盐在铸造中的应用及其局限

本文综述了盐在铸造中的应用及其局限性，提出了一些解决途径。这些途径的有效性还有待于进一步研究。     

苛化渣对浸出渣的影响探讨

根据浸出原理和试验研究结论，论述了苛化渣对浸出渣的影响，探讨了试验结论与生产出现异常的原因，提出了解决问题的途径。     

从酸锂渣中制取活性白炭黑

利用酸性锂渣中的有效成分硅，研制活性白炭黑的实验方法。讨论了制备过程中的三个关键实验条件的控制。对研制成功的产品进行了性能测试，并与国内外的活性白炭黑产品标准进行了比较。结果表明，在主要性能指标上基本达到了活性白炭黑的标准。该产品的研制成功，为锂渣的综合利用又开辟了一条新的途径。     

Nb-V复合微合金化对60Si2MnA弹簧钢耐腐蚀性能的影响

采用中性盐雾加速腐蚀试验和电化学试验,研究了添加0.024Nb-0.12V(wt%)微合金对60Si2MnA弹簧钢耐腐蚀性能的影响.结果表明,Nb-V复合微合金化降低了弹簧钢的腐蚀速率,提高了弹簧钢在5wt%NaCl水溶液中的点蚀电位,是一种经济有效的显著改善弹簧钢耐腐蚀性能的途径.     

可溶性盐对混凝土材料物理侵蚀的研究评述

阐述了混凝土盐结晶物理侵蚀破坏的机理及其破坏特征,介绍了国内外混凝土抗盐结晶破坏的试验方法、评价参数以及影响混凝土盐结晶侵蚀破坏的主要影响因素.提出,通过研究探讨有害离子在混凝土中的传输过程、盐溶液在混凝土中的结晶动力学原理,以及改进试验方法等途径,进一步完善混凝土抗盐结晶破坏的试验方法及评价指标.     

浅析阴床中混入阳树脂的途径、危害、预防及处理措施

介绍实际生产中阳离子进入阴床的途径、危害性；如何判断阳离子进入阴床；如何预防阳离子进入阴床；以及阳离子进入阴床后如何处理。     

A2A受体-EETs途径在盐敏感性高血压治疗中的作用

激活大鼠腺苷2A受体(A_2AR)可使表氧化酶活性增强,从而提高环氧二十碳三烯酸(EETs)的水平,因EETs有扩张肾血管、降血压等作用,故A_2AR-EETs途径有抗升压作用。通过盐敏感性高血压遗传模型Dahl盐敏感性(Dahl SS)大鼠和Dahl盐抵抗性(Dahl SR)大鼠的相关实验得知,高盐喂养的Dahl SR大鼠,其腺苷水平及肾脏对腺苷的反应性均提高,使其表氧化酶活性和EETs的水平升高,因而引发更加明显的肾血管舒张反应,即Dahl SR大鼠可通过上调A_2AR-EETs途径来调节盐负荷时的血压水平;而Dahl SS大鼠却无上述调节能力。因此在盐负荷时上调Dahl SS大鼠的A_2AR-EETs途径,有利于治疗盐敏感性高血压。     

用N-C共渗+氧化工艺提高煤矿机械零件的耐蚀性

针对井下煤矿机械腐蚀严重的现状，将低温盐浴N-C共渗 氧化工艺用于煤矿机械零件的表面处理，重点介绍该工艺用盐的研制。并对处理件进行了耐蚀试验，结果表明，该工艺处理试件较镀锌，镀铬件耐蚀性成倍提高。     

高温海洋环境下过渡金属基合金的腐蚀与防护研究进展

综述了高温海洋腐蚀环境的类型,以及各类合金在不同环境下的腐蚀失效机理。重点考察了Fe、Ti、Ni基合金内部的主要元素在高温下的扩散行为,及其与侵蚀性离子之间的交互作用。从盐雾腐蚀以及熔融热腐蚀2个角度,讨论了化学/电化学反应发生的可能性。基于氧化腐蚀过程中复合氧化膜的形成过程,总结了氧化膜与侵蚀性离子以及杂质气体的再作用机理,明确了保护性氧化膜和非保护性氧化膜的类型。从合金化的角度,揭示了Cr、Al等元素对防腐性能提升的关键作用,指出了材料计算在高温海洋环境的潜在应用价值。最后归纳了高温海洋环境下的涂层防护手段和材料体系,其中结构稳定性和界面反应问题是涂层材料研究的重点。在未来研究方向上,指出应该重点关注腐蚀过程中活性元素的交互作用以及钝化膜的形成机理,筛选有效防护元素。利用氧化、盐雾等多种腐蚀条件,依托构效关系进行涂层优化,形成系统的海洋高温涂层防护方案。高熵合金涂层作为新兴体系在高温防护上的应用具有研究价值。     

伊朗佳佳姆铝厂蒸发试车问题的解决

伊朗佳佳姆铝厂的PU18——蒸发单元，由于设计原因，经捷克和俄罗斯等多国专家组试车均未成功。2003年3月，沈阳铝镁设计研究院和山西铝厂的工程技术人员在分析了蒸发单元的问题后，通过改变操作工艺条件．解决了循环系统中碳碱越来越高，以至于高压溶出的试车不能进行的问题。     

The Influence of Hydrocarbonate Ions on the Anodic Behavior of Aluminum at Different Temperatures

The influence of thermal conditions on the anodic behavior of aluminum in sodium hydrocarbonate solutions of various concentrations was studied. The concentration and temperature limits of local activation in the studied systems are established. The effect of the thermal activation of self-dissolving metal is found.     

