consists mainly of NiO, NiFe_2O_4, and FeAl_2O_4, and that of NiAl containing 30 at.% Fe consists of Fe_2O_3 and (Fe,Ni)Fe_2O_4, contrasting sharply to the oxide scales of pure Ni_3Al and NiAl which consist of Al_2O_3. The oxide scales on the surfaces of Ni_3Al and NiAl containing Fe are not too dense and not too cohesive to the matrix,so their oxidation resistance is not too good.
关键词:
:oxidation
,
null
,
null
,
null
F.J. Shan
,
C.S. Liu
,
S.H. Wang
,
G.C. Qi
金属学报(英文版)
The corrosion behavior of hot dip galvanized steel
pretreated with bis-[triethoxy-\linebreak\noindent silylpropyl]
tetrasulfide (BTESPT) modified with alumina particles was studied.
The corrosion resistance of the passiving films was evaluated by
Tafel polarization curve and electrochemical impedance spectroscopy.
The films formed on the galvanized steel substrate were
characterized by Fourier transform infrared spectroscopy and energy
dispersive X-ray spectrometry. The surface morphology of the treated
hot dip galvanized steel samples was observed by Field Emission
Scanning Electron Microscope. The results show that the
pretreatments on the basis of silane films modified with nanoalumina
particles have reduced both anodic and cathodic current densities,
and increased total impedance in the measured frequency,
consequently, improving corrosion protection for hot dip galvanized
steel during immersion in NaCl solutions compared to chromate films
and silane films.
关键词:
Bis-sulfursilane
,
null
,
null
,
null
,
null
