Chemistry Commons^™

Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

There is an active international interest in lead-bismuth eutectic and similar liquid lead systems because of the relevance to the transmutation of nuclear waste, fast reactors, and spallation neutron sources. A successful program in nuclear waste processing that includes transmutation in accelerator-driven systems and fast reactors, would significantly decrease the space requirements for geological repositories.

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For lead bismuth eutectic (LBE) systems, there is an additional challenge because the corrosive behaviors of materials in LBE are not well understood. Most of the available information …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of environmental and mechanical parameters on environment induced degradations of candidate target structural materials for applications in spallation-neutron-target systems, such as accelerator-driven systems for the transmutation of waste. The materials selected for evaluation and characterization are martensitic stainless steels including Alloys HT-9, EP-823 and Type 422 stainless steel (SS).

More recently, this experimental program has been expanded to evaluate the effect of molten lead-bismuth eutectic (LBE) on the corrosion behavior of target structural materials in the presence of oxygen. Since the Materials Performance Laboratory (MPL) at UNLV currently cannot …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The corrosion of structural materials is a major concern for the use of lead-bismuth eutectic (LBE) systems for nuclear applications such as in transmuter targets or fast reactors. Corrosion in liquid metal systems can occur through various processes, including, for example, dissolution, formation of inter-metallic compounds at the interface, and penetration of liquid metal along grain boundaries. Predicting the rate of these processes depends on numerous system operational factors: temperature, system geometry, thermal gradients, solid and liquid compositions, and velocity of the liquid metal, to name a few. Corrosion, along with mechanical and/or hydraulic factors, often contributes to component failure. …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 09/01/2003-11/30/2003, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang

Journal of Electrochemistry

In this work, potential-modulation method was used in two-step anodization process to make an AAO template with Y-type nanochannels. Then Y-type carbon nanotubes with controlled length and branch angle were prepared in the template based on chemical vapor decomposion (CVD) method with Co particles as catalyst and C₂H₂ as carbon source. The Y-type nanotube branches exhibit the angle distribution ranging from 20° to 120°. The results demonstrated that the oxidation potential should be responsible for the angles and length of the branches. Short pulse and high oxidation potential will result in the short and dense nanotube branches.

Study On The Gas Generation In Different Charging Voltage During Formation Process In Polymer Lithium-Ion Battery, Li Huang, Ming-Gang Jin, Hui-Qun Cai, Ming-Sen Zheng, Quan-Feng Dong, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

The gases of polymer lithium-ion battery (PLI) generated under different voltages during the first charging process were examined by means of gas chromatography (GC), and the mechanism of the gas generation was discussed. The electrolyte used in batteries was 1 mol/L LiPF₆-EC～DMC～EMC=1∶1∶1(in volume). The results showed that when the charging voltage is less than 2.5 V,  the main component of generated gases are H₂ and CO₂, and when the charging voltage is 2.5 V, EC begins to decompose. Due to the decomposition of EC, the main generated gas is C₂H₄ when the …

Electrochemical And In-Situ Scanning Tunneling Microscopy Studies On The Sb Underpotential Deposition On Cu Single Crystal Electrodes, Ji-Hong Wu, Jia-Wei Yan, Jing Tang, Wen-Yun Hu, Bing-Wei Mao

Journal of Electrochemistry

We report electrochemical and in-situ STM studies on Sb UPD onto Cu(111) and Cu(100) electrode surfaces in HClO₄ and H₂SO₄ solutions. The results indicate that the electrode surface structure as well as anion can considerably influence Sb UPD. Sb UPD on Cu(100) forms open adlayer structures, which is accompanied by surface alloying due to the more open structure of the (100) surface, On Cu(111), a more compact Sb adlayer is formed instead. Anion adsorption influences the dynamics as well as the adlayer structure of Sb UPD. Owing to the strong adsorption of SO₄^2-, …

Application Of Hydrogen-Storage Alloy Electrode In Electrochemical Reduction Of Glucose, Hui Chen, You-Gen Tang, Zheng Tang

Journal of Electrochemistry

Electrolysis of glucose was performed at constant potential using hydrogen-storage alloy as catalytic reduction electrode. It was found that the superficial treatment and activation of hydrogen-storage alloy powder had obvious effects on improving the current efficiency of sorbitol. Under the optimums, current efficiency of sorbitol by electrolyzing glucose was over 94%. The yield of sorbitol was over 80%, the lifespan of electrode was tested and analyzed, the ways of regeneration were discussed.