The beneficial effect of ruthenium additions on the passivation of duplex stainless steel corrosion in sodium chloride solutions

The effect of varying ruthenium contents of 0.00, 0.14, 0.22, and 0.28% on the corrosion of 22%Cr-9%Ni-3%Mo duplex stainless steel (DSS) after different immersion intervals in 3.5% NaCl solutions has been investigated. The study was carried out using open-circuit potential, potentiodynamic cyclic polarization, chronoamperometry, electrochemical impedance spectroscopy, and weight-loss measurements. Particular attention was paid to the effect of Ru on the pitting corrosion of DSS in the chloride solutions. Electrochemical measurements indicated that the presence of Ru passivates the DSS alloy by decreasing its corrosion parameters. Furthermore, it shifts the corrosion and pitting potentials to more positive values. This effect was found to increase with increasing Ru content and also with increased immersion time of the alloy in the chloride solution before measurements. Weight-loss time data after varied exposure periods (4-20 days) showed that the weight-loss and corrosion rate of DSS significantly decrease with increasing Ru contents.     

A study of the effects of inhibitive and aggressive ions on oxide-coated aluminium using secondary ion mass spectrometry

A Cameca Ion Analyser has been used to examine aluminium surfaces, supporting barrier-type anodic films ca. 720Å thick, after natural immersion for 1–25 h in 1M chloride and chromate/dichromate solutions of varying pH, and neutral 1M phosphate solution. In chloride solutions, chloride is present on the film surface, but not within the film material per se, within the limits of measurement. The degree of film thinning is governed by pH, being more pronounced in alkaline than acid solutions. In chromate/dichromate solutions, chromium uptake occurs by two distinct mechanisms. The first is associated with relatively rapid chromate/dichromate reduction to Cr₂O₃, probably hydrated, within flaws in the anodic film. The second is associated with a more gradual direct chromate/dichromate anion entry into the bulk material probably through the intercrystalline regions in the film, ultimately resulting in film thinning, even in neutral solutions. In phosphate solutions, phosphate anions penetrate and thin bulk anodic alumina in a similar manner to chromate/dichromate anions. The results are interpreted on the basis of the differing surface chemical properties of the various anions in relation to bulk alumina.     

Internal Friction and Grain Boundary Viscosity of Silver and Binary Silver Solid Solutions

Measurements have been made of the variation of internal friction with temperature for spectroscopically pure silver, and for a series of solid solutions of silver with cadmium, indium, and tin, using a Ke-type torsion pendulum apparatus. Some experiments have also been made to investigate the effect of nonmetallic impurity on grain boundary relaxation in silver. The effect of the alloying elements is to increase the grain boundary viscosity, and to raise the activation energy for grain boundary relaxation from 22,000 cal per mol for pure silver to 43,000 cal per mol for the solid solutions; the same value being obtained, within the limits of experimental error, for all the alloying elements and solute concentrations investigated. Results of the experiments show exactly the same trend as those obtained previously for a similar series of copper solid solutions. They are in agreement with the general theory of grain boundary relaxation developed by Zener and Ke, but do not seem to be in agreement with either of the mechanisms so far put forward to explain grain boundary slip.     

Susceptibility of stainless steel alloys to crevice corrosion in ClO2 bleach plants

Stainless steels, including duplex stainless steels, are extensively used for equipment in pulp bleaching plants. One serious corrosion problem in chlorine dioxide bleach plants is crevice corrosion of stainless steels, which is frequently the factor that limits their use in bleach plants. Crevice corrosion susceptibility of alloys depends on various environmental factors including temperature, chemical composition of environment and resulting oxidation potential of system. Upsets in the bleaching process can dramatically change the corrosivity of the bleaching solutions leading to temperatures and chemical concentrations higher than those normally observed in the bleach process. When the environmental limits are exceeded the process equipment made of stainless steel can be severely affected. Environmental limits for crevice corrosion susceptibility of eight stainless steel alloys with PRE numbers ranging from 27 to 55 were determined in chlorine dioxide environments. Alloys used in this study included austenitic, ferritic-austenitic (duplex), and superaustenitic stainless steels. The performance of the different stainless steel alloys mostly followed the PRE numbers for the respective alloys. The 654SMO alloy with the highest PRE number of 55 showed the highest resistance to crevice corrosion in this environment. Under the most aggressive chlorine dioxide bleach plant conditions tested, even alloys Nicr3127 and 654SMO with PRE numbers 51 and 55 respectively were susceptible to crevice corrosion attack. The two factors that seem to contribute the most to crevice corrosion and pitting in the investigated environments are temperature and potential.     

