交流电磁场对几种金属腐蚀行为的影响

采用交流电磁场对碳钢电极进行静态试验腐蚀,并利用循环冷却水系统动态模拟装置,在恒定工况条件(水浴55℃,流速1.2m/s,入口温度30±1℃)下,对碳钢、不锈钢和黄铜等进行了交流电磁场影响腐蚀的动态腐蚀试验。静态腐蚀试验结果表明:交流电磁场可减小碳钢试样的腐蚀速率,证明了电磁场对碳钢腐蚀防护的有效性。动态腐蚀试验结果表明:交流电磁场对金属腐蚀速率及点蚀倾向有一定影响,对不同金属影响不同;交流电磁场作用下碳钢受磁矩影响呈现缓蚀,腐蚀速率呈下降趋势;而对不锈钢和黄铜腐蚀则表现出强化传质作用,致使金属的耐蚀性下降,腐蚀速率加快。     

污水深度处理后回用于循环冷却水的试验研究

本文介绍了将污水经深度处理后回用于循环冷却水的中试试验过程，确定了该试验工艺路线的技术可行性，它的实施将产生良好的社会效益。     

中水回用电厂循环冷却水系统相关材料的腐蚀数据

采用静态浸泡和动态腐蚀试验,测试了某电厂采用中水作为电厂循环冷却水对相关设备所用材料(TP317L、TP316L、TP304L、TP321、1Cr18Ni9Ti、A3碳钢、Q235碳钢、普通铸铁、HSn70-1A、HA177-2、B30等)的腐蚀速率,为回用中水的电厂提供了相关设备材质的腐蚀数据,有利电厂在选择循环冷却水相关设备时从腐蚀的角度考虑设备的材质选择和采取有效的防腐蚀措施.     

重粉尘环境敞开循环冷却水系统水稳剂的研制

针对重粉尘环境发电厂敞开循环冷却水系统的工艺条 件，通过旋转腐蚀挂片试验、静态阻垢试验、动态污垢热阻及腐蚀速度测试等一系列试验， 研制了其相应的水稳剂.     

循环冷却水中 2507 双相不锈钢微生物腐蚀研究

目的研究2507双相不锈钢在循环冷却水模拟溶液(添加微生物SRB+IOB)中的腐蚀特征,确定其腐蚀机理。方法模拟某炼油厂循环冷却水溶液,采用SEM,EDS和电化学测试等手段分析2507双相不锈钢在SRB+IOB循环冷却水中浸泡不同时间后的腐蚀产物形貌及其电化学腐蚀情况。结果2507双相不锈钢的腐蚀速率很低,属于轻度腐蚀;在循环冷却水模拟溶液中的阳极极化曲线具有明显的钝化区,且钝化膜具有良好的自修复能力;腐蚀倾向随时间增加先增大后减小,腐蚀速率随时间增加先减小后增大。结论 SRB和IOB及其代谢活动与Cl-协同作用是点蚀的主要原因;2507双相不锈钢具有良好的钝化性和耐微生物腐蚀性能。     

油田回注污水对常用管线钢的腐蚀性

通过水质分析和动态挂片试验,应用EDS、SEM、XRD等研究了回注污水对常用管线钢20g、16Mn的腐蚀性.结果表明,在温度T=50℃～70℃及常压下,回注污水对以上材料的腐蚀主要为局部氧腐蚀和氯腐蚀.50℃时,平均腐蚀率(mm/a)为：0.1245(20g)、0.119（16Mn）.70℃时,平均腐蚀率(mm/a)为：0.3105(20g)、0.3185（16Mn）.对其腐蚀机理进行了探讨.       

宝浪油田污水腐蚀影响因素

对宝浪油田污水处理系统污水水质、腐蚀挂片等数据分析,结果表明,该污水处理系统腐蚀严重。为了确定腐蚀影响因素,进行了污水流速、温度、pH等因素对腐蚀速率影响的试验研究。初步确定了这些因素对宝浪油田污水腐蚀影响规律,为日后制定防腐蚀措施可以提供参考。     

胜利油田污水站腐蚀监测与缓蚀剂智能加注系统及其应用

针对胜利油田污水回注系统,采用电化学阻抗腐蚀监测技术实现了油田污水集输管线腐蚀速率的快速测量。基于缓蚀剂加注前、后和外输管线等多点腐蚀监测数据和模糊控制算法,提出了一套腐蚀监测与缓蚀剂智能加注无线解决方案,用于集输管线的在线腐蚀监测与缓蚀剂自适应加注的远程管理。该方案中,由服务器软件根据现场腐蚀速率变化趋势和模糊控制模型,适时发送指令给变频器,进行调整现场缓蚀剂隔膜泵的加注速率。该自动加药系统不仅能有效控制集输管线的腐蚀速率,同时也避免了缓蚀剂的过量加入,降低了污水处理成本。     

火力发电厂循环水系统的腐蚀现状及防护技术

１前言 火力发电是靠燃煤（或油）释放的热能将水加热成蒸汽，以推动汽轮机作功，转化为电能，作完功后的蒸汽经凝汽器冷却后循环使用。蒸汽的冷却是由冷却水系统通过凝汽器完成的。循环冷却水有淡水和海水之分，为了节约用水，冷却水常常循环使用，含盐量逐渐增高。随着含盐量的增高，循环冷却水的腐蚀性就显得更加突出。如何保障循环冷却水系统的安全经济运行对于火力发电厂的正常生产具有重要的意义，本文介绍了以淡水为补充水的敞开式循环冷却水系统的腐蚀及防护技术。 ２循环冷却水系统的腐蚀现状 火力发电厂冷却水系统中循环水管道、…     

循环冷却水污垢垢样中各元素含量的机理解释

垢样中铁元素含量是判定循环冷却水装置腐蚀程度的重要标志.为了满足污垢特性预测的需要,实验设计为动态封闭式循环冷却水系统模拟垢样生成,并在模拟试验期间实时取动态水样检测其中的铁离子含量、微生物数;在线监测pH、溶解氧、腐蚀速率等.在垢样的精准分析中,以JY/T 015-1996等离子体发射光谱分析方法测得的垢样中铁离子、铜离子、有机物含量.结果表明,水中铁离子高,垢样中的铁元素检出值高,表明腐蚀程度也相对高;另外,垢样中的铜离子含量高,垢样中的有机物的含量就低,二者呈负相关.     

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。