Study On Electrochemical Behavior Of Sus316l Stainless Steel After Surface Modification, Cheng-Hao Liang, Liang Guo, Wan Chen, Jing-Xiao Liu

Journal of Electrochemistry

The surface modification for SUS316L stainless steel was carried out by electroplating Rh, ion beam assisted deposition Ta₂O₅ and sol-gel-derived TiO₂. In Tyrode's stimulated body fluid, the surface modified samples had been investigated with electrochemical techniques. The results indicated that the electrochemical stability and dissolution were improved significantly after surface modification. Moreover, as to ion beam assisted deposition Ta₂O₅ and Sol-gel-derived TiO₂ film, the metal's d orbit electron holes filled up by the oxygen electrons made against the adsorption of hydrogen. Thus the cathode process, which is controlled by the hydrogen …

Pitting Characteristics Of Cu-50/60ni Alloys In Nacl Solution, Jie Li, Yan Niu, Shi-Zhe Song

Journal of Electrochemistry

The pitting behavior of nanocrystalline Cu-50/60Ni and cast Cu-50/60Ni alloys in different concentration of NaCl solutions has been investigated using various electrochemical methods. A logarithmic dependence of the passive breakdown potential (E_b), which is established using dynamic potential scan technic, on the chloride concentration was obtained for both alloys. The study on pitting propagation of both alloys was carried out using potential step chronocurrent method. As long as pits initiate on both alloys, the pits on nanocrystalline Cu-Ni alloys develop faster than those on cast alloys.

Preparation And Properties Of The Composite Microporous Pvdf-Hfp/Sio2 Based Polymer Electrolytes, Bao-Wen Zhang, Lu Qi, Hui Hen, Xiao-Hui Zhu, Li-Yan Liu, Yun-Xiang Ci

Journal of Electrochemistry

Microporous PVDF-HFP/SiO₂ film were prepared using a solvent/nonsolvent method-phase inversion method and the volatile plasticizers DMC, DEC or PC. The conductivity of the films increased pore volume measured by a nonsolvent uptake method. The conductivity of 1.86×10^-3 S⋅m^-1 were obtained using the liquid electrolyte LiPF₆(1 M) in EC/DMC (1:1).

Optimizing Catalyst Layer Composition Of Pemfc By Orthogonal Method, Ming-Hua Wang, Xin-Jian Zhu, Guang-Yi Cao, Sheng Sui, Qing-Chun Yu, Ming-Ruo Hu, Zheng-Yu Fan

Journal of Electrochemistry

The optimal composition of catalyst layer in a PEMFC electrode was studied through orthogonal method. It was showed that the performance of hydrophilic electrodes, in which there is no PTFE in the catalyst layer, were more favorable than that of hydrophobic electrodes. According to this condition, the power density of PEMFC attained 0.37 w·cm^-2 when the Nafion loading was 1.4 mg·cm^-2, and the Pt loading was 0.4 mg·cm^-2 in the catalyst layer, using H₂ as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst …

Study On Degradation Of Phenol By Electrochemical Oxidation, Yue-Li Liu, Hong-Hua Ge

Journal of Electrochemistry

Electrochemical oxidation of phenol was carried out by the Dimensionally Stable Anodes (DSA) electrode, which has been discarded as waste by alkali chloride factory. The result indicates that a good phenol removal can be obtained under certain phenol concentration by the DSA electrode. The key factor in effecting phenol removal of electrochemical oxidation is applied current density, the following factors are pH, electrolyte concentration and phenol concentration. After experiments, the optimal test conditions are 30 mA/cm², pH 10, electrolyte concentration 10 mg/L, phenol concentration 10 mg/L.67% CODcr removal and 90% absorbance removal are gained by electrochemical oxidation for …

Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu

Journal of Electrochemistry

The electrochemical behaviors of platinum electrode were studied by cyclic voltammetry in 1mol/L sulfuric acid solution and 1mol/L sulfuric acid solution contained phenol. The adsorption characteristics of phenol and the intermediat on electrode surface have been discussed. The reactive reversibility and oxidation mechanism of phenol on electrode process have been investigated.The potential of characteristic adsorption was suggested. The various products woud be formed when the electrode potential was greater than the one of characteristic adsorption.

The Study Of Green Corrosion Inhibitors For Mild Steel 907 In Natural Seawater Environment, Ping Gong, Min Du, Qing-Zhang Wang, Zhen-Jun Mu

Journal of Electrochemistry

Nine green compounds, including calcium gluconate, zinc gluconate, zinc sulfate, garlic, ACUSOL 445N, OS-15, APG, OCTA and STPP were selected according to the methods of molecule design and function groups prune. The functions of combined corrosion inhibitors mixed by the compounds mentioned above for mild steel in seawater were studied in this work using the methods of polarization curve and weight-loss.The best weight ratio and distinct synergistic effect of calcium gluconate, zinc sulfate and OCTA were studied by Latin experiment. The afgereffects of the best weight ratio corrosoin inhibitor were studied by subsection experiment. In this way, a kind of …

