T23,T24合金管材在模拟烟气中的高温腐蚀研究(英文)

Candidate materials for water wall of supercritical and ultra-supercritical utility boilers,T23 and T24,were chosen as the experimental samples and exposed to oxidizing atmosphere,reducing atmosphere and oxidizing/reducing alternating atmosphere separately.The corrosion temperature was 450-550?C.The effects of oxygen con-tent and temperature on the corrosion in reducing atmosphere and alternating atmosphere were investigated.The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) were used to examine the corroded samples.The results show that the corrosion kinetics of T23 and T24 can be described by the double logarithmic equation and parabolic equation respectively.To describe the corrosion of materials accurately it is not sufficient to analyze the macro-mass gain and the macro-thickness of the corroded layer only,but the EDS should be applied to examine the migration depth of corrosive elements O and S.It is revealed that the corrosion becomes more severe when H2S is present in the corrosive gas.S is more active than O,and Cr can reduce the migration of oxygen but not S.The combination corrosion of S and O and pure [S] has a stronger corrodibility than pure H2S.T24 suffers the most severe corrosion at oxygen content of 0.8%.Corrosion is aggravated when the corrosion temperature is above 450 ℃ in the alternating atmosphere.T23 has better corrosion resistance than T24 and W contributes a lot to the corrosion resistance of T23.     

Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of PTB7:PC71BM photovoltaic system

Effects of a benzotriazole(BTA)-based small molecule,BTA2,as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]](PTB7):[6,6]-phenyl-C71-butyric acid methyl ester(PC71BM)organic solar cells(OSCs)were investigated by optical simulation of a transfer matrix model(TMM),photo-induced charge extraction by linearly increasing voltage(photo-CELIV)technique,atomic force microscope(AFM),and the Onsager–Braun model analysis.BTA2 is an A₂-A₁-D-A₁-A₂-type non-fullerene small molecule with thiazolidine-2,4-dione,BTA,and indacenodithiophene as the terminal acceptor(A₂),bridge acceptor(A₁),and central donor(D),respectively.The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum.The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2,resulting in more photogenerated excitons in the ternary OSCs.The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs.AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor,which is disadvantageous to charge carrier transport.The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs,the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.     

镁合金化学镀镍层的生长过程

The initial nickel deposition for the direct electroless nickel plating on non-catalytically active magnesium alloy is critical. The surface morphology and composition of the initial nickel plating coating are obtained by means of the scanning electron microscopy (SEM) and the energy dispersive X-ray (EDS). In addition, the mass gain/loss in the initial nickel deposition process was measured by using the electrobalance. The results showed that the MgO coating was gradually corroded by the plating solution, at the same time, MgF2 produced by F , H and MgO was deposited on the substrate during the initial electroless plating process. The nickel of the initial electroless plating was mostly growing on the boundary between the MgF2 coating and the MgO coating of the activation substrate, and then came to two sides. After that, the Ni-P coating growth rate to cover with the MgF2 coating was prior to the MgO coating. The electroless plating was in company with the substrate corrosion, but the electroless plating rate catalyzed by the exchanged nickel was more than the substrate corrosion rate.     

Modified activated carbons with amino groups and their copper adsorption properties in aqueous solution

Activated carbons were prepared by two chemical methods and the adsorption of Cu (II) on activated carbons from aqueous solution containing amino groups was studied. The first method involved the chlorination of activated carbon following by substitution of chloride groups with amino groups, and the second involved the nitrilation of activated carbon with reduction of nitro groups to amino groups. Resultant activated carbons were characterized in terms of porous structure, elemental analysis, FTIR spectroscopy, XPS, Boehm titration, and pHzpc. Kinetic and equilibrium tests were performed for copper adsorption in the batch mode. Also, adsorption mechanism and effect of pH on the adsorption of Cu (II) ions were discussed. Adsorption study shows enhanced adsorption for copper on the modified activated carbons, mainly by the presence of amino groups, and the Freundlich model is applicable for the activated carbons. It is suggested that binding of nitrogen atoms with Cu (II) ions is stronger than that with H+ions due to relatively higher divalent charge or stronger electrostatic force.     

