不同流动体系中碳钢磨损腐蚀可比性的研究

采用管流式和旋转式两种流动模拟装置，研究了碳钢在单、双相流动海水中的磨损腐蚀。结果表明，在相同流速条件下，两种模拟装置所测得的碳钢流动腐蚀速度很难相同，流速不能准确描述流体流动对材料腐蚀的作用。而材料表面近壁处流体力学参数(表面切应力、传质系数)却与材料流动腐蚀本质相关。在保证动量、质量传递相似的条件下，从表面切应力、质量传递系数等参量入手，研究两种装置中实测的腐蚀速度的可比性和关联性是可行的。碳钢磨损腐蚀机理的研究表明：其腐蚀机制与流动模拟装置无关，在流动海水中溶解氧的传质是腐蚀的主要控制因素。     

多相流动淡水体系中碳钢冲刷腐蚀电化学行为的研究

在含砂淡水流动体系中对HG60碳钢进行了电化学测量,用旋转圆柱电极方法研究了冲刷腐蚀条件下影响20A碳钢阴极行为的两个因素。结果显示,水流速度的提高、固体颗粒物的存在都能使氧的传输加强,提高氧的极限扩散电流,使碳钢的冲蚀情况加剧,在1800－3000r/min（线速度小于2．17m/s)转速条件下,碳钢在0．1mol/L硫酸钠介质中的冲刷腐蚀由氧的扩散控制;当水流速度进一步提高（≥8m/s)时,碳钢的阴极反应可能转变为扩散和活化共同控制。     

低碳钢低温解理断裂应力计算

本文利用弹塑性大应变等参有限元法,对Chacpy缺口和任意裂缝四点弯曲试样的应力应变场进行了计算。并基于S_(co)—解理特征应力物理模型,对低碳钢低温解理断裂应力进行了计算。其计算结果与实验结果相吻合。本文还根据计算和实验结果。对工程塑脆转折温度进行了定义。     

Presence and Absence in ‘Abandoned’ Palestinian Villages

This essay deals with the way Palestinian villages, emptied during the 1948 war when their inhabitants fled or were expelled, were visually preserved in Israeli consciousness. The essay analyses a group of photographs in official Israeli archives that were taken by Israeli photographers between 1948 and 1951. These images, taken for Israeli national propaganda to describe the new Jewish immigrants who had been settled by the new Israeli state in these villages, show how they implement the Zionist world view. In contrast to these purposes, however, reading these institutional photography archives also makes it possible to learn about Palestinian identity before 1948 and gain insight into the Palestinian people, who are missing from these photographs. The essay shows how the manner of reading these archives makes possible the extraction of different layers of meanings.     

金属在液固两相流中的冲刷腐蚀

液固两相流体的冲刷腐蚀行为较单相流体更为复杂,在相同液相介质的情况下,其冲刷腐蚀对材料的破坏程度更为严重。综述了国内外对液固两相流的冲刷腐蚀体系开展的研究,对冲刷腐蚀的过程有了进一步的认识,对冲刷腐蚀的影响规律和危害性进行了论述,从而为材料的选用提供一定的参考依据。     

Influence of the Microstructure on Magnetic Stray Fields of Low-Carbon Steel Welds

This study examines the relationship between the magnetic mesostructure with the microstructure of low carbon steel tungsten inert gas welds. Optical microscopy revealed variation in the microstructure of the parent material, in the heat affected and fusion zones, correlating with distinctive changes in the local magnetic stray fields measured with high spatial resolution giant magneto resistance sensors. In the vicinity of the heat affected zone high residual stresses were found using neutron diffraction. Notably, the gradients of von Mises stress and triaxial magnetic stray field modulus follow the same tendency transverse to the weld. In contrast, micro-X-ray fluorescence characterization indicated that local changes in element composition had no independent effect on magnetic stray fields.     

304不锈钢在盐湖卤水中的腐蚀行为

用腐蚀挂片试验方法研究了304不锈钢在盐湖卤水中暴露2a的腐蚀行为,井运用室内电化学试验方法研究了其电化学行为。结果表明：盐湖卤水浸泡2a后,304不锈钢腐蚀速率为0．0003mm／a,主要表现为点蚀,试样侧面加工缺陷处存在较深的点蚀坑;在卤水中浸泡768h后,304不锈钢表面钝化膜局部被破坏,出现点蚀孔。     

The Frequency Response of Photographic Reproductions in the Presence and the Absence of Diffusion Effects during Development

Observations on the photographic reproduction of fine line, edge and sine-wave test images show that while the spatial frequency or sine-wave response function of the process is independent of image configuration in the absence of chemical diffusion effects this is not always the case in their presence, the response for the high-frequency components being higher for the reproduction of edge and fine-line images than for sine-wave images. A possible explanation of this result and its consequences is suggested.     

Analysis of the Surface Defects in a Hot-Rolled Low-Carbon C–Mn Steel Plate

Journal of Failure Analysis and Prevention - In the present study, a microstructural investigation was conducted on surface defects occurring in a 28 mm thick low-carbon C–Mn steel...     

