Two ultrafine-grained Ni-based superalloys with or without the addition of micron Cr₂O₃ particles are prepared by mechanical alloying (MA) and spark plasma sintering (SPS). The microstructure and high temperature oxidation behavior of these two alloys are investigated. Results indicate that the Cr₂O₃ particles are completely transformed into Al₂O₃ after sintering at 1200 ℃. Owing to the high speed of sintering by SPS and the pinning effect of oxide dispersoids, the grain growth of the alloy was effectively inhibited during sintering, which makes the ODS alloy exhibits ultrafine grain structure with an average grain size of 0.98 μm, while the same alloy without addition of Cr₂O₃ particles (denoted as blank contrast alloy) has a larger average grain size of 1.54 μm. The ODS alloy has better oxidation resistance with lower oxidation rate at 900 ℃. A continuous and dense layer of α-Al₂O₃ scale has immediately formed on the surface of ODS alloy, thus effectively prevents the outward diffusion of Ti and Cr and the formation of less protective TiO₂ and NiCr₂O₄. For the blank contrast alloy, a multilayered scale with Al₂O₃ as the inner layer, TiO₂ and Cr₂O₃ as the middle layer and NiCr₂O₄ as the outer layer could formed on the surface, and its oxidation rate is 1.66×10^-7 mg²·cm^-4·s^-1 in the initial stage, which is more than twice as much as that of the ODS alloy.

Propylene glycol has many merits, such as high boiling point (184.8 ℃), high flash point (107.2 ℃), nontoxicity and can be miscible with water and ethanol. These make propylene glycol be an environment-friendly and safe solvent that may be a promising alternative to commonly used ethanol or methanol solvent in silanization solution. In this paper, the kinetics of hydrolytie polycondensation of tetramethoxysilane in four environments with different water content and pH value with the addition of propylene glycol were systematically investigated by means of proton nuclear magnetic resonance (¹H NMR) and MALDI-TOF mass spectrometry. The results showed that the addition of propylene glycol remarkably promoted the rate of hydrolytie polycondensation of silane in low water content or neutral environment, however the above effect caused by propylene glycol can be ignored due to the high rates of hydrolytie polycondensation of silane itself when the water content is higher or the pH of solution is relatively lower.

B30 Cu-Ni alloy was widely used in the manufacture of marine condenser because of its excellent characteristics, but there was still a serious pitting problem in the actual working conditions. Because the corrosion resistance of B30 Cu-Ni alloy was related to the protective film formed on its surface, therefore, it is worthy to clarify the influence factors for the passivation film formation of B30 Cu-Ni alloy in an artificial seawater. Hence this article aims to examine the effect of dissolved oxygen and flow rate of the seawater on the film formation by means of electrochemical measurement and surface observation methods, so that the optimal conditions for the film formation were determined. The results showed that the protective property of the surface film increased with the increase of dissolved oxygen concentration (DO) in the seawater. In the range of flow rate of 0-2.0 m/s, with the increase of flow rate, the quality of the formed film first became better and then worse. The film formed on B30 Cu-Ni alloy was the most compact and complete when the flow rate was about 0.8 m/s. Dissolved oxygen affected the quality of film formation by varying the reaction process of film formation. The flow velocity affected the film formation by changing the dissolved oxygen concentration around the sample and producing a scouring effect. The increase of dissolved oxygen concentration was conducive to the formation of the film, while the scouring effect of seawater would destroy the formed film.