Electrochemical Corrosion of Carbon—Containing Refractories

The electrochemical examination on the cor-rosion of carbon or carbon containing refractiories at molten slag-liquid interface has been carried out.The electromotive force(E.M.F)of cells with different molten slags:C|molten slag | Fe at elevated temperatures has been measured by means of potentiometer and it is in the range from 250 to 450mV .It is found that the carbon electrode in these cells is anode and whn a counter E.M.F.is applied externally to the cel,the corrosion of carbon electrode will be sup-pressed entirely.Test results show that the local corrosion of carbon containing refractories at slag-metal interface is mainly caused by the mechanism of electrochemical corrosion.     

池式沸腾下PAA与PBTCA对CaCO3结垢的影响

Formation of mineral scales on heat exchangers is a persistent and expensive problem.In the present paper,the calcium carbonate scale inhibition by two inhibitors,polyacrylic acid(PAA) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) has been studied in a pool boiling system.It is found that PBTCA has a better inhibition effect than PAA under the identical conditions.X-ray diffraction (XRD) and Fourier transform-infrared(FTIR) analyses demonstrate that the content of vaterite increases as inhibition effects increase.The metastable crystal froms of vaterite and aragonite are stabilized kinetically in the presence of inhibitors.The relationship between the inhibition effect and the fractal dimension has also been investigated.The result shows that the fractal dimension is higher in the presence of inhibitors.The better the inhibition efect,the higher the fractal dimension.The step morphology was observed by atomic force microscopy(AFM) images.It is shown that the step space on the calcium carbonate surface increases in the presence of inhibitors.Moreover,with the increase of inhibition effect,both the step space and the fractal dimension increase.The step bunching is found on the calcium carbonate by AFM.The better the inhibition effect of the inhibitor,the slower the step velocity in the unbunched location.As a result,the step space becomes wider in the presence of PBCA than that in the presence of PAA.     

Slag Corrosion Resistace of β－Sialon－Al2O3 Composites－Part I. Thermodynamics and Mechanism

Slag corrosion resistance of β－Sialon and β－Sialon-Al2O3 composites has been studied .The effects of FeO content and temperature on corrosion rate have been investi-gated by mens of dip method(static and self-rotating).The corrosion process and microstructural analysis.It is shown that FeO preferentially attacks β-Sialon in the composite and the protruded corundum grains would gradualy fall off into the slag.     

Study on Mechanism of Reaction Between AOD Slag and Rebonded Magnesite—Chrome Brick

The influence of the composition of AOD slag on the corrosion of rebonded magnesite-chrome brick has been studied by analyzing the residual bricks at the tuyere zone of AOD .It indicates that the corrosion degree increased with the increase of the basicity of slag and decreased with the increase of the content of MgO ,Cr2O3 and Al2O3 in slag.And the addition of refractories to slag up to satura-tion could decrease the corrosion abiliy of sag.It is important to make a resonable slagmaking rule and ensure the percentage of MgO in slag more than 11wt% for pro-longing the service life of lining.     

A novel green inhibitor for C-steel corrosion in 2.0 mol·L~(-1) hydrochloric acid solution

The corrosion inhibition characteristics of aqueous extract of seeds of Melia azedarach L.(MA) have been studied as eco-friendly green inhibitor for corrosion control of C-steel in 2 mol·L~(-1) HCl solution by gravimetric and electrochemical methods. The results depict that, the extract inhibits efficiently the corrosion of carbon steel in hydrochloric acid. The efficiency of extract is increased with increasing the extract concentration but independent on the studied temperature. The adsorption of the extract components onto the steel surface was found to be spontaneous, and follows Langmuir adsorption isotherm. The surface morphology of C-steel, in the absence and presence of MA extract in 2.0 mol·L~(-1) hydrochloric acid solution, was studied using scanning electron microscopy(SEM).     

Catalytic mechanism of manganese ions and visible light on chalcopyrite bioleaching in the presence of Acidithiobacillus ferrooxidans

The bioleaching of chalcopyrite is low cost and environmentally friendly,but the leaching rate is low.To explore the mechanism of chalcopyrite bioleaching and improve its leaching rate,the effect and mechanism of manganese ions(Mn²⁺) and visible light on chalcopyrite mediated by Acidithiobacillus ferrooxidans(A.ferrooxidans) were discussed.Bioleaching experiments showed that when both Mn²⁺ and visible light were present,the copper extraction was 14.38% higher than that of t...     