低碳低合金钢SFHV23B的“意外”氢脆破坏

本文对某大化肥厂气化炉盖材料SFHV23B钢的脆性开裂事故,综合利用机械性能测试、化学成分分析、金相、SEM、电子探针和Auger等现代化手段,进行了深入地分析和讨论,揭示了在现场工况下产生了渗碳,使材料表面层成分由低碳变成高碳、在与环境中H_2的共同作用下,产生了“意外”的典型氢致开裂。     

基于EBSD技术的超低碳IF钢中铁素体晶粒尺寸表征

借助电子背散射衍射(EBSD)技术对超低碳IF钢铁素体晶粒尺寸的表征方法进行了研究与探讨。结果显示,对于具有较强织构的IF钢来讲,铁素体晶粒显示以5°为晶内最大取向差进行晶粒尺寸的测量与统计更为准确,与金相法显示的晶界轮廓基本吻合。利用该表征方法测量晶粒尺寸,不仅可以给出晶粒尺寸的平均值、最大值和最小值,还可以给出晶粒尺寸分布图。     

油气生产与输送过程中冲刷腐蚀的研究进展

冲刷腐蚀是油气生产和输送过程中管道和生产设备的主要失效形式之一,严重影响了油气生产和输送安全,给国家和企业造成了巨大的经济损失.综述了近年来油气冲刷腐蚀的研究现状,探讨了油气冲刷腐蚀的机理;介绍了油气冲刷腐蚀的研究方法,包括现场测试法、室内模拟试验法和数值模拟法;分析了材料因素、环境因素和流体动力学因素对油气冲刷腐蚀的影响机制;重点关注了油气管线中弯头的冲刷腐蚀行为规律.最后,总结了油气冲刷腐蚀防护技术及措施,并对未来的研究方向进行了展望.     

The Kinetic Energy of the Condensate in the Presence of an External Applied

Average quantities can be determined in many-body physics by the virial theorem even in cases when knowledge about the interaction among particles is not complete. Starting from the virial theorem for superconductivity we obtain an expression for the magnetization of two periodic systems, the infinitely extended film of arbitrary thickness under a perpendicular applied field and the bulk superconductor. We show that the kinetic energy of the condensate can be directly retrieved from the magnetization for a large κ type II superconductor or near the upper critical field, in the pinning free (reversible) regime. Isofield kinetic energy lines for low- and high-T _c compounds have striking differences near the critical transition that clearly indicate for the latter case the presence of a unique superconducting condensate below and above the mean field critical temperature.      

Thermodynamics and Kinetic Processes of Polymer Blends and Block Copolymers in the Presence of Pressurized Carbon Dioxide

Environmentally‐responsible materials processing is becoming an important global consideration in a wide variety of technologies, especially those wherein volatile and/or residual organic solvents cannot be tolerated. In this context, polymer processing has benefited tremendously from advances achieved using high‐pressure CO₂ as a viscosity modifier, plasticizing agent, foaming agent, and reaction medium. Pressurized CO₂ is environmentally benign, inexpensive, sustainable, and versatile owing to its gas‐like viscosity and liquid‐like solubility, which can be tuned through judicious choice of temperature and pressure. The addition of high‐pressure CO₂ to homopolymer blends and block copolymers can have a profound impact on polymer thermodynamics and kinetic processes since the number of interacting species increases. As a result, the compressibility as well as plasticization and intermolecular screening effects become non‐negligible. In this work, we review how these factors influence such polymeric systems, and discuss commercial polymer processes and applications that benefit from the use of high‐pressure CO₂.     

Surface Characterization of Hot and Cold Rolled Low-Carbon Steel Strips after Galvanizing and Galvannealing

Surface topography is of paramount interest in science, technology, and industry. Surface characteristics dominate functional applications in the fields of friction, wear, lubrication, fatigue, sealing, joining, reflecting, painting, bearing surfaces, and optical properties. The morphology of surfaces can be studied with the aid of techniques such as contact profiler and atomic force microscopy, among others, as will be discussed in this work. Samples of galvanized and galvannealed low-carbon steel strips were obtained to analyze their roughness. The influence of parameters such as rolling direction and the type of rolling process (hot and cold) and the face (top or bottom) of the sheet was analyzed in samples that were either galvanized or galvannealed in a laboratory simulator. Results show that the processing parameters exert a high influence on surface topography.     

Mechanism of Inhibition of Corrosion of Steel in the Presence of Sulfate-Reducing Bacteria

We consider the electrochemical and microbiological aspects of microbe-induced corrosion of low-carbon steels caused by sulfate-reducing bacteria and its inhibition by organic surfactants. We propose relations that take into account the influence of the main products of the vital activity of sulfate-reducing bacteria (H₂S and HS^–) on the cathodic and anodic reactions of the corrosion process. The evaluation of the adsorption properties of organic surfactants and analysis of their influence on the kinetics of oxidation-reduction reactions enable one to develop high-performance inhibitors of microbe-induced corrosion of steels in aqueous aggressive media containing sulfate-reducing bacteria.     

对40、50轴钢的几点看法

在４０钢车轴断裂失效的模式、原因和统计分析的基础上,对４０钢和５０钢的基本力学性能进行了比较,并对４０钢和５０钢车轴的使用安全性提出了建议。