Nanocrystallization can increase the diffusion rate of alloying elements, such as Cr, Al, and then improve the high-temperature oxidation resistance of metallic alloys due to the presence of high-volume fraction of grain boundaries. Up to now, the studies on the effect of nano-structure on the oxidation behavior of alloys mainly focus on the oxidation kinetics and the structure of oxide scale at steady stage. The microstructure of oxide scale formed on nano-structured alloys during oxidation, especially at the initial stage, is lack of characterization. At the same time, nano-structured alloys are far away from thermodynamic equilibrium state, which inevitably result in the grain coarsening during oxidation process. Therefore, it is necessary to characterize the microstructure of oxide scale on nano-structured alloys to understand the relationship between grain coarsening of alloy and the formation of oxide scale on its surface. In this study, the oxidation behavior of coarse-grained (CG) and nanocrystalline (NC) Ni-12Cr alloys (mass fraction in nominal chemical composition) at 800 ℃ in air were studied. The NC alloy was prepared by severe plastic deformation, and the average grain size is around 42 nm. Focused ion beam (FIB) microscope and scanning transmission electron microscope (STEM) were used to characterize the microstructure and composition distribution of the scale. The results demonstrate that a two-layered scale, external NiO and internal Cr-rich layer, is formed on both of CG and NC alloys after oxidation for 25 s. The scale on CG alloy develops into a multilayered structure, which includes NiO/(NiO+NiCr₂O₄)/porous Cr₂O₃/internal oxidation zone after oxidation for 10 min, while the Cr-rich layer on NC alloy crystallizes and forms a protective Cr₂O₃ scale after oxidation for 2 min. The oxidation kinetics of NC alloy consists of two stages, both of which follow the parabolic law. The parabolic rate constants of the two stages are 1.76×10^-13 cm²·s^-1 (within 1 h) and 1.58×10^-14 cm²·s^-1 (1-109 h) respectively, both of which are about 3-4 orders of magnitude lower than that of CG alloy. The study on grain growth kinetics of alloy indicates that the protective chromia scale forms before the significant coarsening of nano-grain. According to Wagner theory with the effective diffusion coefficient, the critical grain size for Ni-12Cr alloy to change from internal oxidation to external oxidation is about 94 nm at 800 ℃.

By taking marine Pseudoalteromonas lipolytica (P. lipolytica) wild type strain (WT) and the genetically engineered P. lipolytica mutant strain with hmgA gene deletion (∆hmgA) as model strains, the influence of marine bacteria secreting pyomelanin on the corrosion behavior of 316L stainless steel in marine bacteria culture solutions was studied via electrochemical measurements, scanning electron microscopy (SEM), laser confocal microscopy (CLSM) and X-ray diffraction (XRD). It was proved that WT strain did not cause corrosion of the stainless steel, correspondingly a compact passivation film may form on the steel surface in the medium containing WT. While the ∆hmgA strain will secrete pyomelanin and induce formation of mineralization sites on the stainless-steel surface, thus destroying the formed passivation film and further causing serious pitting corrosion. In bacterial pyomelanin solution, the stainless steel will also be suffered from pitting corrosion, however, a rather intact passivation film can still be formed on the steel surface due to that no bacteria may be involved to the process. In general, this study revealed that the corrosion mechanism of stainless steel in the environments containing pigmented bacteria and the influence of pyomelanin on passivation film formation and pitting development.

The corrosion behavior of super 13Cr stainless steel subjected to different heat treatment processes in CO₂-saturated oilfield formation water was assessed by means of metallographic microscope, XRD, electrochemical experiment and slow strain rate tensile method. The results showed that reversed austenite appeared in the super 13Cr SS after tempering at 620 ℃. A secondary tempering treatment could result in the increment of the amount of reversed austenite. There exists a passivation interval on polarization curves in CO₂-saturated oilfield formation solution for all the super 13Cr SSs after being subjected to different heat treatments. The tempering process could result in decrease in the corrosion resistance of super 13Cr SS, in the contrast, a secondary tempering could result in an enhancing effect. The corrosion resistance of super 13Cr SS was related to the content of reversed austenite. The oil-quenched 13Cr SS had the highest SCC sensitivity. The SCC mechanism of the quenched 13Cr SS, as well as the 13Cr SSs tempered at 550 and 690 ℃, respectively were all hydrogen induced cracking. The SCC sensitivity of 13Cr SSs after subjected to 620 ℃-tempering and 650 ℃+620 ℃ double-tempering, decreased due to the presence of reversed austenite, accordingly, the cracking mechanism was mixed fracture.

At present, TiO₂ nanotubes are mainly prepared in single fluorinated electrolyte by secondary anodization. Herewith TiO₂ nanotube arrays were prepared in three electrolytes of different fluoride ions (F^-, BF₄^-, F^--BF₄^-) by secondary anodization, aiming to figure out how the preparation processes affect the photogenerated cathodic performance of the prepared TiO₂ nanotubes as photoanodes. The morphology, structure, light response ability and photogenerated carrier separation efficiency of the three nanotubes were comparatively examined by means of SEM, XRD, UV-vis DRS and PL, while the photoelectrochemical properties of the three samples were tested in the condition of open and closed visible light. The results showed that TiO₂ nanotube arrays prepared in glycol composite electrolyte containing NH₄F, NH₄BF₄ and H₂O presented much regular structure, stronger light absorption, higher photogenerated carrier separation efficiency and better photogenerated cathodic protection for 304 stainless steels rather than those prepared in traditional electrolyte of single fluoride salt.

