The principle of material selection for the wet processing of phosphoric acid production was introduced in terms of the features of the wet processing as well as the performance of the stainless steels developed for phosphoric acid production. The characteristics of various stainless steels, such as their chemical composition, corrosion resistance, mechanical properties and processing property for manufacturing etc. were given as an easy reference for the users. Finally the development trend of stainless steels in this industrial sector was also discussed.

Radiation field intensity in the primary coolant system of water-cooled reactors could be reduced by chemical decontamination process. Thus, the recent research progresses of the decontamination process and its corrosion effect on structural materials of the primary coolant systems were summarized in this paper.

The galvanic corrosion behavior between 45 steel and B10 Cu-Ni alloy by cyclic immersion in seawater was investigated in comparison with that by full immersion. The results showed that the galvanic potential moved negatively and then stabilized at about -725 mV during full immersion in seawater, while the galvanic current decreased with time and stabilized below 10 μA finally. By cyclic immersion, the couple potential shifted positively with wet/dry cycling and reached a value of about -650 mV after 3 cycles; the couple current decreased with time and stabilized at about 20 μA. The mass-loss measurement proved that the galvanic corrosion rate of 45 steel and the galvanic effect by cyclic immersion was greater than those by full immersion, which could be related to the change of the sample surface and the depolarization effect during the dry periods of the cycles.

The electrochemical corrosion behavior of alloy 690 in environments of ethanolamine (ETA) and all volatile treatment (AVT) water chemistry was studied by means of Tafel polarization curves and electrochemical impedance spectroscopy(EIS) with a particular emphasis on the effect of pH, temperature, Cl^- and SO^42- on the electrochemical performance of alloy 690. The results showed that under the two different water chemistry conditions, the increase of pH value would enhance the corrosion resistance of the alloy while the elevation of the temperature and the addition Cl^- and SO^42- would accelerate the corrosion of alloy 690. Under the same conditions, ETA water chemistry environment had a better compatibility with alloy 690 and ETA exhibited better inhibition efficiency than NH³.

The corrosion behavior of a galvanized steel after passivation treatment in NaCl solution was investigated by measurements of corrosion potential and electrochemical impedance spectra (EIS). The results indicated that there were three stages for corrosion of the galvanized steel in NaCl solution i.e. dissolving of the passive film, anodic corrosion of zinc plating and then corrosion of the substrate steel. During the initial stage of immersion in NaCl solution, the behavior of the galvanized steel after passivation was affected by the content of Cl^-, the higher of the Cl^- content, the much serious was the corrosion of the galvanized steel. With the extension of the immersion time, the corrosion resistance of the galvanized steel firstly decreased and then increased with the increasing Cl^- content. The galvanized steel after passivation showed the poorest corrosion resistance in 5% NaCl solution.

The corrosion behavior of Q235 mild steel in 0.25 mol/L H²SO⁴ solution with the addition of bis-benzimidazole as an inhibitor was investigated by mass loss, electrochemical methods and electron scanning microscopy (SEM). The results showed the compound exhibited excellent corrosion inhibition performance, and the inhibition efficiency increased with the increase of the compound concentration. The compound acted as a mixed-type inhibitor by suppressing both anodic dissolution and cathodic hydrogen reduction processes simultaneously. The adsorption of the compound on mild steel surface followed the Langmuir isotherm.

The corrosion behavior of 409 ferritic stainless steel in two kinds of condensate solution with or without Cl^- was investigated to analyze the corrosion effect of Cl^- in condensate solution by applying cyclic oxidation-condensate evaporation method, which simulated the corrosive environment inside automotive exhaust mufflers. The results of electrochemical tests in both solutions showed that passive films formed first after oxidation at 250 ℃, then was deteriorated during the cyclic oxidation and evaporation process, forming pitting due to localized corrosion. However, the presence of Cl^- in the solution retarded the formation of protective oxide film in the pits, and further promoted the growth of pitting.

The nanocomposite Ni/WC-Co coating was prepared by DC electrodeposition of Ni with WC-Co nano-particles on brass. The phase constituent and surface morphology of the coating were characterized by XRD and SEM. The microhardness of the coating was measured by using microhardness tester. The corrosion behavior of the coating in 3.5% NaCl solution was investigated by using electrochemical methods. Compared to pure nanocrystalline Ni coating, the average grain size of Ni in nanocomposite Ni/WC-Co coating was slightly finer, which was about 18 nm; the microhardness of the nanocomposite coating was 58% higher, reaching about HV 500. The corrosion current density and corrosion potential of the nanocomposite coating in 3.5% NaCl solution were 8.369 μA/cm² and -0.265 V, respectively, as a contrast with those of 1.467 μA/cm² and -0.179 V for pure nanocrytalline Ni coating. It concluded that the microhardness of the nanocomposite coating was enhanced significantly, but the corrosion resistance in 3.5% NaCl solution decreased as compared with pure nanocrystalline Ni coating.