高浓度氯离子环境中铜合金缓蚀的电化学研究

应用线性电位扫描(LSV)和Tafel实验等电化学测试技术,研究了苯并三氮唑(BTA)浓度、缓蚀剂的复配、温度对铜合金在高浓度氯离子(25%氯化钙溶液)环境中腐蚀行为的影响。结果表明:缓蚀剂浓度改变将引起缓蚀效果的变化,BTA浓度较低时,铜合金腐蚀电位随缓蚀剂浓度增大而升高,腐蚀速率降低;BTA浓度超过0.2%后,铜合金腐蚀电位和腐蚀速率趋于稳定;NaNO2、Na2MoO4、(NH4)2MoO4等缓蚀剂与BTA复配,对改善缓蚀效果有一定作用;温度对缓蚀效果有重要影响,铜合金在高浓度氯离子溶液中的腐蚀速率随温度的升高而加快,缓蚀剂的缓蚀效果随温度的升高而降低。     

苯并三氮唑及其衍生物对铜的协同缓蚀效应

以苯并三氮唑(BTA)和溴代正丁烷为原料,采用一步法合成了N-丁基苯并三氮唑(N-BBTA),研究了BTA、N-BBTA以及N-BBTA与BTA的复配体系对铜在3％(质量分数)NaC1溶液中的缓蚀行为.结果表明,单一N-BBTA和BTA对铜均具有一定的缓蚀能力.当N-BBTA、BTA浓度为10 mmol/L时,缓蚀率分...     

Effect of benzotriazole (BTA) addition on Polypyrrole film formation on copper and its corrosion protection

Benzotriazole (BTA) was added in a conducting Polypyrrole (PPy) film prepared on copper in oxalic acid aqueous solution containing pyrrole monomer to improve corrosion protection by the PPy film and reduce copper corrosion. When BTA was added in the preparation solution, the copper surface was covered by a BTA–Cu complex layer before the anodic polymerization of PPy was started. On the copper surface with the BTA layer, the initial dissolution of copper was inhibited and the PPy polymerization-deposition was started immediately after the anodic current was imposed. The PPy film thus formed was doped with oxalic ions and ionized BTA and was homogeneous in thickness and strongly adhesive. The PPy film containing BTA protected the copper from corrosion in 3.5 wt.% NaCl solution. In 400 h of immersion, copper dissolution was inhibited with 80% protection efficiency relative to that of bare copper.     

原子力显微镜研究苯并三氮唑对铜的缓蚀作用

铜以及铜合金由于其优良的抗腐蚀性能,广泛用在冷却水系统中,苯并三氮唑(BTA)常常作为铜的缓蚀剂。将传统电化学方法和原子力显微镜(AFM)测试技术相结合,对人造海水中BTA作用于铜电极的缓蚀行为进行了研究。结果表明,BTA能够有效减缓铜在海水中的腐蚀,且随着缓蚀剂浓度的增加,缓蚀效果越明显,100 mg/L的BTA就能够高效的保护铜。电化学结果表明,BTA能够在铜的表面形成致密的保护膜[CuBTA]n;AFM测试表明,随着时间的进行,保护膜越来越致密,保护性能也越好。     

Inhibiting effects of benzotriazole on the corrosion of α-Al-bronze in saline water

The inhibiting effect of benzotriazole (BTA) on the corrosion of -Al-bronze (Cu-7% Al) in 3.4% NaCl was studied. BTA showed good inhibition effects from short up to extended periods of time (about six weeks). The morphologies of the alloy surface were monitored after various periods of corrosion in the absence and presence of BTA, using SEM. The corrosion products were identified by X-ray diffraction. Corrosive attack occurs very early in the absence of BTA, leading to general and pitting corrosion. BTA was found to have a stronger inhibiting effect on the anodic dissolution of copper than on the cathodic reduction of oxygen. The current-potential relation is divided into two regions: region I within which BTA has a strong effect on the charge transfer kinetics, and a limiting current region where BTA has no significant inhibiting effect. It is also shown that the interaction of BTA with a Cu₂0-covered alloy surface is faster than on reduced alloy surfaces, although the protection efficiency on the latter is slightly better than on the former.     