The increase of Mo content can improve the corrosion resistance of austenitic stainless steel. In this paper, the corrosion behavior of four austenitic stainless steels 316L, 904L, S31254 and S31254-B with different Mo content in 10%NaCl solution has been comparatively examined. The effect of solution treatment and low temperature aging treatment on the corrosion resistance of steels was compared. The microstructure, corrosion resistance and surface corrosion morphology of the four stainless steels were characterized by means of scanning electron microscope, electrochemical scanning polarization curves and electrochemical impedance spectroscope. The results show that the four stainless steels present different corrosion performance in 10%NaCl solution, their corrosion resistance can be ranked as follows: low temperature aging state>solid solution state for all steels; whilst S31254-B>S31254>904L>316L. The increase of Mo content, the addition of B and the aging treatment at low temperature can improve the corrosion resistance of the steels. Meanwhile, B can promote the formation of Cr- and Mo-rich oxides in the outer layer of passivation film, which makes the surface of passivation film much compact, and the lean-Cr and -Mo regions at grain boundaries can be slowed down, therewith the corrosion resistance of the steels can be improved significantly.

The activation- and passivation-behavior of Q235 low carbon steel was investigated by means of mass loss measurement, electrochemical measurements, and surface characterization techniques. Results show that in NaHCO₃ solutions, the corrosion behavior of low carbon steel in the initial stage was quite different from that in the last stage, especially in the solutions of low NaHCO₃ concentrations, which may be related to the variation of corrosion products formed on the surface of the steel. HCO₃^- could influence the corrosion kinetics of Q235 steel in naturally aerated conditions. When the content of HCO₃^- was limited, the anodic/cathodic reactions were determined by charge transfer process, while by diffusion process in solutions with high concentrations of HCO₃^-. The corrosion rate of Q235 steel was affected by the morphology and compactness of corrosion products in NaHCO₃ solutions with different HCO₃^- concentrations. High concentration of HCO₃^- was beneficial to the formation of compact corrosion products, which could diminish the corrosion rate of low carbon steel.

The effect of pH value on the electrochemical corrosion and stress corrosion of X100 pipeline steel in CO₃^2-/HCO₃^- containing solutions were studied by means of measurements of potentiodynamic polarization curve, AC impedance spectrum and Mott-Schottky curve, as well as slow strain rate tensile test. The results showed that with the increasing pH value, the thickness and compactness of the formed passive film and the pitting potential of X100 pipeline steel increase, while its SCC sensitivity reduces to certain extent.

The corrosion characteristics of J55 steel in an artificial solution charged with 1.0 MPa CO₂, 0.3 MPa H₂S and 1.0 MPa CO₂+0.3 MPa H₂S respectively, in a high-temperature and high-pressure autoclave were studied via immersion corrosion test and electrochemical test, while the tested steels were characterized by means of XRD, SEM and EDS. The results show that in solutions charged with H₂S and CO₂+H₂S the J55 steel presents the similar corrosion rate, and in the solution charged with CO₂ the J55 steel exhibits the highest corrosion rate, accordingly, the formed corrosion product is the loose FeCO₃ with low coverage. Comparatively, the corrosion product formed in the H₂S charged solution is compact FeS, and the FeS generated in the CO₂+H₂S charged electrolyte is thinner and less compact. The in-situ electrochemical test at high temperature and high pressure showed that the corrosion process of J55 steel in the plain solution without charge of corrosive gas was controlled by the cathodic reaction. The charging H₂S could result in the transformation of the controlled step from the cathodic reaction into anodic reaction, correspondingly, the corrosion potential increased significantly. The charging CO₂ could strengthen the cathodic reaction control effect and reduce the corrosion potential. When CO₂ and H₂S coexisted, CO₂ could promote the increase of the formation potential of FeS film. EIS diagram shows that the polarization resistance of J55 steel is the largest in the plain solution without corrosive gas, while the polarization resistance is the smallest in the solution charged with CO₂ only, and two time-constants of high frequency capacitive arc and low frequency capacitive arc emerged for the J55 steel only in the H₂S charged solution.

