Cl~-浓度对HPB300钢筋在模拟混凝土孔隙液中腐蚀行为的影响

采用自然腐蚀、线性极化、动电位极化、SEM扫描电镜和X射线衍射等方法研究了模拟混凝土孔隙液中Cl-含量对HPB300钢筋腐蚀行为的影响。结果表明,Cl-是引发钢筋锈蚀的重要因素,随着Cl-浓度增加,自然腐蚀电位逐渐负移,当Cl-摩尔浓度达到0.25mol/L时,自腐蚀电位基本不受Cl-浓度影响;线性极化电阻Rp逐渐减小;动电位极化阳极区钝化区电位范围逐渐变窄,过钝化电位由0.6V(SCE,下同)左右逐渐负移至-0.3V左右;腐蚀产物主要为FeO(OH)和FeCl2,产物膜孔隙率减小,微观形貌由片状变为块状。     

高纯锌参比电极电位稳定性研究

采用电化学方法研究了氯离子浓度、温度、阳极极化电流及三者间相互协同作用对99.9999%高纯锌参比电极电位稳定性的影响。结果表明,常温(25℃)下氯离子浓度越高,电极的稳定电位越负;在海水中,偏离25℃,温度升高或降低时,电极电位都会负移,当温度达到50℃时,锌上沉积的腐蚀产物结构改变使锌的电极电位正移;海水温度在0~25℃,阳极极化电流<5μA/cm2,高纯锌具有良好的电流负载能力。     

含重铬酸根硫酸溶液中磁场对铁自腐蚀状态及极化电阻的影响

铁在含有一定浓度重铬酸根的硫酸中,自腐蚀状态下的阴极反应速率受重铬酸根阴极还原电子转移过程与扩散过程共同控制．外加磁场使铁的自腐蚀电位正移,且电位正移幅度随重铬酸根浓度增加而增大．在没有外加磁场时的自腐蚀电位下进行恒电位极化时,外加磁场后会出现阴极电流,磁致阴极电流随重铬酸根的浓度增大而显著增大．外加磁场会使含有一定量重铬酸根的硫酸溶液中铁的极化电阻显著下降．通过对磁场作用进行模型化,分析了磁场作用的动力学机理．磁场对阴极扩散过程的加速作用导致了自腐蚀电位正移及磁致阴极电流,而磁场引起自腐蚀电位的正移是引起极化电阻减小的主要原因．     

Monel(400)合金在NaCl溶液中的电化学腐蚀行为

采用动电位极化扫描法、交流阻抗法对Monel(400)合金在不同浓度NaCl溶液中的腐蚀行为进行研究,结合SEM图对合金表面形貌进行分析。结果表明,合金在低浓度时腐蚀电流小,腐蚀速度慢;在高浓度时,电极电位负移,腐蚀电流增大,腐蚀速度加快。在交流阻抗谱中,高频区为电荷传递控制,低频区为扩散控制,出现了明显的Warburg阻抗效应。当NaCl溶液浓度增大时,极化电阻减小,故腐蚀行为增强。     

平整液对防锈油防护性能的影响

采用丝束电极研究了平整液对防锈油防护的影响。研究表明,涂油丝束电极在浸泡初期,随着浸泡时间的延长,腐蚀电位平均值发生一定程度的正移。当腐蚀电位平均值达到最大值时,随着浸泡时间的工,腐蚀电位开始发生负 ,这一过程与油膜下发生的金属腐蚀过程有关。平整液对防锈油防护性能的影响表现在对涂油丝束电极腐蚀电位平均值及其方差随油膜下金属腐程度的变化上,经过比较,发现ＳＰ３平整液不影响涂油丝束电极腐蚀电位的分布,     

防锈剂的添加量对防锈油膜电化学不均匀性的影响

采用丝束电极方法研究了防锈油防锈剂的添加量对防锈油膜不均匀性的影响.结果表明:防锈剂的添加量不影响防锈油膜腐蚀电位分布和阳极极化电阻Ra分布所遵从的分布规律;但对防锈油膜腐蚀电位的分布区间和极化电阻分布区间具有很大的影响.而且,随着防锈剂的增加,阴极极化电阻Rc分布从不连续二项分布转变为连续正态分布.     

防锈油膜失效之前的电位变化

采用丝束电极研究防锈油膜失效之前的电位变化,结果表明,防锈油膜失效之前,涂油丝束电极腐蚀电位在（－０．２￣０．３Ｖ ｖｓ ＳＣＥ）范围内分布,呈现一定程度的不均匀性,防锈油膜失效之前,涂油丝束电极腐蚀电位随着浸泡时间而发生变化,在浸泡初期,随着浸泡时间的延长,腐蚀电位分布发生一定程度的正移,当腐蚀电位分布达到最大值时,随着浸泡时间的延长,腐蚀电位开始发生负移。防锈油膜失效之前,涂油丝束电极腐蚀电位     

涂油碳钢电极上电化学参数的分布规律

本文采用丝束电极研究了涂油碳钢电极上电化学参数的分布规律.结果表明,涂油碳钢电极的腐蚀电位分布服从不连续二项分布,涂油碳钢电极的阳极极化电阻由不连续二项分布向指数分布和对数正态分布转变,涂油碳钢电极的阴极极化电阻则由不连续二项分布,对数正态分布转变.基础油中加入石油磺酸钡,可以减少腐蚀电位在低电位区分布,减少或消除涂油碳钢电极的极化电阻在低阻区的分布,并使相应的化学参数分布均匀性得到改善.     

防锈油的流平温度对防锈油膜电化学不均匀性的影响

采用丝束电极研究了防锈油涂覆工艺中的流平温度对防锈油膜不均匀性的影响，研究表明，流平温度不影响防锈油膜腐蚀电位分布的不均匀性及其分布规律；流平温度对极化电阻分布规律有一定的影响。随着油溶性缓蚀剂浓度的增加，防锈油膜的腐蚀电位分布和阳极极化电阻（Ra)分布服从不连续二项分布，阴极极化电阻（Rc)分布从不连续二项分布向连续二项分布及对数正态分布转变。研究说明，流平温度高有利于改善防锈油膜的腐蚀电位和极化电阻的分布。     

含重铬酸根硫酸溶液中磁场对铁自腐蚀状态及极化电阻 …

铁在含有一定浓度重铬酸根的硫酸中,自腐蚀状态下的阴极反应速率受重铬酸根阴极还原电子转移过程与扩散过程共同控制,外加磁场使铁的自腐蚀电位正移,且电位正移幅度随重铬酸根浓度增加而增大,在没有外加磁场时的自腐蚀电位下进行恒电位极化时,外加磁场后会出现阴极电流,磁致阴极电流随重铬酸根的浓度增大而显著增大,外加磁场会钤吸一定量重铬酸根的硫酸溶液中铁的极化电阻昱著下降,产场作用进行模型化,分析了磁场作用的动力     

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.     

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.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.