The synergetic effect of benzylamine on the corrosion inhibition of copper by benzotriazole

Passivating films, formed by the anodization of copper in alkaline benzotriazole (BTA) solutions, have been investigated. Addition of benzylamine to the anodizing solutions was found to lead to much faster passivation and greater corrosion resistance in aqueous chloride. These passivating films appear to consist mainly of a [Cu(II)BTA₂]_n polymeric network.     

Benzotriazole as inhibitor for copper with and without corrosion products in aqueous polyethylene glycol

Electrochemical methods, including polarization experiments and impedance spectroscopy, were used to evaluate the effectiveness of benzotriazole (BTA) in an aqueous solution of polyethylene glycol (PEG) in protecting polished archaeological copper or archaeological copper covered with corrosion products. The adsorption of PEG on the polished copper significantly limited the corrosion current. The presence of benzotriazole enhanced the protection of the polished copper, giving maximum protection at a concentration of 10^–2moll^–1 of BTA in 20 vol% PEG 400 solution. On the other hand, PEG solutions caused degradation of the corrosion products of the copper. This degradation increased with time. When BTA was added, the corrosion products were preserved and, the higher the BTA concentration, the more the corrosion current decreased. In PEG 400 solution protection of the corrosion products of the copper by BTA improved over time.     

Experimental and atomistic simulation studies of corrosion inhibition of copper by a new benzotriazole derivative in acid medium

The efficiency of N-(2-thiazolyl)-1H-benzotriazole-1-carbothioamide (TBC) as a non-toxic corrosion inhibitor for copper in 0.5 M HCl has been tested by weight loss and electrochemical techniques. Electrochemical techniques show that TBC is a mixed-type inhibitor and its inhibition mechanism on copper surface is adsorption assisted by H-bond formation. Impedance measurements show a wide peak presumably given by more than one time constant in the presence of TBC. Also, impedance results show that the values of CPEs (constant phase elements) tend to decrease and both polarization resistance and inhibition efficiency tend to increase with increasing of TBC concentration due to an increase in the electric double layer. Monte Carlo simulations incorporating molecular mechanics and molecular dynamics show that the TBC adsorb on the copper surface firmly through the thiazolyl and carbothioamide groups, the adsorption energy as well as hydrogen bond length have been calculated for both TBC and benzotriazole (BTA) for comparison. Quantum chemical calculations reveal that TBC has higher HOMO, lower LUMO, lower energy gap and lower dipole moment (μ) than BTA, which proves that TBC is better copper corrosion inhibitor compared with BTA in 0.5 M HCl.     

An electrochemical and Raman spectroscopic investigation of synergetic effects in the corrosion inhibition of copper

The synergetic inhibition of copper corrosion by benzotriazole (BTA) and benzylamine (BZA) in chloride and cyanide media is assessed by voltammetric and ac impedance measurements. BZA enhances the performance of the strong inhibitor BTA by accelerating the growth of a protective surface layer; used alone, BZA is ineffective as an inhibitor. The competitive adsorption of aggressive anions and inhibitors is studied by surface enhanced Raman scattering (SERS). The dramatic increase in corrosion caused by low concentrations of cyanide ions is shown to be due to the displacement of BTA from the copper electrode surface; comparisons are made with the behaviour of mercaptobenzoxazole (MBO).     

钝化工艺对HEDP镀铜层耐蚀性的影响

采用盐水浸泡试验、硝酸点滴试验以及电化学测试方法,研究了苯并三氮唑、苯并三氮唑与Cr(Ⅲ)复配、苯并三氮唑与铈盐复配、Cr(Ⅵ)以及HAD无铬钝化工艺对HEDP镀铜层耐蚀性的影响。结果表明,经苯并三氮唑复配钝化液钝化处理后,钝化膜耐蚀性较单一的苯并三氮唑钝化稍有提高,但均不及Cr(Ⅵ)钝化处理,而经HAD无铬钝化处理后,钝化膜耐硝酸点滴时间最长,在3.5%Na Cl溶液中的Rct最大,icorr最小,耐蚀性明显优于Cr(Ⅵ)钝化处理。