The Study On Carbon Nanotube-Loaded Pt Catalysts For Proton Exchange Membrane Fuel Cells, Hong Zhu, Feng-Juan Ge, Xiao-Hong Kang, Yu-Guo Yang, Yun-Hua Xu

Journal of Electrochemistry

Carbon nanotube-supported-platinum (Pt/CNTs) and carbon-supported-platinum (Pt/C) catalysts were synthesized by in-situ chemical reduction. They were analyzed using TEM and XRD, then made into electrodes to be part of assemable PEMFC for the performence tests. The resulted show that Pt clusters in both catalysts are of small particle size (about 4nm), and Pt/CNTs exhibits a higher catalytic activity than Pt/C.

Effect Of Dspp Al2O3 On Electrical Properties Of Polymer Electrolyte, Hai-Fen Xie, Xiao-Xiang Sun, Yi-Pin Wang, Guang-Yuan Li

Journal of Electrochemistry

The PEO-NaSCN polymer solid electrolytes by adding dispersed second phase particles (DSPP) of Al₂O₃ were studied. The characteristics of solid electrolytes and conductivity values are dependent on DSPP Al₂O₃ sizes and its contents. It was found that when the Al₂O₃ sizes are less than 1 μm, which is a criticle size, the sample conductivities were larger than those of the pure PEO-NaSCN samples and when the Al₂O₃ sizes are larger than 1 μm then the sample conductivities are less then those of the pure samples. The maximum conductivity …

The Current Fluctuations Of Carbon Steel In Nano2-Nacl Solutions, Yu-Ming Tang, Yu Zuo

Journal of Electrochemistry

The characteristics of current fluctuations of A3 carbon steel in NaNO₂-NaCl solutions were studied with potentiostatic and potentiodynamic polarization methods. The steel remained stable passivation in 0.1 mol/L NaNO₂ solution without Cl^-. After NaCl was added in to the solution, current fluctuations with a characteristic of quick increase and slow decrease occurred, indicating quick dissolution and slow re-passivation of the metastable pits. The metastable pitting may cause accumulated corrosion damage around certain area and result in observable pits. With the increase of chloride concentration, the occurring potential for metastable pits Em rised, and peak values …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Quarterly Progress Report (June 1 – August 31, 2003), Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

As indicated in the original proposal, the primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate target materials for applications in spallationneutron- target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including Alloy HT-9, Alloy EP 823 and Type 422 stainless steel. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these materials are being evaluated in aqueous environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. …

Growth Of Well-Defined Zno Microparticles By Hydroxide Ion, Ruth Mcbride, Declan Mccormack, John Kelly

Articles

The morphology of the microcrystalline zinc oxide formed by reaction of zinc salts with sodium hydroxide depends critically on the reaction conditions. To understand this, the nature of the solid product has been probed by scanning electron microcopy (SEM) and X-ray diffraction (XRD) and the concentration of zinc remaining in the solution has been determined at regular intervals throughout the reaction. Two general preparative procedures have been followed. The first, which involves simply heating an aqueous solution containing Zn(NO3)2 (0.025 M) and sodium hydroxide (0.375 M) to 101 uC and maintaining it at that temperature for periods of up to …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 06/01/2003-08/30/2003, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Annual Report -Phase Ii 09/01/2002-08/30/2003, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Synthesis And Electrochemical Properties Of K2Feo4, Ning Zhou, Shi-Hai Ye, Yong-Long Wang, Xue-Ping Gao, Dong-Feng Lin, Zuo-Xiang Zhou, De-Ying Song

Journal of Electrochemistry

The K₂FeO₄ used for new positive electrode materials was prepared. The primary batteries were used in different concentration of electrolyte and different currents. In 9 mol/L KOH , the capacity was the best. The higher the concentration of electrolyte, the lower the electric potential was. When the batteries discharged in 0.4 C , the capacity reached 521.3 mAh/g. By XRD, we gave the reasonable explanations for the discharge products of K₂FeO₄. Possible mechanism of discharge is discussed.

