The sputtered nanocrystalline coating of K38G alloy was obtained by means of magnetron sputtering.The corrosion behavior of cast K3 8G alloy and its sputtered nanocrystalline coating with a solid NaCl deposit in dry air or in wet oxygen at 600℃～700℃ was studied.The results indicated that the mass gain of the coating was higher than that of the cast alloy.Nanocrystall ization reduced corrosion resistance of the K38G alloy.The relevant corrosion me chanisms were discussed.

Pitting behavior of anodized aluminum in NaCl solut ion was studied using methods of potentiodynamic polarization and SEM.The result s show that the controlling mechanism for pitting changes with development of th e pit.The early stage and last stage of pit growth are controlled by diffusion,w hile the middle stage is controlled by ohmic action.Once a pit penetrates the an odic film,it preferentially propagates in the aluminum matrix,and hemispherical pit with a film cover above is formed.Only a small pit is present on the film co ver as the diffusion channel for pit development.The growth mechanism of pitting was discussed.

Composition and valences of the elements in the tri phenyl phosphite film formed on the surface of A3 steel were analyzed by means o f XPS and AES.The results show that Fe on the surface of the film is +2 or +3  va lence;that O atom is the coordinate ligand while P and benzene ring do not coord inate;and the composition of the film is polynuclear complex.The mechanism of co ordination of triphenyl phosphite with Fe is suggested.

The cavitation erosion behavior of 20SiMn low alloy steel in both distilled water and 3%NaCl solution was investigated by using a m agnetostrictive-induced cavitation facility.The micrographs of damaged surfaces were observed by scanning electron microscope (SEM).The role of corrosion was an alyzed by the measurements of polarization curve and free-corrosion potential wi th or without cavitation.The results showed that the cavitation shifted free cor rosion potential to the positive direction by 200 mV.The electrochemical corrosi on rate in the presence of cavitation was 53 times higher than that in absence o f cavitation.The maximum cavitation erosion rate in 3%NaCl solution was almost t hree times as fast as that in distilled water,while the morphologies of damaged surfaces in 3%NaCl solution were similar to that in distilled water.The ferrite area,grain boundaries and ferrite-pearlite phase boundaries were preferential si tes for cavitation attack,which attributed to the low hardness of ferrite phase. The mass loss came from the detachment of small pieces in the ferrite area in th e early stage and from the removal of massive chunks by the propagation and conn ection of cracks in both ferrite and pearlite area in the following test period. 

The severe localized corrosion of steels in Yulin a r ea of the South China Sea was analyzed by the use of macroscopic testing of seaw ater corrosion of typical steels induced by marine organisms,testing of major co rrosive bacteria and FeS in the rust layer on steel specimens and testing of cal cium deposits in the rust layer on steel specimens.The results reveal that the m arine organisms grow vigorously all year round due to rather high temperature of seawater in this area and result in uneven fouling to the surface of steel speci mens,which increases the electrochemical heterogeneity of the surface of steel s pecimens,the amounts of several aerobic bacteria and anaerobic SRB in the rust l ayer on steel specimens exposed in Yulin testing station are several times to th ree orders of magnitude larger than those on steel specimens exposed in Qingdao testing station,where the temperature of seawater is lower,and show collective d istribution;the content of FeS in the corrosion product on steel specimens expo sed in Yulin testing station is 0.1 times to twice higher than that of steel spe cimens exposed in Qingdao testing station.High Content of FeS and severe localiz ed corrosion induced by bacteria are two important factors for aggravation of lo calized corrosion of steels in Yulin area of the South China Sea.

The changes of the surface morphology of an extrude d composite of Al18B4O33 w/pure Al during the early stages of corr osion by 3.5%NaCl solution were observed by atomic force microscopy.The features of corrosion of the composite samples with different normal angles to the extru sion orientation in 3.5%NaCl solution were studied.The results indicated that co rrosion occurred preferentially at the interface between whisker and matrix.Pitt ing occurred frequently at the end of whisker firstly and propagated along the i nterface between whisker and matrix.The number and size of pits on the surfaces of the extruded Al18B4O33 w/pure Al composite samples are differen t due to the sample surfaces with various angles to the extrusion orientation of the bulk composite.

Various concepts developed in the framework of wave let transforms have been adapted to the analysis of electrochemical noise measur ements (ENM).These new mathematic methods are proposed as an alternative tool to overcome the limitations of FFT in the analysis of ENM.In this paper,a new desc ription method of electrochemical noise (EN)using feature vector subbands' energ y obtained by wavelet packets decomposition was described.Both PSD obtained by FFT method and subbands' energy were applied to study the EN signals during high -purity aluminum corrosion in Cl- solution under potentiostatic conditions.Fro m PSD characteristics,it was found that if the immersion time in Cl- solution was prolonged,the activity life of pit nucleus shortened,but the passivation tim e of pit nucleus lengthened,and SO2-4 only influenced the frequency of p it nucleus appeared.Compared with FFT method,subbands' energy feature vector can describe the high frequency “fingerprint” characteristics of EN signals,which can offer an enhanced ability to categorize different corrosion systems,differe nt corrosion types and different corrosion intensity. 

