The electrochemical impedance spectroscopy for stainless steel in simulated cooling water during long time immersion (1~65 days) and short time immersion (in one hour) are measured. The data are fitted using four models, and a suitable model is selected. The fitting results appear that, during the long time immersion period, the charge-transfer resistance R1 is relatively small and the double layer capacity Y01 is relatively large at the beginning of the immersion. When the immersion time increases, the values of R1 and Y01 stabilize. The film resistance R2 increases while the value of Y02 decreases continuously with the immersion, indicating that the passive film is getting thicker and more compact. The value of R2 is about four orders larger than R1 after 8 days' immersion. During the short time immersion period, R1 is close to R2 at 5 min; R1 changes little with time, but R2 increases by one order at 15 min and rises continuously with the immersion.

The wavelet transform theory was applied to investigate the correlation of the characteristics of the free corrosion potential signals and corrosion mechanism in the SSRT (slow strain rate test) of type 304 stainless steel. The group phenomena of type II discontinuity points in the potential signals showed the propagation of stress corrosion cracks

The property of anti-corrosion for titanium alloys in acids, alkalis and hydraulic oil were studied. The results showed that the anti-corrosion sequence for titanium alloys in HCl and H2SO4 was TB8> Ti > TB5, in alkali medium was Ti> TB5> TB8. The property of anti-corrosion in hydraulic oil for TB8 titanium alloy was superior to pure titanium and TB5 Titanium alloy.TB8 titanium alloy was the only alloy which can be used in hydraulic oil.

By means of SEM and TEM examination, metal dusting behaviors have been investigated in CO+H2 syngas for GH600 and another Ni-base supperalloy on which a dense oxide scale can generate. The results showed that local destruction of oxide scale was the beginning of metal dusting, the formation of graphite filaments and pitting below them caused by metal dusting were promoted each other. Self-repairing of the local destructed oxide scale on sample surface in time can restrain occurrence of metal dusting.

In this paper, the anodizing process of newly and environment-friendly for coloring of die-casting magnesium alloy were opened out by orthogonal layout. The anodized film thus formed on Mg alloy is off-white, even, porous, slippery, and this film have favorable coloring effect to obtain manifold colors. At the same time, the anodizing of Mg alloy was studied including the formation process of coating as well as their components, surface micrograph and structures by using the curve of current-time, XRD and SEM.

Propagation process of indentation cracks in silicon oil with an applied electric field for poled PZT-5 ferroelectric ceramics has been investigated. The results showed that indentation cracks could instantaneously propagate in silicon oil with an applied electric field which was higher than critical electric field for instantaneous propagation (Eip=5.25kv/cm) and the lengths of cracks could increase with increasing the time to keep sustained applied electric field. When applied electric field was lower than Eip, the cracks could not propagate, but if keep sustained electric field, delayed propagation might occur. Moreover, the anisotropy of cracks propagation has been measured. The propagation lengths of the cracks parallel to applied electric field direction are shorter than that of perpendicular to applied electric field direction.

Atomic oxygen erosion of spacecraft materials and protection by coatings were studied in the ground-based simulation facilities. The corrosion morphologies and products were characterized by several physical techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Silicon dioxide- potassium silicate organic-inorganic composite coatings due to higher conductivity improved resistance to high temperature and thermal cycling. The results indicated that Kapton is susceptible to AO erosion and undergoes mass loss and surface degradation. SiO2-K2SiO3 coatings have excellent properties for anti-AO effects and good stability for space environment.

An occluded cell, a DIY antimony mini-electrode and a Ag/AgCl mini-electrode were used to investigate the high pH local environment under debonded coating on cathodic protected pipelines. The effects of the exterior protected potential, cathodic protected current density, blocked resistance, environmental temperature and time on formation of high pH local aqueous environment were analyzed according to the result of the simulation tests. A mathematical model of the pH change of local environment was obtained.

The quick analysis system for underground pipeline coating detection has been set up. Defect orientation of the system is made by using the dyadic wavelet transform of ON, instant OFF close interval potential survey (CIPS) potential and the difference of them. It is indicated that the extreme values of detail-coefficients of dyadic wavelet transform will increase with the scale at the damaged points otherwise it will decrease with the scale at the other places. With the product of the third layer detail-coefficients and the product of the third layer smoothed-coefficients of those three curves obtained, the damaged points of the coating could be easily found. To diagnose the coating state of the system the wavelte Kohonen neural network is set up. The front layers of the network are corresponding to multiresolution decompositions, which has the ability of picking up the information. The last layer of the model is corresponding to Kohonen neural network, which has the ability of self-training. The coating state can be quickly diagnosed after the galvanostatic transient response is input to the model. The CIPS is used in pilot detection. Then the damaged points of the coating can be made certain by the defect orientation part of the system. The galvanostatic transient response method is used to detect the coating state of buried pipelines at the damaged point. Then the coating state can be judged by the coating state diagnosis part of the system. The detection result of real pipeline between Dagang and Cangzhou of Tianjin Dagang oil field was satisfactorily.

