乙烯基酯树脂鳞片材料在火电厂氨法烟气脱硫系统中的应用

结合神木县洁能综合利用发电厂一期氨法脱硫(FGD)系统防腐蚀实例,介绍了乙烯基酯树脂鳞片材料VEGF的防腐蚀施工方法、施工过程工艺要求、检测手段等;对几种常用防腐蚀形式进行性价比分析。为乙烯基酯树脂鳞片材料在火电厂氨法FGD系统中的推广应用提供参考借鉴。     

氨法脱硫装置中的防腐蚀形式技术探讨

本文介绍了氨法脱硫装置(FGD)中的腐蚀特点,以及针对性地对最常见的防腐蚀形式(VEGF鳞片材料和整体玻璃钢设备)的关键技术进行了分别探讨和研究,重点分析了鳞片材料在氨法脱硫装置中的失效原因和可能,并据此重点地提出防腐蚀技术建议(包括防腐蚀结构和方式)。     

浅析火力发电厂湿法脱硫后烟囱腐蚀现状及防护

火力发电厂湿法烟气脱硫(FGD)后烟气对烟囱造成腐蚀的现象,给电厂的安全运行造成严重的影响。通过分析湿法脱硫后烟囱防腐材料现状存在的问题,对烟囱腐蚀机理需要考虑的因素进行了探讨,最终对烟囱防腐材料的选择、设计、施工和运行等方面提出了建设性意见。     

VEGF鳞片复合材料在脱硫烟囱中应用的可行性研究

本文介绍了鳞片复合树脂胶泥的特点,以及目前国内电厂烟囱的实际运行情况,讨论了VEGF鳞片复合材料在脱硫烟囱中应用的技术可行性,并就VGEF在烟囱防腐蚀应用中可能采用的技术措施进行了试验表征和分析.     

氨法脱硫硫酸铵浆液腐蚀及防护对策

本文针对氨法脱硫硫酸铵浆液腐蚀现状,对硫酸铵浆液的腐蚀机理进行了分析,得出氯离子点腐蚀、硫酸盐和亚硫酸盐结晶腐蚀以及硫酸铵浆液固体颗粒的冲刷磨损是硫酸铵浆液腐蚀的主要形式。本文通过对橡胶衬里、玻璃钢、合金钢等常用防腐材料的使用范围和施工工艺的对比分析,提出了氨法脱硫工艺中浆液防腐材料的选择标准和硫酸铵浆液腐蚀的防护及控制措施。     

非金属衬里材料在烟气脱硫装置上的应用

催化裂化再生装置中产生的烟气是炼油企业污染物的主要来源。根据国家环保标准的要求,炼厂必须采用烟气脱硫装置(FGD)来控制二氧化硫的排放。烟气脱硫装置所处腐蚀环境极为恶劣,若不采取有效的防护措施,将影响整个系统的安全稳定运行。烟气脱硫装置如果整体采用耐蚀合金材料,价格昂贵。介绍了适用于烟气脱硫装置的几种非金属衬里及其性能和应用区域,包括橡胶衬里、玻璃鳞片树脂衬里、耐蚀胶泥、耐蚀砖板衬里、整体玻璃钢等常用非金属衬里,以及聚脲、纳米复合涂料等新型高性能防腐蚀涂料等。橡胶衬里的耐化学腐蚀性和抗介质渗透性较好,但耐温性差,一般用于机械负荷大而内部环境温度较低的区域,如吸收塔内部、浆液系统和烟道。玻璃鳞片树脂衬里的综合性能较好,被广泛应用于烟道、吸收塔等烟气脱硫装置的各个区域。玻璃钢衬里多用于脱硫系统中的输送管道和吸收塔内喷淋管道等部位。胶泥和耐蚀砖板衬里是应用较早的防腐蚀技术,其抗冲击性能差。聚脲和纳米复合涂料是重防腐蚀涂料,是FGD装置腐蚀防护的新技术,虽然在炼厂脱硫装置中有一些应用,但其使用效果还有待证明。     

脱硫后烟囱内壁防腐蚀材料选择和施工方法

电厂湿法脱硫后,烟囱内部的腐蚀状况非常恶劣。本文介绍了脱硫后烟气的腐蚀性,并介绍了适合钢筋混凝土烟囱改造的四种防腐内衬材料,即发泡耐酸玻璃砖、VEGF玻璃鳞片胶泥、SL300特种耐酸胶泥和防腐涂料。对这四种材料的优缺点、使用方法、实际应用状况等分别进行了介绍,并对多种烟囱防腐蚀措施的经济性进行了比较。     

上海研发出可替代进口的耐腐蚀新材料

最近，上海富晨化工有限公司自主研发成功一种VEGF玻璃鳞片胶泥的耐腐蚀材料。目前，VEGF鳞片胶泥已替代进口产品，在国内外的高温烟囱、脱硫装置（FGD）中得到了大量的应用。VEGF玻璃鳞片胶泥是一种高固体含量的重防腐蚀和超重防腐蚀涂料，采用具有高黏结性和延长率的乙烯基树脂、玻璃鳞片及一些其他材料加工而成，可用于一些重防腐蚀耐高温的场合，如高温烟囱、脱硫装置等。目前，日本、美国等国家均采用这种材料。     

双马来聚酰亚胺复合料的制备及研究

要:本文合成了双马来聚亚酰胺预聚物,以它作为基体树脂,以短切碳纤维为增强材料,加入增韧改性剂,制备了性能优良的复合材料.经过耐温耐酸测试,其耐温性和耐酸性优良,适合用作脱硫烟囱防腐材料.     

电厂双曲线冷却塔的新型防腐蚀工艺

介绍了防腐蚀防渗材料"优止水"在某热电厂双曲线自然通风冷却塔上的防腐蚀应用.对无机类防腐材料和环氧类有机防腐材料进行了比较,对于混凝土防腐防渗工程无机防腐蚀新材料更为适用.     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.