The corrosion inhibition performance of imidazolidyl ionic liquids with different halogen anions (such as 1-vinyl-3-butyl-imidazolium chloride salt, [VBIM]Cl, 1-vinyl-3-butylimidazolium bromide, [VBIM]Br, and 1-vinyl-3-butylimidazolium iodide, [VBIM]I) on X70 steel in 0.5 mol/L H₂SO₄ solution was comparatively assessed by electrochemical impedance spectroscopy, polarization curve measurement, scanning electron microscopy and atomic force microscopy. The results indicated that they were all the mixed corrosion inhibitor and could effectively inhibit the corrosion of X70 steel in 0.5 mol/L H₂SO₄ solution. With the increase of the concentration of corrosion inhibitors, the corrosion inhibition efficiency increases gradually. And the inhibition efficiency reached the maximum by the concentration of 5 mmol/L. The corrosion inhibition efficiency of the inhibitors may be ranked as the follows: [VBIM]I is higher than [VBIM]Cl and [VBIM]Br in turn, which is mainly due to the specific adsorption of I^-. The inhibition mechanism may be described as that there is a synergistic inhibition effect between the cation and anion of the studied ionic liquid corrosion inhibitors. In other words, both the anions and cations of ionic liquid can participate in the corrosion inhibition process of metal.

A corrosion survey was made for the subway rails at Wuhan city of Central China, focusing especially on the corrosion related environments in tunnels of subway stations in service or under construction. The chemical composition of the collected water samples, the microstructure and phase constituents of corrosion products on subway rails were examined. The results show that according to the difference in the corrosion degree of subway rails and the quality of relevant waters collected from various tunnels, the corrosion environments encountered for the subway rails can be divided into four categories: humid atmosphere, sewage immersion, cement mortar as cover, and stray current. As the subway rails in service or storage in the above four types of environments, the corrosion degree of the rails is different: in the humid atmosphere, the formed corrosion products on rails (in service) are compact and stable with protectiveness to certain extent; in the condition of sewage soaking and cement mortar as cover, the rails (under construction) experienced local bubbled corrosion and uniform corrosion with the participation of Cl^-; while the stray current induced corrosion (in use) can directly cause the damage of the rail bottom, which is the fastest and the most severe corrosion of the subway rails, what we've seen up to now. In view of the corrosion of rails in different environments, the corresponding protection measures are also put forward.

A protective insulation coating for non-oriented electrical steel plate was developed with phosphate-based film forming agent, rare earth passivator and silane coupling agent as raw material. The microstructure, composition, electrochemical performance and resistance to salt spray testing of the coatings with different additives were characterized and assessed. The results show that adding rare earth passivator to the film forming agent can effectively fill the pores on the surface of coating. While the addition of silane coupling agent may be beneficial to the dispersive distribution the rare earth salt precipitates, thereby, resulting in a more uniform surface without obvious defects of the composite coating. The electrochemical test results show that the composite coating presents lower corrosion current density and larger polarization resistance. Taking the salt spray test results into consideration, it is evident that the composite coating has excellent corrosion resistance. In addition, the properties of the composite coating, such as interlayer resistance, adhesion, and pencil hardness are all higher than the requirements of the relevant industrial standards.

The stray current induced corrosion is a common form of corrosion that occurs in the concrete structures of electrified traction systems, which becomes more and more serious with the increasing service life. Hence, in order to clarify the spatial distribution of reinforcement corrosion in the conductive matrix like concrete in the presence of stray current, the corrosion features of reinforcement in a transparent imitated concrete was assessed experimentally, meanwhile the finite element simulation of the applied electric field was also carried out. A finite element model of three steel bars embedded in a rectangular matrix was established to carry out numerical simulation studies, the corrosion state of the steel bars and the stray current electric field of the matrix were discussed in terms of the relevant parameters. Meanwhile, the corrosion experiment of the test piece with the same size as the numerical model was carried out, and the obtained corrosion rate of the steel bars was compared with the simulation result. The results show that the corrosion rate of reinforcements and the electric field distribution in the matrix in the presence of stray current can be simulated by taking the polarization reaction with Maxwell electric field into account. In addition, the distribution of corrosion amount can be evaluated qualitatively and quantitatively by optical observation and the 3D laser scanning of the test piece with transparent matrix.