The electrochemical behavior of LF21 aluminum alloy, as a major base materials used in electric power system, in 5% NaCl solution were investigated by Tafel linear extrapolation method, electrochemical impedance spectroscopy technique and neutral salt spray test. The surface morphology and chemical composition of the corrosion product of the alloy were examined by scanning electron microscope and energy dispersive spectrometer, respectively. The results showed that LF21 aluminum alloy exhibited poor anti-corrosion performance in 5%NaCl solution. When the temperature of solution increased, the corrosion potential of LF21 aluminum alloy shifted negatively, and the corrosion current density increased. Meanwhile, the capacitive resistance and film capacity decreased with the increasing of the solution temperature, implying that the protection film on the surface of material was deteriorated to some extent. The major corrosion form of LF21 aluminum alloy in NaCl solution was pitting corrosion, and the corrosion resulted in much deeper corrosion pits.

The synergistic inhibition effect of sodium gluconate and sodium benzoate with Zn²⁺and La³⁺ respectively on cast iron Z30 in 3.5% NaCl solution was studied by means of mass loss method. The results showed that the complex of sodium gluconate and sodium benzoate with additives of Zn²⁺ and La³⁺exhibited good synergistic inhibition effect and the inhibition efficiencies reach 92.5%and 95.3% when the concentration of sodium gluconate and sodium benzoate both was 250 mg/L, while the concentrations of Zn²⁺ were 2 mmol/L and 3 mmol/L, respectively. On the other hand, an inhibition efficiency of 86.7% was achieved for the complex with 0.5 mmol/L La³⁺.

Rosinyl imidazolium was synthesized using rosin and diethylenetriamine, and then was modified to produce water soluble quaternary ammonium salt by sodium monochloroacetate. The corrosion inhibition effect of the quaternary ammonium salt was investigated by mass loss and electrochemical methods for mild steel in CO²-saturated 3%NaCl solution at 60 ℃. The results showed that the water soluble rosinyl imidazolium quaternary ammonium salt showed excellent corrosion inhibition for mild steel, with an inhibition efficiency above 90% for a dose of 150 mg/L. The inhibitor mainly prohibited the anodic process of corrosion and the inhibition effect obeyed the Langmuir adsorption isothermal equation. The inhibitor could be adsorbed on the surface of steel by chemical adsorption.

The morphology and composition of the anodic film of aluminum, which was sealed in cerium salt solution by pulse power, have been characterized by SEM and XPS. The results showed that after 2 h treatment, the anodic film was completely sealed and consisted of mixture of trivalence and quadrivalence Ce oxide and Ce hydroxide.

Stress corrosion cracking (SCC) of X100 pipeline steel in simulated solutions of acid soil environment located at Yingtan area was investigated by slow strain rate test (SSRT), SEM observation of fracture surfaces and potentiodynamic polarization curves. The results showed that SCC exhibited a transgranular cracking mode. The applied polarization potential played an important role in facilitating SCC. Within anodic potential range, the X100 pipeline steel was controlled by anode process and was insensitive to SCC, but intergranular corrosion appeared. When X100 pipeline steel was controlled by combined anodic and cathodic processes, the stress corrosion sensitivity was low, and the crack grew slowly. But as the applied cathode potential lowered further to a range of only controlled by the cathodic process, hydrogen embrittlement mechanism played the major role and the cracks developed quickly.

Corrosion protection performance of maleic anhydride copolymer water-borne polyurethane coatings incorporated with pigments SAPP and SRPP, which are the so called second-generation nontoxic anti-corrosion pigments, was investigated by salt spray test, electrochemical impedance spectroscopy (EIS) measurement and immersion test. The results showed that the incorporation of SAPP and SRPP to the coating led to a remarkable improvement on its anticorrosive properties, and the corrosion resistance of SRPP was superior to that of SAPP.

A new technology of full-bright electroless Ni-Cu-P alloy plating for steel pieces was investigated by adding copper sulfate and brightener into an acidic electroless plating Ni-Cu-P solution. The effect of main components of electrolytes and parameters of process on the performance of the Ni-Cu-P alloy deposit was examined. The results indicated that the obtained electroless Ni-Cu-P alloy deposit was of good compactness, high brightness and decorativeness. The corrosion resistance and wear resistance of the deposit and the stability of the plating solution were all superior to those of acidic electroless Ni-P alloy plating.