The atmospheric corrosion data of three kinds of pr e-corroded carbon steels at Beijing and Jiangjin exposure sites are studied.The characterizations of the corrosion products formed on the samples at Beijing exp osure site have been studied by FTIR and XRD.The results show that the corrosion rates of carbon steels at Jiangjin site are much greater than that at Beijing s ite under the same condition; the pre-corroded means have made some small differ ences to the kinetics behaviors of three kinds of carbon steels，but they have n o difference to the corrosion phases of carbon steels after exposure over one ye ar.The effects of different pre-corroded means on the atmospheric corrosion of c arbon steels are analyzed.

In this paper Mannich reaction between higher amide 、ketone and phosphorus(Ⅲ)chloride was used to synthesize two kinds of amide al kyl phosphate compounds and weight-loss method、permanent potential scan method was used to test their corrosion inhibition in the environment of oil field inj ection water.Their biological activity has also been investigated.They have very strong sterilization performance.Also the paper has analysed their adsorption f orm and corrosion inhibition mechanism sample surface.

Environmental concerns drive market to find environ ment-friendly solder to replace the lead-bearing solder for microelectronic join ing.In this paper,the corrosion behavior of Sn-37Pb and SnZn based lead-free sol ders(including Sn-9Zn,Sn-9Zn-0.25RE) has been investigated.Mass loss evaluati on,observation of corrosion morphology by scanning electron microscope(SEM) and electrochemical testing has been conducted on.The corrosion experiments were un dertaken in tap water(room temperature),tap water(70℃),in air with high humid ity at high temperature(70℃) and in 3% NaCl solution at room temperature separ ately.The results reveal that:SnPb solder was corroded uniformly under the all c orrosion conditions mentioned in the paper.The corrosion products are likely to peeling off from the matrix for their weak joining.SnZn based solder is characte ristics with chosen corrosion of zinc for the low standard potential of zinc,res ulting in pitting of the alloy.The corrosion mechanism of this zinc-bearing sold er is a mixing of pitting and entire corrosion,leading to fast corrosion rate.Mi nimal rare-earth elements in SnZnRE solder improve the compactness of the micros tructure of SnZn alloy and its corrosion products,resulting in the slow corrosio n rate and stronger corrosion-resistance of SnZnRE solder.Based on the above exp eriments,Sn-Zn based solder will be expected to replace the SnPb solder when its competitive properties meet the required touchstones.

The corrosion rates of 17 steels were gray clustering analyzed.The kinds of steel were as objective,test station as cl ustering index,high,middle and low as clustering gray number，the critical value of white function confirmed by the mean and standard deviation of the rates of all steels at same test station.Normalized clustering coefficients were obtained .The weathering performances of low alloys were judged with normalized clusterin g coefficient.The effects of chemical composition on the weathering performance were analyzed.It was proved that this method can be used in discovery of the sim ilar experimental data.

Considering the urgent need for methods of resistan ce to wet H2S stress corrosion cracking (SSC) during petrochemical production ,this paper,with a view to isolate substrate from the corrosives,introduced arc spraying metallic coatings as a method resistant to SSC.Five coating products i ncluding both coatings of Al series and coatings of Fe-Cr series,which are made from self-developed cored wires,were designed.A series of tests where variables such as bond adhesion tests,hydrogen permeation tests,electrochemical tests and stress corrosion tests were carried out in order to check the performance of SSC .The test results of all kinds of coatings were compared with each other,a kind of most protective coating termed ZH4 containing Al+Al2O3+RE was obtained.I n addition,the protective mechanism of coatings resistance to SSC was discussed. 

The topography,geomorphy and climate in western are a in our country are complex and multivariate.According to climatic factors and environmental conditions,there are approximately four types of typical atmospher ic environment,namely acid rain environment,desert environment,plateau environme nt and tropical rainforest environment.The atmospheric corrosion degrees of all types of environment are different,as well as are the corrosion failure features of materials under different environment conditions.The acid rain atmospheric e nvironment aggravates the corrosion failure of metals,protective coatings on met als and building materials,etc.Although the climate is dry and there is little r ain in the desert atmospheric environment,owning to the high salt content in air sediment,the corrosion failure of copper,zinc,aluminum,stainless steel and meta l coatings in Takelamagan area located in Talimu basin is severer than that in e astern moist hot or semi-moist hot city environment.Under plateau environment condition,the significant feature is that macromolecular materials will fail rap idly.The feature of tropical rainforest atmospheric environment is mainly that o ptical instrument,leather,fabric and timber will be severely moulded.