These results show that the passivation films formed on 316L stainless steel in air and phosphoric acid solution have a double-layered structure. The inner layer mainly contained Cr₂O₃. The outer layer of passive film formed in air was composed of Fe oxides and hydroxides. The outer layer of the passive film formed in phosphoric acid solutions was Fe oxide and phosphate. When the phosphoric acid concentration was less than 1 mol/L, the passive film of 316L stainless steel is less damaged, maintaining good corrosion resistance. However, as corrosion time extended, the passivation film would change from compact to loose. When the phosphoric acid concentration was greater than 1 mol/L, the passive film was seriously damaged, becoming thin and loosened, so that the corrosion resistance was obviously reduced. The formation of insoluble corrosion products relatively slows down the process of passive film damage.

The corrosion behavior of Q690 bainitic bridge steel and its welded joints in a simulated rural atmospheric environment were studied via cyclically wetting and drying method, electrochemical testing, X-ray diffraction (XRD), field emission electron probe micro analysis (FE-EPMA) and other modern surface analysis techniques. The results showed that the corrosion processes of Q690 steel and its welded joint may be differentiated as two stages, namely, the accelerated corrosion stage with n>1 and the deceleration corrosion stage with n<1. In the early stage of corrosion, owing to the obvious microstructure differences among BM (base metal), HAZ (heat affected zone) and WZ (weld zone) of Q690 steel welded joint, galvanic corrosion could emerge, i.e., WZ and HAZ act as anode and BM as cathode, resulting in worse corrosion resistance of the former two, in the contrast to BM. In the later stage of corrosion, as the stable rust layer formed, the difference in corrosion resistance between Q690 steel and welded joints was reduced.

The corrosion behavior of Al-3.0Mg-xRE/Fe alloys in 3.5%NaCl solution in the presence of magnetic field of different intensities was studied by means of electrochemical workstation, and scanning electron microscope (SEM) with energy disperse spectroscopy (EDS). The results indicated that the applied magnetic field could enhance the corrosion potential and pitting corrosion potential, and reduce the corrosion current density of Al-3.0Mg-xRE/Fe alloys. At the same time, the amount and size of the formed pits in the presence of magnetic field were lower than those in the absence of magnetic field. Magnetic field can reduce the corrosion- and pitting-sensitivity, and the corrosion rate of Al-3.0Mg-xRE/Fe alloys. With the increase of magnetic field intensity, the inhibition effect of magnetic field is enhanced.

In view of the increasingly serious corrosion problem of the heating surface of structural materials for waste power plant boilers, the corrosion regulation of the four kinds of tubes, related with the water wall, superheater, reheater and economizer for waste power plant boilers, were analyzed and summarized by taking the classical corrosion rate curves as reference, and the corrosion mechanism varying with the pipe wall temperature in the whole operation temperature range is also summarized. It is concluded that the corrosion rate curve has three remarkable characteristics: bimodal, abrupt change, and virtual-reality. According to the change of wall temperature from low to high, the corrosion rate can be interpreted in terms of electrochemical corrosion and high temperature corrosion respectively. Meanwhile, the corrosion features and the relevant mechanism are discussed by taking the variation of wall temperature range into account. The effect of flue gas temperature on the corrosion rate is discussed, and several key factors affecting the corrosion rate, such as fluid medium temperature, ash accumulation, oxide scale and temperature gradient are analyzed, and the timeliness of corrosion rate curves is discussed in detail.

The cracking phenomenon of a hot-rolled Cu-bearing weathering steel was analyzed by means of micromorphology observation and EPMA surface examination. The distribution characteristics of Mn and S in the hot-rolled Cu-bearing steel and the formed oxide scale are preliminarily assessed, the different enrichment characteristics of Cu-rich phase in copper-bearing steels before and after hot-rolling are comparatively analyzed, and three modes of cracking of hot-rolled Cu bearing weathering steel are put forward. With the synergistic action of hot rolling stress, the grain boundary oxidation, internal oxidation of steel at grain boundary and the enrichment of Cu rich phase in the crack will promote the further serious cracking of the steel.

Marine atmospheric parameters, such as UV light irradiation, temperature, relative humidity, and chloride ions, may affect the corrosion behavior of metallic materials. The effects of the UV lights irradiation and chloride ions on pitting corrosion behaviors of carbon steel were investigated in a simulated marine atmospheres. The 3D images of the pitting were revealed via a combination of dual-beam focused ion beam system with scanning electron microscope (FIB/SEM) system, while the 3D stereoscopic vision was examined by using an X-ray micro-tomography. The results show that UV light irradiation could induce passivation of the carbon steel beneath a thin liquid film, and thus a thin oxide film might form on the carbon steel surface. Pitting corrosion occurred due to the aggressive chloride ions piercing through the oxide film on the surface of carbon steel. Three dimensional (3D) images demonstrated that the flowers-like pitting corrosion products with core-shell structure were formed as the pitting developed. The elemental distributions in the pitting areas exhibited high content of chloride and low content of oxygen in the core, while low content of chloride and high content of oxygen in the shell. The content of chloride ions was the highest in the bottoms of the pits, which then resulted in a pitting mechanism related with autocatalytic reaction.