Corrosion Fatigue And Dynamic Strain Aging Of Duplex Stainless Steel In Aqueous Solution, Chuan-Ming Tseng, I-Hsuang Lo, Wen-Ta Tsai

Journal of Electrochemistry

The corrosion fatigue and dynamic strain aging behaviors of 22%Cr duplex stainless steel (DSS) in sodium chloride solutions were investigated. Austenitic 316L SS and ferrtic 430 SS were also used in this study for a comparison. The experimental results showed that no stress corrosion cracking (SCC) occurred in all these SSs tested in 3.5wt% NaCl solution at 80 ℃. However, dynamic strain aging (DSA) occurred in 316L austenitic SS and 22%Cr DSS during slow strain rate testing (SSRT) in this solution.The occurrence of DSA was dependent on solution temperature,strain rate and the presence of austenitic phase. The corrosion rate of …

Synthesis Of Polyunit Vapor Phase Inhibitor And Its Volatile Corrosion Inhibition Performance, Da-Quan Zhang, Li-Xin Gao, Guo-Ding Zhou

Journal of Electrochemistry

A Mannich Base derivative (BMMCH), containing two morpholinum moieties and one cyclohexylamnonium moiety, was synthesized through aminomethy1 reaction. Its configuration was verified by IR and ¹H-NMR. Its volatile rustproofing effect was appraised by volatile rustproofing sieve test and vapor inhabitability test. The result shows that BMMCH has good protection effect for carbon steel. BMMCH has lower volatility compared with dicyclohexylamnonium nitrite (DICHAN) via closed space volatile weight-loss test. The inhibition mechanism was studied by potentiodynamic polarization electrochemistry technique in ASTM simulated atmospheric water. The corrosion potential of carbon steel electrode shifted to a negative direction when BMMCH was joined …

Effect Of Heat Laminating Aggregation Status Of Polymer Lithium-Ion Battery Cathode On Battery Performance, Ming-Gang Jin, Quan-Feng Dong, Ming-Sen Zheng, Li Huang, Hui-Qun Cai, Jin-Qua You, Zu-Geng Lin

Journal of Electrochemistry

Multi-layer heat laminated polymer lithium ion battery was made, the effect of temperature of cathode laminating on battry performance was also investigated. It was discovered that suitable temperature of cathode laminating is critical to battery performance and is a key parameter to manufacture process control of polymer lithium ion battery.

Influence Of Marine Organisms Upon Corrosion Of Steel Piling Systems, Jiunn-Shyong Luo, Cliff Rau, Kuei-Ching Chen

Journal of Electrochemistry

To study the influence of marine organisms upon corrosion of ASTM A36 steel piling sysems, specimens were immersed in both natural and synthetic seawater. Electrochemical techniques such as linear polarization resistance and electrochemical impedance scan(EIS) were applied to evaluate corrosion of the steel. The results indicated that attachment of marine organisms to form fouling layers on the steel surface reduced general corrosion, but localized corrosion occurred underneath marine organisms. An equivalent circuit model was established to simulate attachment of marine organisms upon carbon carbon steel surfaces.

Severe Corrosivity And Its Eletrochemical Mechanism Of Seawater In Xiamen Sea Area To Al-Mg Alloys, Le-Yun Lin, Yue-Hong Zhao

Journal of Electrochemistry

The surface layer seawater of different sea areas in China exhibit different corrosivity to Al-Mg alloys according to the experiment results of 16 years exposure in seawater. The seawater in Xiamen sea area possesses severe corrosivity while seawater in Qingdao possesses the mildest corrosivity to Al-Mg alloys with better regularity of corrosion behavior. The present paper illustrates by experiment data that the strongest corrosivity of Xiamen seawater to Al-Mg alloys is owing to the low salinity of the seawater and the “electrolyte effect” come from it. The 16 year corrosion data and corrosion morphology of the typical Al-Mg alloys from …

Discussion On Factors Of Unstable 304 Stainless Steel Stress Corrosion Cracking, Xin-Sheng Zhang, Chun-Chun Xu, Gang Hu

Journal of Electrochemistry

The 304 stainless steels were stretched at low temperatures to get different martensite phase transformation. Ferrmagnetometer was used to measure the martensite phase content. It was found that the dislocation density of 304 stainless sted was increased unavoidably with increase of deformation. Transmission electron microscope (TEM) was used to study the distribution of the dislocation. The influence of microstructure change on SCC of 304 stainless steel was discussed by slow strain rate testing (SSRT) in 42% MgCl₂ boiling solution,metallurgical microscope and scanning electron microscope (SEM).The results showed that martensite phase and dislocation flaw act together on the SCC susceptibility …

The Electroless Plating Ni-Fe-P Alloy And Its Voltammetric Behavior, Sen-Lin Wang, Hui-Huang Wu

Journal of Electrochemistry

Electroless Ni-Fe-P alloy deposition from an alkaline bath, containing sodium hypophosphite as reducer, boric acid as buffer agent and sodium citrate as complexing agent, was investigated. To increase the plating rate and to inprove the bath stability, the deposition parameters were optimized. The effects of process parameters (pH, temperature and mole ratio of [Fe²⁺]/([Ni²⁺]+[Fe²⁺]) on the plating rate and deposit composition were examined and it was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the percentage of iron in the electroless …