应用冷连轧机板形控制CVC^＋技术的体会

介绍了德国西马克公司板形控制CVC技术的发展,分析了CVC、CVC~＋辊型曲线及现有CVC技术存在的不足,重点介绍CVC、CVC^＋板形控制技术的原理、功能及特点,并对其数学模型和CVC使用中的问题进行了分析。     

纳米多相金属结构尖端分析方法(三)

主要介绍实际最新透射型(TEM)和扫描透射型(STEM)电子显微镜装置现状。     

专利名称：Mo—Mo＋Sj＋Al功能梯度材料及其制备方法

一种Mo—Mo＋si＋Al功能梯度材料及其制备方法，属冶金材料技术领域，用于解决功能梯度材料梯度层薄、微裂纹自愈能力差的问题。特别之处是，     

微生物处理含钒废水中V5+、Cr6+的实验研究

对含钒废水处理现状进行了分析，采用复合功能菌对钒制品废水中V^5＋、Cr^6＋重金属离子进行处理。结果表明：用微生物工艺流程处理含钒废水中V^5＋、Cr^6＋重金属离子技术上可行；V^5＋、Cr^6＋去除率最高达99．9％；出水金属离子浓度达到国家排放标准。     

钙和镁在铸态镍基高温合金中的分布及作用

用化学相分析方法研究了Ca和Mg在铸态镍基高温合金中的分配。用SIMS、STEM、AES等证明了Ca和Mg偏聚于晶界;与氧、硫、磷等杂质相结合形成无害的夹杂物颗粒,净化了合金晶界;进入一次碳化物,球化分散了一次碳化物。基本上弄清了Ca和Mg在高温合金中的分布及存在形式,并讨论了Ca和Mg影响合金热塑性的作用机理。     

对c++中malloc/free和new/delete的探讨

函数nlalloc／free和运算符new／delete是C与C＋＋中进行动态内存分配必不可少的工具。文章从语法、功能以及它们的相同点与不同点等方面介绍了malloc／free和new／delete在内存分配上的应用。     

V-Ti-N微合金化钢中含钛颗粒的特征和行为的研究

本文利用光学金相、电镜(STEM和SEM)及能谱(EDAX)和波谱(WOX)等技术对V-Ti-N钢在铸态、热加工态以及正火状态等各种条件下含钛碳氮化物沉淀颗粒的特征和行为进行了分析和研究。在实验室条件下模拟了连铸坯和钢淀心部的冷却条件,并借助于浇注后冷却至不同温度快速淬火的方法,研究了各温度区间含钛颗粒的形成规律。     

Mg~（2＋）,Ca~（2＋）,Ba~（2＋）离子部分取代对SrAl_2O_4：Eu~（2＋）,Dy~（3＋）晶体结构和发光性能的影响

采用高温固相反应法制备了Sr0.9M0.1Al2O4：Eu2＋,Dy3＋（M=Mg,Ca,Ba）长余辉发光材料,并对其晶体结构、光谱性质、余辉特性进行了分析.X射线衍射测试结果表明,Mg2＋,Ca2＋,Ba2＋离子部分取代SrAl2O4基质中的Sr后,基质晶体结构并没有发生改变.光谱测试结果表明,Mg2＋,Ca2＋,Ba2＋取代后发光材料的激发光谱都是一个从250~450 nm范围内的宽激发带,在266nm,320nm,360nm,416 nm处各有一个激发峰.发射光谱中Mg2＋和Ba2＋的取代使波长出现蓝移,而Ca2＋的取代使波长出现红移.余辉测试结果表明,Ca2＋取代后的余辉时间长于Mg2＋和Ba2＋的取代.     

Tb（Ⅲ）—TPA体系荧光强度的提高及其在分析中的应用

主要研究了 Tb3＋－ TPA－ TPPO(Phen)体系在 TritonX－ 100与乙醇存在下的荧光性质及 Gd3＋、 Y3＋对 Tb3＋－ TPA－ TPPO荧光强度影响。试验表明：在 pH值为 6的溶液中, Tb3＋－ TPA体系的荧光并不见强;在 TB3＋－ TPA体系中加入 TPPO和 Triton X－ 100,并调节溶液的 pH至 4,则 Tb3＋的荧光强度大幅度提高; Gd3＋、 Y3＋对 Tb3＋－ TPA－ TPPO的荧光强度具有明显增强作用。此法用于痕量 Tb3＋的测定,其检出限可达 2× 10－ 9mol/L。     

