A new technique was developed bassed on Fourier transform infrared spectroscopy in the multiple internal reflection mode (FTIR-MIR) for measuring in situ water at the polymeric coating/metal interface.Water amount at the interface increased with increasing exposure time in water. The adhesion between polymer and metal surface was weakened when water accumulated at the interface. The ability to prevent water for the epoxy/metal system was much higher than that for the alkyd/metal one. The method was found useful for determining the degradation process of the coating/metal system and its related effecting factors.

The oxidation behavior of two Co-Nb alloys containing 15 and30 Wt.%Nb respectively was studied at 600-800℃ under 1 atm of pure oxygen. The oxidation kinetics followed parabolic law only approximately, whilst, especially at 600℃, the transient rate constant decreased with time. The oxidation rates of the two alloys were faster than that of pure cobalt, but the increment was rather small. The two alloys underwent both external and internal oxidation under all the conditions tested. The external scales were composed of a continuous layer of pure cobalt oxide close to the scale/gas interface, followed by an inner layer containing a complex mixture of two double Co-Nb oxides (CoNb2O6 and Co4Nb2O9) with the basemetal oxide. The region of internal oxidation contained a mixture of cobalt metal, niobium oxides (Na2O5or/and NbO2) and in the outermost region there was a double oxide formed from the Nb-rich metal phase.No niobium depletion region was observed at the alloy/scale interface. The oxidation behavior of these alloys was discussed in terms of the low solubility of niobium in cobalt and the microstructure of the alloys and the oxide scales.

Effect of loading frequency and overloading on corrosion fatigue crack initiation (CFCI) life of notched aluminum alloy LY12CZ specimens in 3.5% NaCI solution were investigated. The frequency had no considerable effect on the CFCI life at the frequency range from 10 Hz to 1 Hz. Tension overloads prolonged the CFCI life, especially in the longer life range. The overloads increased the CFCI threshold value considerably, but had less effect on the CFCI resistance coefficient. The CFCI threshold was in proportion to the strain value at the notch roots caused by overloads. Based on analysis of the experimental results a CFCI life expression, which revealed the quantitative effect of overloading, was put forward. The mechanism of overloading effect was discussed.

The electrochemical behavior of pure zinc in concentrated KOH solution was studied using electrochemical techniques. It was found that the dissolution of zinc was accelerated and the evolution of hydrogen was inhibited in the anodic and cathodic Tafel region respectively with increasing concentration of OH-. Three relaxation processes were observed on EIS at the anodic polarization potentials. The corrosion mechanism of zinc in the alkaline solutions was advanced according to these experimental facts. The relation between the corrosion rate of zinc and the concentration of OH- was obtained by low polarization region curve-fitting technique.

The photoelectrochemical behavior of iron and its susceptibility to pitting in a borate buffer solution ofpH8.4 were studied in the presence and absence of inhibitor PC-604. The aim of this work was to analyze the relationship between character of passivation film and pitting on iron. Pure iron was anodically passivated in the solution for different durations in the presence and absence of the inhibitor, then Cl- was added in, and the change of dark current Id and photocurrent IPh with time was observed. When passivation time passed 24h or the quantity of the inhibitor exceeded 20ppm, pitting could not be initiated.The Eg of the passive film on iron was measured at different inhibitor concentrations and passivatinn durations.Results implied that the Eg data did not vary apparently.But the photocurrent increased with increasing passivation time or inhibitor concentration. It meant the inhibitor did not interfere with the energy level structure of the sc miconductor-passivation film.From transient photocurrent image t he so-called film parameter of passivation film was deterndnd. It was found that at a given passivation time, the film parameter increased with increasing quantity of inhibitor,and at a given concentration of inhibitor,the film parameter increased with increasing passivation time too. It was significant that the role of this inhibitor was to promote efficient passivation. The film parameter was related to the thickness and the compactness of the passive film.

The corrosion properties of the austenitic Fe-30.8Mn-8.2Al alloy in a series of aqueous solutions at PH -0.8 to 15.3 and the corrosion protection mechanism induced by adding Al were studied by anodic polarization technique and by AES/ XPS analysis. The corrosion behaviour of the alloy was compared with that of Fe-30Mn alloy, mild steel, cryogenic 9% Ni steel and 1Cr13 stainless steel. The addition of 30 Wt% Mn into mild steel was very detrimental to its corrosion resistance in aqueous solution. The Fe-30Mn alloy only showed passivation behaviour in NaOH solution while the anodic polarization curves of Fe-30.8Mn-8.2Al alloy exhibited a stable passiwtion region in 1M Na2SO4, 10～50% HNO3 and 10～50%NaOH solutions, but in 10% HCI and 3.5% NaCI solutions, no passivation was observed. The corrosion resistance of Fe-30.8Mn-8.2Al alloy in these aqueous solutions was comparable to that of cryogenic 9% Ni steel but inferior to that of 1Cr13 stainless steel. According to AES/XPS analyses, the outermost surfae layer and the main part of the passive film formed on the Fe-30.8Mn-Al alloy in 1M Na2SO4 solution probably consisted of the hydroxide and a capture of iron, manganess and aluminium oxides.

