INFLUENCE OF DISSOLVED CARBON CONTENT ON RECRYSTALLIZATION γ TEXTURE IN ULTRA-LOW CARBON DEEP DRAWING STEEL WITH HIGH PURITY

借助三维取向分布函数探讨了高纯超低碳深冲钢板的固溶碳含量对再结晶γ织构的影响，分析了固溶碳与再结晶γ织构及其中的｛１１１｝＜１１２＞和｛１１１｝＜１１０＞织构之间的关系     

CHEMICAL VAPOUR GROWTH OF CARBON WHISKERS ON CARBON FIBERS

The secondary reinforcement,crbon whiskers,may grow on the surface of parent rein-forcement,carbon fibres,by chemical vapour growth from acetylene using Fe salt ascatalyzer.The optimal growing temperature is about 1000℃,and while the concentra-tion of catalytic solution is appropriate,the carbon whiskers may deposite uniformly andlink each other on the parent carbon fibre surface.If the temperature or concentration istoo high,the coarse clusters of carbon may deposite on the fibre surface.The mechanismof carbon whisker growth is believed that the carbon atoms in vapour phase dissolve inthe Fe salt drops over fibres,then the solid carbon grains precipitate on the fibre surface.     

PREPARATION OF MESOPOROUS CARBON BY CARBON DIOXIDE ACTIVATION WITH CATALYST

A mesoporous activated carbon (AC) can be successfully prepared by catalytic activa-tion with carbon dioxide. For iron oxide as catalyst, there were two regions of mesopore size distribution, i.e. 2-5nm and 30-70nm. When copper oxide or magnesium oxide coexisted with iron oxide as composite catalyst, the content of pores with sizes of 2-5nm was decreased, while the pores with 30-70nm were increased significantly. For comparison, AC reactivated by carbon dioxide directly was also investigated. It was shown that the size of mesopores of the resulting AC concentrated in 2-5nm with less volume. The adsorption of Congo red was tested to evaluate the property of the result-ing AC. Furthermore, the factors affecting pore size distribution and the possibility of mesopore formation were discussed.     

PREPARATION AND CORROSION RESISTANCE OF NiP/TiO2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM （environmental scanning electron microscopy） and EIS （electrochemical impedance spectroscopy） measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS （X-ray photoelectron spectroscopy） spectrum, and an anticorrosion mechanism of the composite film was discussed.     

EFFECT OF TRACE ELEMENTS WITH ZERO SELF－INTERACTIONCOEFFICIENT ON CRYSTALLIZATION TEMPERATUREOF IRON CARBON ALLOYS

ＥＦＦＥＣＴＯＦＴＲＡＣＥＥＬＥＭＥＮＴＳＷＩＴＨＺＥＲＯＳＥＬＦ－ＩＮＴＥＲＡＣＴＩＯＮＣＯＥＦＦＩＣＩＥＮＴＯＮＣＲＹＳＴＡＬＬＩＺＡＴＩＯＮＴＥＭＰＥＲＡＴＵＲＥＯＦＩＲＯＮＣＡＲＢＯＮＡＬＬＯＹＳＺＨＡＩＱｉｊｉｅａｎｄＨＵＨａｎｑｉ（Ｄｅｐ...     

INVESTIGATION ON CRYSTALLIZATION KINETICS OF Pd-Cu-Si GLASS

The crystallization kinetics of Pd-Cu-Si glass was studied by means of diferential scanningcalorimetry-Ⅱ.According to Kissinger peak shift meth(?)d and Arrhenius equation,theapparent activation energy was calculated.The crystallization kinetics follows Johnson-Mehl-Avrami equation with n=3.0 within 0.15相似文献   

STUDY OF RAY IRRADIATION ON DIAMOND-LIKE CARBON FILMS

Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (rf) plasma deposition method, γ-ray, ultraviolet (UV) ray were used to irradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were used to characterize the changing characteristics of SP3 C-H bond and hydrogen content in the films due to the irradiations. The results show that, the damage degrees induced by the UV ray on the SP3 C-H bonds are much stronger than that by the r-ray. When the irradiation dose of γ-ray reaches 10×104Gy, the SP3 C-H bond reduces about 50% in number. The square electrical resistance of the films is reduced due to the irradiation of UV ray and this is caused by severe oxidation of the films. By using the results on optical gap of the films and the fully constrained network theory, the hydrogen content in the as-deposited films is estimated to be 10-25at.%.     