The Internal Oxidation of Ternary Alloys II: The Coupled Internal Oxidation of the Two Most-Reactive Components Under Intermediate Oxidant Pressures

The kinetics of the coupled internal oxidation of the two most-reactive components in the scaling of ternary alloys under oxidant pressures below the stability of the oxide of the most noble component are examined using a number of simplifying conditions which allow to develop an approximate analytical treatment. The precipitation of the two oxides may occur either at a single front or at two different fronts of internal oxidation. The former case corresponds to a unique solution for all the parameters involved in the process. On the contrary, the existence of two fronts of internal oxidation yields a finite range of possible solutions for the oxidation kinetics as well as for all the other relevant parameters. Even though the present treatment does not allow to predict which solution will be adopted by a real system, it is possible to set limits to the values of the parameters yielding physically-acceptable solutions. After considering a general case, the treatment is applied to a real system already examined experimentally.     

The protection potential of aluminium

The corrosion behaviour of aluminium is investigated in chloride solutions at potentials below the critical pitting potential. Potentiodynamic and steady-state polarization data are presented and analyzed. Pit propagation is shown to continue as the applied potential drops below this critical value. The dissolution front shifts from macroscopic pits to more occluded, microscopic sites, which are known to branch out from the main pits in the form of crystallographic pits and tunnels. The protection potential is shown to be ca. 100 mV more active than the critical pitting potential and appears to be independent of the extent of pit propagation within the limits of experimental error. Polarization data are interpreted in terms of metal dissolution kinetics and diffusion. Results are compared to the available data for steel.     

Thermodynamic database development-modeling and phase diagram calculations in oxide systems

The databases of the FactSage thermodynamic computer system have been under development for 30 years. These databases contain critically evaluated and opthnized data for thousands of compounds and hundreds of multicomponent solutions of solid and liquid metals, oxides, salts, sulfides, etc. The databases are automatically accessed by user-friendly software that calculates complex multiphase equilibria in large multicomponent systems for a wide variety of possible input/output constraints. The databases for solutions have been developed by critical evaluation/optimization of all available phase equilibrium and thermodynamic data. The databases contain parameters of models specifically developed for different types of solutions involving sublattices, ordering, etc. Through the optimization process, model parameters are found which reproduce all thermodynamic and phase equilibrium data within experimental error limits and permit extrapolation into regions of tempea＇ature and composition where data are unavailable. The present article focuses on the databases for solid and liquid oxide phases involving 25 elements. A short review of the available databases is presented along with the models used for the molten slag and the solid solutions such as spinel, pyroxene, olivine, monoxide, corundum, etc. The critical evaluation/optimization procedure is outlined using examples from the Al203-SiO2-CaO-FeO-Fe2O3 system. Sample calculations are presented in which the oxide databases are used in conjunction with the FactSage databases for metallic and other phases. In particular, the use of the FactSage module for the calculation of multicomponent phase diagrams is illustrated.     

Untersuchungen zum SwRK-Verhalten des unlegierten Stahles Ck 45 in chloridionenhaltigen wäßrigen Medien

Corrosion fatigue behaviour of steel Ck 45 in aqueous solutions containing chloride ions The fatigue behaviour of carbon steel Ck 45 (comparable to AISI 1045x) is investigated for cyclic tension and rotating bending load with a frequency of 25 Hz. The fatigue limits under cyclic tension load in air are 410 N/mm² for smooth specimens and 290 N/mm² for notched specimens. For rotating bending load a value of 200 N/mm² is found for smooth specimen. The fatigue limits for N = 10⁷ in two different environments (0.3% and 3% NaCl-solution) reach only 37–57% of the according values in air. Cathodic protection of smooth specimens causes an improvement to 95% of the air fatigue limit. The evaluation of the free corrosion potential for all corrosion fatigue tests and the appearence of fracture show typical attributes of corrosion fatigue in the active state.     

Electrochemical behavior of titanium‐tantalum alloys in sulfuric acid solutions

Titanium exhibits a good corrosion resistance in oxidizing acids and neutral media but it is severely attacked in reducing acids. On the contrary, tantalum presents an excellent resistance in both oxidizing and reducing acids, but its high cost limits its use to very aggressive conditions. The titanium‐tantalum alloys are promising materials for use in reducing acids, due to their lower cost and density when compared to tantalum, and their higher corrosion resistance when compared to titanium. Titanium‐20, 40, 60 and 80 wt% tantalum alloys were prepared by arc‐melting and their microstructures were characterized by scanning electron microscopy and X‐ray diffractometry. Their electrochemical behaviors were studied in 20 to 80 wt% sulfuric acid solutions at room temperature, using open‐circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy. Different behaviors were observed depending on the tantalum content and acid concentration. A clear tendency of increase in corrosion resistance with the increase of tantalum content is observed, especially in 80 wt% sulfuric acid solutions.