By comparison of the antitarnishing effects of various agents, the laurylamine was found to be an excellent antitaranishing agent for tinplate. The optimum conditions of treatment were laurylamine 2.5g/L; pH=8.70℃; 10min. The results of XPS and AES analyses showed that on tinplate surface an anticorrosive coordination compound film of laurylamine was formed, and N atoms in laurylamine molecule were coordinated with Sn (II). The relative atomic percent contents (A.C.%) of the film calculated at the constat elemental composition section of the AES profile curves were O 39.0%; Sn 48.7%; N 7.9%; C 4.4%.

By using the technique of glow-discharge ionized surface alloying with an arc source, nickel-chromizing was conducted on the surface of carbon-steel samples with different carbon-content 0.1 wt%, 0.45 wt% and 0.8 wt%, designated as 10 steel, 45 steel and T8 steel, respectively. The microstructure, the elemental concentration distribution and the phases of the surface layer were studied. The corrosion resistance of the diffusion layer in 0.05 mol/L H2SO4 solution was evaluated. The results indicated that the ndcrostructure of Ni-Cr alloying layer on 10 steel was γ-phase only and on 45 and T8 steels were γ-phase based Cr23C6 and Cr7C3. The corrosion resistance of alloying layer on 10,45 steels was comparable with that of 18-8stainless steel. However, nickel-chromizing did not improve corrosion resistance for T8 steel.

Three kinds of Ni-Cr-Al alloys with different amountB of Cr, Al, Co, Ti etc. and trace elements of S and Zr were oxidized isothermally and cyclicly at 1000～1100℃. For the alloy with relatively high amount of Cr(16 wt%) and low amounts of Al(3.5 wt%) and S(≤0.005 wt%), the oxide scale formed after oxidation at steady state stage consisted of a continuous and compact protective Cr2O3 outer layer and dendritic shape Al2O3 internal oxidation zone. The scale adherence demonstrated by cyclic oxidation was fairly good. For the alloy with relatively high amount of Al(5 Wt%) and low amounts of Cr(9 wt%) and S(≤0.005 wt%), the oxide scale consisted mainly of Al2O3,TiO2, Cr2O3 and spinels and the scale adherence was rather poor, but addition of S(0.1 wt%) and Zr(0.1 wt%) into this alloy improved the scale adherence. Small amount of S(≤0.005 Wt%) had no obviously adverse effects on the adherence of Cr2O3 scale. The simultaneous additions of relatively high amounts of S(0.1 Wt%) and Zr(0.1 Wt%) increased the oxidation rate of Al2O3 forming Ni-Cr-Al alloy. The addition of small of Zr(0.1 wt%) could minimize the negative effects of S on the adherence of AlO3 scale.

In accordance with the electrochemical nature of corrosion of metals, it is reasonable to evaluate the effectiveness of rust preventive oil by electrochelnical measurements. In the past,nearly all such measurements were performed with a single large metal electrode coated with oil. In this paper, a new wire beam electrode was proposed. The electrode consisted of 101 mild steel wire sensors embedded in epoxy resin.The corrosion potential of oil-coated electrode and polarization resistance of oil film for each individual wire could be successively measured. It was found that the distributions of corrosion potential on oiled metal and polarization resistallce of oil film were heterogeneous. Corrosion potential on oil-coated metal followed discontinuous binomial distribution,and the polarization resistance of oil film followed lognormal distribution. Addition of oil-soluble inhibitor into the oil extended the area of high corrosion potential and reduced the area of low polarization resistance.

Immersion-wet-dry combined cyclic test was applied to study the synergistic effect of chloride and sulphur-bearing pollutant in atmospheric corrosion of mild steel. The experimental data were analysed and could be formulated by W = K. tn. Morphology of rust was observed by SEM and elemental distribution in rust was analysed by XPS. Results showed that the interaction between Cl- and HSO3 was rather complicated. At the beginning of corrosion, round blisters appeared on the rust and elemental contents inside and outside the blister were different. Synergistic effect of Cl- and HSO3 was significant. As corrosion went cn, the blisters dissapeared, the rust became compact, and the synergistic effect diminished.A mechanism for the synergistic effect was suggested.

Artificial neural network, possessing learning and non-linear character, was applied to study corrosion of mild steel in soil. A neural network typically consists of many simple neurons like processing elements called "cell" or "nodes" that interact with other cells using numerical weighted connection. In this study,a neural network with 6-10-1 structure, namely 6 input nodes, 10 hidden layer nodes, 1 output node, was used. The learning algorithm was BP (Back-Propagation) algorithm. Corrosion tests of mild steel in soil were carried out with orthogonal test method, in which five corrosion factors, namely pH value,Cl-, H2O,SO_4~2- and Fe2+ content, were considered and test data of sixteen groups were obtained. These data were used as sample set to train neural network. The inputs of neural network were the five corrosion factors and test duration, the output of neural network was corrosion rate of steel in soil.The research results showed that soil corrosion rates of mild steel in 24 months could be predicted by the trained artificial neural network, and were basically in agreement with experimental data.

The characteristics of pitting corrosion and corrosion mechanism for type 430 stainless steel in different solutions were studied using the electrochendcal potentiodynamic hysteresis curve technique. Inhibition performance of some inhibitors was also examined. Experimental results showed that increase in concentration of Cl-and solution temperature could accelerate the pitting of 430ss. Oxygen was one of the principal factors to keep passivity of the steel. CO2 was an accelerant for pitting. Na2MoO4 and Na3VO4 could prevent the pitting corrosion in solution containing Cl-and CO2, and they had a synergistic inhibition effect.