沿海飞机铝合金结构件腐蚀与防护

综合作者多年的飞机结构修理工作，分析、归纳了沿 海机场飞机典型腐蚀损伤，得出飞机结构腐蚀主要是环形间隙中未加保护的铝合金表面和间隙中的积水而形成的电化学腐蚀.提出缝隙密封等减少结构腐蚀的制造和使用维护过程中的防腐工艺措施.     

SA-178A余热锅炉换热器管失效分析

通过化学成分分析、金相分析、宏观和微观腐蚀形貌观察、腐蚀产物分析以及相关的理论计算后认为，SA-178A低碳钢余热锅炉换热器管道爆裂的主要原因是硫酸盐低温热腐蚀引起的管壁外部严重减薄导致的，蠕变以及管内压力的综合作用加速了管道爆裂过程.     

触变成型镁合金AZ91D在兰州城市大气中的腐蚀行为研究

研究了兰州大气中触变成型镁合金AZ91D的腐蚀行为.结果表明:发生的腐蚀是与降水有关的电偶腐蚀，湿度是影响腐蚀过程的主要因素之一;腐蚀发生在原固相区的α相和液相区的共晶α相，β相作为腐蚀的阴极区;α相表面形成的表面膜和龟裂是α相腐蚀加剧的主要控制因素.腐蚀产物与大气中的腐蚀性气体CO2，SO2有关.     

HDM钢在AZ91DMg合金液中的腐蚀行为

利用扫描电镜和能谱分析等手段研究了HDM钢在AZ91D Mg合金液中的腐蚀行为.结果表明，HDM钢与Mg合金液之间产生了化学反应，生成腐蚀产物层.反应初期，腐蚀层疏松，基本不具有保护性；随着反应的进行，腐蚀层逐渐加厚致密，具有较好的保护作用，减缓了腐蚀速度.HDM钢与Mg合金液之间的反应主要是在钢中的Fe、Mn、Cr、Co和Mg合金液中的Al、Mn之间进行；腐蚀动力学过程可分为快速反应，钝化和稳速反应三个阶段.     

电化学噪声表征7075铝合金的模拟大气腐蚀过程

用电化学噪声表征7075铝合金的模拟大气腐蚀过程，旨在探索电化学噪声方法在航空器腐蚀检测上的应用.用吸附3.5%NaCl电解液的镜头纸紧贴于试样表面以模拟大气腐蚀环境，测试了7075T6铝合金的腐蚀电流、电位随浸泡时间的波动.电化学噪声实验结果显示，腐蚀初期电流波动幅度较小，正负方向幅度相当.腐蚀2h后；电流波动表现为正向锯齿波，幅度增大到0.3 μA左右；6h后电流表现为幅度不等的负向波动.可以预测2 h后铝合金钝化膜的破坏是腐蚀的主要过程，6h后钝化膜的修复则占主导地位.     

2A12铝合金外套螺母裂纹分析

飞机氧气导管2A12铝合金外套螺母在服役过程中出现裂纹。通过外观观察、断口宏/微观观察、金相组织检测、化学成分分析等方法，对外套螺母裂纹的产生环节和开裂原因进行分析。结果表明:外套螺母裂纹为应力腐蚀所致，裂纹呈分叉状，断口具有泥纹花样的腐蚀产物；应力腐蚀裂纹主要应力来源为外套螺母在装配连接过程中产生的周向应力；应力腐蚀裂纹源头主要出现在外套螺母的螺纹前几扣和端面部位；端面变形磨损或螺纹配合磨损引起局部膜层损伤和抗腐蚀能力下降，是导致该处成为应力腐蚀裂纹源头的主要原因。     

某油田掺输管网腐蚀原因分析及防护对策研究

某油田采油厂掺输管网腐蚀严重，通过对其水质和腐蚀产物进行分析，查明了该掺输管网的腐蚀原因.认为结垢及垢下局部腐蚀是该管网腐蚀的主要特征,高氯离子、SRB和硫化氢是诱发垢下局部腐蚀的主要因素.同时还提出了防护对策.     

双相钢在流动中性含砂氯化物中的磨损腐蚀

研究了双相钢在流动含砂的3.5%NaCl溶液中的磨损腐蚀规律,测定、分析了流动体系中的电化学阻抗谱,揭示了双相钢磨损腐蚀过程中电化学的作用及其机制.结果表明,腐蚀电化学因素在磨损腐蚀过程中起主要作用,流体力学因素只是加速了腐蚀电化学过程.阻抗谱在低频区出现一直线段和低频收缩现象,分别是双相钢在磨损腐蚀过程中电极处于自钝化状态,并受离子在钝化膜中的扩散、迁移过程控制和电极表面局部遭受破坏的特征.对于流动体系中电化学阻抗谱的分析,曹氏阻抗理论同样适用.     

Nernst方程在埋地管线腐蚀研究中的应用

应用Nernst方程计算出各可能的腐蚀原电池电极电位，从而判断出引起管线腐蚀的可能的氧化剂，结合腐蚀调查分析出管线腐蚀的主要原因.最后以某管线为实例进行了详细的分析.      

铁素体/奥氏体双相钢在旋转单相流体中腐蚀的数值模拟

引入现代流体力学方法，建立流体力学、传质过程、腐蚀电化学反应的综合数学模型，对双相钢在流动3．5％NaCl水溶液的腐蚀过程进行了数值模拟．探讨了近壁处流体力学参数对双相钢腐蚀过程的作用，模拟结果表明：双相钢的腐蚀主要受阳极过程控制，其中钝化膜中的传质过程是腐蚀的主要控制步骤．计算的腐蚀速度与实测值基本一致,验证双相钢的流体腐蚀机构．     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.