炔氧甲基季胺盐和咪唑啉对N80在饱和CO2的3%NaCl溶液中的缓蚀性能研究

利用交流阻抗(EIS)、线性极化、动电位极化和拉曼光谱等方法对炔氧甲基季胺盐和咪唑啉在常温常压CO2饱和的模拟油田产出水中的电化学行为和缓蚀性能进行了研究．结果表明：随两种缓蚀剂的加入，体系的阳极电流都明显减小，自腐蚀电位都明显正移，都存在阳极脱附现象和浓度极值现象；炔氧甲基季胺盐的极值浓度为150mg／L，而咪唑啉的极值浓度为100mg／L咪唑啉缓蚀剂的缓蚀效果更佳，但在7m／s时直至缓蚀剂浓度为300mg／L时也没有发现静态下的浓度极值现象。     

几种因素对油套管钢CO2腐蚀行为影响

研究了流动条件下CO2分压、流速、原油含水率、溶液Cl^-浓度及pH值对3种油套管常用材料N80、P105和SM110腐蚀行为的影响．90℃、1．5m／s时，随CO2分压升高，材料的腐蚀速率先升后降，在CO2分压为2．5MPa时，除N80钢外，其它材料的腐蚀速率达到最大值；90℃、CO2分压为2．5MPa时，随着流速的增加，腐蚀速率先升后降，在流速为1．5m／s时，材料的腐蚀速率达到最大值；原油含水率对材料的腐蚀速率影响较大；溶液的pH值及Cl^-浓度对材料的腐蚀速率影响不明显．     

HAl77-2黄铜在流动海水中的电化学行为

利用旋转圆环电极、电化学阻抗谱（EIS）和线性极化方法研究了HAl77—2黄铜在流动海水中的电化学行为。结果表明,HAl77-2黄铜在不同流速海水中呈现不同的EIS特征,静止海水中EIS呈现扩散影响的特征;流速〈4m／s的海水中,EIS大体表现为电荷传递控制的特征;流速≥4．5m／s时,EIS谱线低频部分呈现感抗弧。HAl77—2黄铜的腐蚀速率受海水流速的影响,流速≤2m／s时,腐蚀速率随着流速的增大基本上呈线性递增;流速在2m／s～4m／s范围内,腐蚀速率的变化较小;流速≥4．5m／s时,试样出现点蚀,且随着流速的增加腐蚀速率又迅速增大。     

X70和16Mn钢腐蚀行为比较：Ⅲ.腐蚀磨损

用旋转试片装置和失重法比较X70钢和16Mn钢在含沙溶液中腐蚀磨损行为，研究流速、介质pH值、温度等因素影响.结果表明，2种管道钢存在相同临界流速，045 m/s，高于临界流速时，腐蚀磨损失重明显增加.同时温度升高也使钢的失重增加.此外腐蚀和磨损的交互作用十分明显，尤其在酸性介质中，交互作用影响可占总失重量的80%以上.X70钢抗腐蚀磨损性能较好.原因是X70钢易形成致密保护膜和有较高表面硬度.前者导致在酸性和弱碱性介质中，X70钢的失重较小，只有在强碱性下，二者腐蚀磨损失重几乎相同；后一因素使得X70钢在高流速下有较好抗磨损性.      

双氧水改性二氧化钛的光催化性能研究

研究了用微乳法制备纳米二氧化钛粉末的工艺，以及在紫外光照射下，TiO2和H2O2分别以及两者结合对于甲基橙溶液的降解作用。结果表明用微乳法可以制备粒度为23．2nm的纳米TiO2粉末；在紫外光照射下，H2O2可以有效地降解甲基橙溶液；当H2O2浓度从1mmol／L增加到10mmol／L，甲基橙的吸光度直线下降；当H2O2浓度达到10mmol／L时，降解率可以达到99％；TiO2也可以有效地降解甲崔橙溶液，当TiO2的浓度为0．50～0．75g／L时，降解率最大；用H2O2对TiO2进行改性后，可以有效地降解甲基橙溶液，固定TiO2的量为0．5g／L时，当H202浓度为4mmol／L时，甲基橙溶液的吸光度达到最低；当H2O2浓度处于10mmol／L以上时，甲基橙溶液的吸光度却出现无规则的变化。     