ELECTROCHEMICAL FEATURES DURING PITTING CORROSION OF LY12 ALUMINUM ALLOY IN DIFFERENT NEUTRAL SOLUTIONS

The electrochemical features of commercial airfrarne material, Al alloy LY12, in 0.349mol/L neutral sodium chloride (NaCl) and sodium sulfate (NazSO^) solutions were investigated by electrochemical impedance spectroscopy (EIS) and potentiody-namic polarization techniques. The microstructure of the as-tested samples was studied by scanning electron microscopy. The results show that the Nyquist plots of LY12 at different immersion time displayed different features, indicating that the Cl- ions elevate the corrosion rate and inhibit the repassivation of a metastable pit. It also shows that the corrosion product of LY12 formed in SO42- solution isn't easy to dissolve, and it will cover the surface of working electrode in the electrolyte. SEM images indicate that the corrosion apparent area and pit number of LY12 in NaCl solution are greater than that in Na2SO4 solution.     

EFFECT OF BORON ON MICROSTRUCTURE AND PROPERTIES OF Ti-N FILM

ＥＦＦＥＣＴＯＦＢＯＲＯＮＯＮＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＴｉＮＦＩＬＭ①ＹａｎｇＱｉａｏｑｉｎ，ＺｈａｏＬｉｈｕａ，ＸｉａｏＨａｎｎｉｎｇＭａｔｅｒｉａｌＴｅｓｔａｎｄＲｅｓｅａｒｃｈＣｅｎｔｅｒ，ＨｕｎａｎＵｎｉｖ...     

EXPERIMENTAL INVESTIGATION ON GENERATION MECHANISM OF EXPLOSIVE STRESS WAVES

１ＩＮＴＲＯＤＵＣＴＩＯＮＥｘｐｌｏｓｉｖｅｓｔｒｅｓｓｗａｖｅｓａｒｅｑｕｉｔｅｉｍｐｏｒｔａｎｔｉｎｒｏｃｋｆｒａｇｍｅｎｔａｔｉｏｎｐｒｏｃｅｓ．Ｍａｎｙｓｃｈｏｌａｒｓｈａｖｅｉｎｖｅｓｔｉｇａｔｅｄｔｈｅｇｅｎｅｒａｔｉｏｎａｎｄｐｒｏｐａ...     

ELECTROANALYTICAL APPLICATIONS OF CARBOXYL-MODIFIED CARBON NANOTUBE FILM ELECTRODES

The electrochemical behavior of a carboxyl-modified carbon nanotube films was investigated to explore its possibility in electroanalytical applicaton. Cyclic voltammetry of quinone was conducted in 1mol/L Na2SO4, which showed a stable, quasi-reversible voltammetric response for quinone / hydroquinone, and the anodic and the cathodic peak potentials were 0.657V and -0.029V (vs. SCE) at a scan rate of 0.1V.s-1, respectively. Both anodic and cathodic peak currents depended linearly on the square root of the scan rate over the range of 0.01-0.5V.s-1, which suggested that the process of the electrode reactions was diffusion-controlled. Carboxyl-modified carbon nanotube electrodes made it possible to determine low level of dopamine selectively in the presence of a large excess of ascorbic acid in acidic media using derivative voltammetry. The results obtained were discussed in details. This work demonstrates the potential of carboxyl-modified carbon nanotube electrodes for electroanalytical applications.     

一种咪唑啉缓蚀剂在碳钢表面成膜的电化学研究

利用动电位扫描法研究了咪唑啉缓蚀剂MCI在碳钢表 面成膜的耐蚀性能；通过电化学交流阻抗技术.测量了碳钢表面成膜的EIS谱，并提出其特征等效电路.探讨了缓蚀剂在碳钢表面的缓蚀机理.实验结果表明，在高温高压下碳钢表面经咪唑啉缓蚀剂MCI处理成膜后具有很好的耐蚀性能.     

稀土铅钙合金阳极膜的电化学性能研究

采用电化学阻抗谱(EIS)和光电化学方法对比研究了稀土铅钙合金和普通铅钙合金在0.9V,4.5mol/L硫酸溶液中所形成的阳极腐蚀膜的电化学和光电化学性能,同时利用X射线光电子光谱（XPS)对比分析了两种合金阳极膜的组成。结果表明：稀土可使铅钙合金阳极膜中Pb2+ 化合物含量减少,缺陷增加,阻抗降低,有利于消除早期容量损失（PCL）现象。     

预污染处理碳钢腐蚀产物的研究

研究了A3钢以及16Mn钢经预腐蚀处理，置于北京大气腐蚀曝晒站长期曝晒1a,2a后的腐蚀产物的组成，结果表明，尽管预污染气氛不同，曝晒时间不同，但腐蚀产物具有相似的组成，而且主要都由α型羟基氧化铁，γ型羟基氧化铁和δ型羟基氧化铁组成，相同条件下，曝晒1a与2a的腐蚀产物组成基本相同，两种碳钢曝晒后内层腐蚀产物的组成基本相同，但外层有所不同。     