Corrosion is harmful to the useful lifetime of materials. In general, the phenomena of corrosion are complex models, and have a vast set of responsible factors for its appearance. Therefore, we develop 以 corrosion damage case analyses and expert system with c++ builder and paradox in order to manage corrosion data and analyse corrosion procedures.Corrosion damage case analyses and expert system is composed of atlas of corrosion case history, failure analysis procedures, reports and links to internet. Atlas module can save lots of corrosion cases. The module, composed of general, environment, material, component, test, corrosion and failure, includes 172 fields, and collects 602 cases in China and Europe industry. Procedures module has a main goal of the corrosion case analysis through several procedures already defined. Those procedures have a decision-tree format with different status that allows to obtain a conclusion about the fail cause through its own navigation. Reports and links module can save report results and internet links of corrosion respectively, which are complements to the system.

A consultation and forecast diagnosis system of metal exposed in marine environment has been developed by using the object-oriented programming language, Visual Basic (VB). The system comprises three major modules: database and management system, corrosion prediction and corrosion morphology analysis. In the first part, the common data management function such as data input, data modify, data delete and data refresh are discussed. There are two different method used in the corrosion prediction module, the artificial neural network (ANN) and gray model. Using the ANN method, the corrosion depth of new materials in different marine environment can be predicted. The gray model method can give the corrosion rate of materials in the future. The corrosion morphology images of metallic material in seawater, which are acquired by scanner, are stored in the database. Taking the gray distribution or fractal characters of metallic samples and their corrosion morphology as the knowledge base respectively, the diagnosing system identifying corrosion morphology of metallic material in seawater was established according to the theory of fuzzy pattern recognition. The corrosion morphology of sample can be identified by gray distribution or fractal characters of corrosion images.

The corrosion property of U-0.75Ti uranium alloy that chronically exposed and stored in the typical atmosphere is summarized in this paper. Some main results of sensitivity study for stress corrosion are also summarized. Significant rules that the uranium alloy can chronically preserve very low corrosion rate and obvious atmosphere stress corrosion does not present on the condition that it had been stored chronically are gained. The main characteristic, rule, and environment influence of atmosphere corrosion for uranium alloy on the different condition are discussed in this paper. The characteristic of atmosphere stress corrosion for uranium alloy, the dependence connection with environment condition, and the concerned reason are discussed too.

In this paper, the corrosion rate of mild steel in 0.5mol/L sulphuric acid with and without thiourea were evaluated by the Coulostatic technique, and a novel approach based on NLLS (Non-linear least square) fitting method was persented to get Tafel constant. Different kind of equivalent circuit model such as R(CR(RL)) and R(RC) was discussed, and used to analyze the response to the Coulostatic perturbation. In addition, Electrochemical impedance spectroscopy (EIS) was used to confirm the results from the coulostatic method. The results shows that the Coulostatic technique is not only determined the values of Rp, Cd quickly, but also the Tafel coefficient timely both in the acid solution with and without inhibitor, Therefore the Coulostatic method is useful for a direct and rapid evaluation for corrosion inhibitors, especially for the changeful surface of metal in the acid solutions. Moreover, since the Coulostatic measurement is a very rapid process, so that it is highly convenient to get Rt by analyzing of the R(RC) circuit model, and that indicated that the evaluation process might be made much more simplified.

Corrosion behavior of a candidate connecting tube, a GH132 tube, for supercritical water oxidation（SCWO）system in the environment of disposing the propellant wastewater by SCWO method with the range of temperatures from room temperature to 520℃ and the pressure of 27.2MPa was studied. The morphology of corrosion surface was analyzed using SEM. Intergranular corrosion (IGC) and shallow pitting occurred respectively when the temperature was above 180℃ and 260℃. Severe stress corrosion cracking was found at 280℃ which leaded to leak of the tube after 151h of testing. The maximum decrease in wall thickness of the tube was measured between 340℃ and 370℃,which amounted to 100μm. Within the supercritical temperature range, corrosion of the tube was obviously mitigated and only very shallow pits could be found. Corrosion products were analyzed using EDX and Fourier transfer infrared spectrometry (FTIR). The selective dissolution of elements such as Fe, Cr and Ni and the formation of corresponding oxides and hydroxides accelerated general corrosion within the subcritical temperature range; while, in the supercritical temperature range, corrosion products was protective due to their very low solubilities. Results showed that GH132 tubes could not be used as connecting tubes at subcritical temperatures.

The equipment and technology of the high-power twice atomizing arc spray in steel bridge anti-corrosion is investigated,owing to the shorter service life-span，the more frequency maintenance and the higher maintenance expense for steel bridge tar-paved layer。 The arc spray equipment with the laval primary nozzle and sector compressed second nozzle is designed，the technology with dustless blast、arc spraying zinc and sealed solvent are researched and applied to Wuhan Junshan Yangtse River steel bridge surface ，these coatings for corrosion resistance will extend availability of tar-paved layer above it。