咪唑啉型缓蚀剂中疏水基团对N80钢在CO2饱和的3%NaCl溶液中的缓蚀性能影响

合成了四种含有不同疏水基团的咪唑啉型缓蚀剂,即正丁基咪唑啉(IM-4)、壬基咪唑啉(IM-9)、十一烷基咪唑啉(IM-11)和十七烷基咪唑啉(IM-17),产物经红外,紫外光谱等进行表征.在静态及动态条件下,用失重法、电化学等方法研究各缓蚀剂对N80钢在CO2饱和的3%NaCl溶液中的缓蚀性能.结果表明,静态条件下,缓蚀剂的缓蚀性能与疏水基团的碳链长度、空间位阻及其水溶性有关;在介质流速为5 m/s的动态条件下,缓蚀剂的缓蚀效率显著降低,对缓蚀剂的疏水和屏障作用要求更高.     

新型缓蚀剂TG500在高CO2和Cl-环境中的缓蚀行为

在高温高压高CO2和Cl^-环境中，用静态高温高压模拟试验方法对不同浓度的TGS00新型咪唑啉季铵盐缓蚀剂进行了缓蚀效率测试．结果表明，TGS00缓蚀效率随加入量增加而增加，浓度增加到0．3g／L后，缓蚀速率提高不明显．同时研究N80套管钢表面的腐蚀产物，缓蚀剂浓度较低时，以均匀腐蚀为主，加入量提高到0．3g／L时，除局部少量点蚀外，无其它明显腐蚀特征．     

动态环道腐蚀评价系统在某油田海底管道流速研究中的应用

采用动态环道腐蚀评价装置FlowLoop对某油田某海底管道不同流量及油水分离前后的腐蚀状况进行了模拟研究,研究表明：空白体系中,随着流速增大,挂片腐蚀速率整体趋于增大,在1．5m／s时腐蚀速率最低;在各流速条件下,垂直管道挂片腐蚀速率均大于水平管道;添加缓蚀剂后,腐蚀得到不同程度的抑制,1．5m/s流速下缓蚀剂缓蚀率为88％左右,2．5m／s流速下缓蚀率为60％左右。     

一种苯胺类席夫碱对N80钢在盐酸介质中的缓蚀性能

合成了一种席夫碱:4-氯-N-[(吡啶-4基)-亚甲基]苯胺(CNP),并采用失重法、电化学阻抗谱和动电位极化曲线等,研究了CNP对N80钢在1mol/L HCl溶液中的缓蚀性能。结果表明,在1mol/L HCl溶液中,当缓蚀剂摩尔浓度为1.0mmol/L时,缓蚀率达到86.17%。其在N80钢表面吸附满足Langmuir吸附等温式,是一种混合型缓蚀剂。     

CO_2对X80钢在库尔勒土壤模拟溶液中腐蚀行为的影响

通过动电位极化、电化学阻抗和浸泡失重等方法,考察了X80钢在含有不同浓度CO2的库尔勒土壤模拟溶液中的腐蚀行为,采用扫描电镜对腐蚀形貌进行了观察。结果表明:当土壤模拟溶液中通入的CO2和N2的体积比分别为CO2∶N2=10∶90,20∶80和30∶70时,不同浓度的CO2都促进了X80钢在库尔勒土壤介质中的腐蚀速率。这主要是因为通入的CO2使模拟溶液的p H值显著下降,导致溶液变为酸性,腐蚀过程由原来的氧控制变为了析氢反应为主,阴极反应过程进一步加快。另一方面,溶液中存在的CO2增加了X80钢表面腐蚀产物膜的缺陷,对基体的保护作用下降。这些因素导致X80钢的腐蚀速率增大。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。