电化学方法研究锈层覆盖下碳钢的腐蚀规律

分别采用失重法与电化学方法(包括极化曲线、线性极化法和电化学阻抗技术)研究了碳钢在海水中浸泡48周的腐蚀规律。结果发现,短期浸泡在海水中的碳钢,表面生成的腐蚀产物薄且疏松,长期浸泡后,锈层逐渐分为两层:外锈层薄且疏松,内锈层厚且致密。短期浸泡,失重法与电化学方法得到的腐蚀规律一致,腐蚀速度逐渐减小并且数值相近,此时电化学方法可以用来准确的估算碳钢的腐蚀速度。长期浸泡,电化学方法测定的腐蚀速度转为逐渐增大,偏离了失重结果,并且锈层越厚偏差越大,此时电化学方法会过高估算腐蚀速度。     

不同湿度土壤中硫酸盐还原菌对碳钢腐蚀的影响

利用微生物分析、失重法、交流阻抗测试技术、扫描电镜及表面能谱等方法，研究了在不同湿度的同一种土壤中，硫酸盐还原菌对碳钢腐蚀的影响规律。结果表明，土壤湿度对菌类生长的影响是显著的，硫酸盐还在菌随着湿度的提高呈递增趋势；在相同的湿度下，接菌土壤中A3钢腐蚀速率和点蚀深度都明显大于灭菌土壤，说明硫酸盐还原菌加速了A3钢在土壤的中的腐蚀；随着含水量的增大，A3钢腐蚀速率首先增大，当土壤含水量增大到15%－20%，腐蚀速率达到最大，然后腐蚀速率随着湿度增大而趋于减小；最大腐蚀深度出现在土壤含水量为15%左右时。　 碳钢 土壤湿度 硫酸盐还原菌 微生物腐蚀     

N80油套管钢转化膜的电化学性能研究

利用交流阻抗技术(EIS)研究了N80油套管钢在0.5 mol/L NaHCO3溶液中所成转化膜的电化学性能,用莫特－肖特基曲线分析了成膜电位、测试频率及Cl-浓度对转化膜半导体性能的影响.结果表明：转化膜呈n型半导体特征;随成膜电位增加,膜的容抗和施主密度减小;随Cl-浓度增加,膜的容抗和施主密度增加,膜的点蚀加剧.     

碳含量和浸泡时间对碳钢热带自然海水腐蚀产物中细菌组成的影响

为了深入探讨海洋微生物对碳钢的腐蚀机理,通过细菌的分离鉴定方法,研究了不同碳含量碳钢在自然海水中浸泡不同时问后腐蚀产物中的细菌组成。结果表明不同碳钢每克表面刮取物中需氧菌及兼性厌氧菌的数量均在浸泡时间为91d时达最大值,而硫酸盐还原菌的数量在浸泡时间为184d时达最大值。铁细菌和硫细菌的变化不明显。不同碳钢,除7d实验周期外,随碳含量增加,腐蚀产物中需氧菌及兼性厌氧菌有增加趋势,而硫酸盐还原菌却存在降低趋势。需氧菌及兼性厌氧菌主要由两个菌属的细菌组成,即假单胞菌属和弧菌属,当浸泡时间达1a时,还出现大量黄杆菌。从各个菌属所占比例可见,碳钢腐蚀产物中菌群初期主要由需氧菌组成,随着浸泡时间延长,兼性厌氧菌开始占据主要地位。铁细菌主要是由瑙曼氏菌属和鞘铁菌属组成。不同细菌在生长过程中对氧的需求与消耗及代谢产物的差异,会对碳钢的腐蚀过程产生不同的影响。     

预污染处理对碳钢大气腐蚀的影响

通过对北京和江津曝露站3个钢种的预污染样品大气腐蚀失重数据及北京曝露站腐蚀产物组成的分析，讨论了不同污染预处理对碳钢大气腐蚀的影响。结果表明：曝露1年和2年的碳钢在江津地区的腐蚀速率均远远高于北京的腐蚀速率；不同污染预处理对3种碳钢后期腐蚀的影响有所差异，但差别不大，其中NO2预污染处理对这3种碳钢的影响最大；尽管预污染气氛不同，曝露时间不同，但腐蚀产物具有相似的结构，而且主要都由α型羟基氧化铁和γ型羟基氧化铁组成．     

氯化物熔盐中Nd^3＋在液体Ga电极上还原的电化学行为

本文利用循环V-A法(CV)研究了Nd~(3+)在液体Ga电极上还原的电化学反应动力学。结果表明,Nd~(3+)在Ga电极上的还原是分步进行的。第一步在较高的电位扫描速度下为扩散控制的可逆电荷传递反应,即Nd~(3+)+e?Nd~(2+);在电位扫描速度较低时,随后的化学反应为第一步反应的控制步骤,即Nd~(3+)+e?快Nd~(2+)+mCl→慢NdCl_m~(2-m)。第二步为不可逆的电荷传递反应,即沉积的金属Nd与Ga合金化,Nd~(2+)+2e→Nd(Ga)。估算了该反应的标准反应速度常数为7.0×10~(-3)cm/s。