Aiming at the problem of emerging traces of fluid flow containing rust products on the surface of the bare weathering steel during real service in atmosphere, a stabilizing treatment solution for the weathering steel was designed, and after stabilization treatment, the weathering steel was exposed in a real atmosphere for 0.5 a. The evolution process of the forming rust layer on the weathering steel was monitored and characterized. The corrosion kinetic curve shows that the weight variation of weathering steel gradually reaches a stable state through four stages, and the mass gain (loss) of each stage changes linearly. The enrichment of Cu and Cr in the rust increases the electrochemical protectiveness of the rust layer, reduces the corrosion rate and shortens the stabilization process of the bare weathering steel.

A calculation model of shear capacity for the rust steel-stirrup reinforced concrete beams strengthened with fiber reinforced polymer (FRP) was proposed based on the simplified modified compression field theory (SMCFT), which is considered a few important factors of the existing experiment results, the change of protectiveness of the rust beam, the corrosion rate and yield strength of stirrups etc. Then, 58 groups of test data and three calculation models are collected and analyzed from FRP strengthened rust steel-stirrup reinforced concrete beams are collected and analyzed from of the existing literature. It is proved that the average value and variance of the ratio between the calculated values and the test values of the proposed model in this paper are the smallest, which reflects that the validity of the proposed calculation model for the rust stirrup concrete beam strengthened with FRP.

Based on the previous research work, Sn, Bi, Ti, Sb and other alloying elements were added to the Al-Zn-Ga-Si low-potential sacrificial anode material to improve its overall performance of the anode. By conducting the electrochemical performance test in the conventional seawater environment, a sacrificial anode material with a low driving potential, that meets the requirements, is selected from a variety of prepared anode materials. The selected Al-Zn-Ga-Si-Sb anodes with good comprehensive electrochemical performance were further assessed in a simulated alternating depth and shallowness of seawater environment, especially in terms of its electrochemical performance, while the influence of Sb content on the electrochemical performance of the anode was also investigated through electrochemical performance test and three-dimensional video observation. The results show that the addition of an appropriate amount of Sb can promote the uniform activation and dissolution of the anode materials, therewith improve the activation performance of anodes in complex environments, and reduce the effect of local corrosion. When the Sb content is 0.5% (mass fraction), the comprehensive electrochemical performance of the anode is good and meets the requirements in accord with the general cathodic protection guidelines for high-strength steel. Thus, it may be expected that the Al-Zn-Ga-Si-0.5Sb sacrificial anodes can further be developed to meet the requirement for the high-strength steel cathodic protection in alternating depth and shallowness of seawater environments.

This article summarizes the important preparation methods of high-entropy alloy coating in recent years, focusing on the influence of magnetron sputtering and laser cladding preparation parameters on the structure and performance of coatings. The alloying process and the role of special elements are discussed in detail, especially in terms of the corrosion resistance and oxidation resistance of the acquired high-entropy coatings. The relevant mechanisms of coating failures were interpreted from physical and chemical aspects, and the reasons why high-entropy coating has excellent oxidation resistance were also summarized briefly, furthermore, the key problems that may be faced and still to be solved for the application of this kind of coatings in special working conditions such as marine engineering and aerospace etc. are discussed in detail. On this basis, the future research trend of high entropy alloy coatings is prospected.

The high temperature corrosion of water-cooled wall of the municipal solid waste incineration power plant is an important factor affecting the stable operation of the incinerator. In order to improve the safe operation of the waste incinerator, the existing improvement measures mostly involve the steel pipe selection, surface coating, temperature control and so on. In this paper, aiming at the application of surface coating, the high temperature chlorine corrosion performance of the nickel-based coating on boiler pipe was studied. The surface morphology, microstructure and composition of the alloy coating were characterized by means of optical microscope, vicker's hardness tester, SEM, EDS and XRD. The results show that the nickel-based coating has strong corrosion resistance at high temperature, there are no pores, cracks and other major defects in the coating. The coating can better resist the chloride corrosion and protect the pipeline steels of waste incinerator.