复合被字句中的“所”与“给”及相关的焦点标记问题

根据标记理论,认为重音是＂焦点的口头标记形式＂,通常所说的＂焦点标记词＂应该属于＂焦点的书面标记形式＂;通过对70部现当代文学作品进行定量分析的方式,考察了＂被＋NP＋给＋VP＂与＂被＋NP＋所＋VP＂这两类格式中虚词＂给＂与＂所＂的隐现规律,得出复合被字句中＂给＂与＂所＂的语法功能;在＂焦点标记＂理论基础上,文章通过论证得出,＂是＂、＂给＂与＂所＂都是焦点的书面标记形式。     

Microstructure Evolution and Precipitation Behavior of 0Cr16Ni5Mo Martensitic Stainless Steel during Tempering Process

The microstructure,morphology of precipitates and retained austenite and the volume fraction of retained austenite in 0Cr16Ni5 Mo stainless steel during the tempering process were analyzed using optical microscope(OM),transmission electron microscope(TEM),X-ray diffraction(XRD)and scanning transmission electron microscope(STEM).The results show that the microstructure of the tempered steel is mainly composed of tempered martensite,retained austenite,and delta ferrite.In the case of samples tempered from 500 to 700 ℃,the precipitates are mainly M_(23)C_6,which precipitate along the lath martensite boundaries.The precipitate content increases with the tempering temperature.During the tempering process,the content of retained austenite initially increases and then decreases,the maximum content of retained austenite being 29 vol.% upon tempering at 600 ℃.TEM analysis of the tested steel reveals two morphology types of retained austenite.One is thin film-like retained austenite that exists along the martensite lath boundary.The other is blocky austenite located on packet at the boundary and the original austenite grain boundary.To further understand the stability of reversed austenite,the Ni content in reversed austenite was measured using STEM.Results show a significant difference in nickel concentrations between reversed austenite and martensite.     

Laser-clad Ni70Al20Cr7Hf3 alloys with extended solid solution of Hf: Part I. Microstructure evolution

Coatings for superalloys for extended service in atmospheres at high temperature are of great interest at present. The addition of reactive elements (RE’s) such as Hf to these coatings has a pronounced effect on their high-temperature oxidation resistance. A laser-cladding technique was used to produce Ni-Al-Cr-Hf alloys with an extended solid solution of Hf in a nearstoichiometric Ni₃Al matrix. A 10 kW CO₂ laser with mixed powder feed was used for the cladding process. Scanning electron microscope (SEM), transmission electron microscope (TEM), and scanning transmission electron microscope (STEM) were employed for studies of microstructural evolution of alloys produced during the laser-cladding process. Microstructural studies reveal the formation of dendrites with a solid solubility of about 11 to 14 wt pct Hf and also a eutectic structure. Convergent-beam techniques and X-ray spectroscopy have been applied to characterize the phases formed during the cladding process.     

镍对Fe-Cu-Ni合金中铜析出行为的影响

 利用透射电子显微镜(TEM)对Fe-Cu和Fe-Cu-Ni合金中铜颗粒的析出形貌及成分进行观察。同时根据Cahn-Hilliard非经典形核理论和Modified Langer Schwartz模型对合金中沉淀的析出过程进行模拟计算。扫描透射电镜(STEM)试验结果表明,镍元素在沉淀核心处浓度很低,而在颗粒-基体界面处存在富集现象,添加元素镍可降低沉淀颗粒的形核功,促进沉淀析出和长大粗化。该试验结果与理论模型预测结果一致。     

Mechanisms of inclusion formation in Al−Ti−Si−Mn deoxidized steel weld metals

The present investigation is concerned with basic studies of the mechanisms of inclusion formation in submerged arc (SA), gas metal arc (GMA), and flux cored arc (FCA) steel weld metals. Theoretical models of deoxidation have been developed to establish a basis for quantitative predictions of important inclusion characteristics, such as volume fraction, size, and chemical composition from knowledge of weld metal chemistry and operating parameters. The relevance of these models has been tested against extensive inclusion data obtained from scanning electron microscope (SEM) and scanning transmission electron microscope (STEM) examinations of a large number of experimental welds containing various contents of aluminum, titanium, silicon, manganese, and oxygen.     

Cyclic deformation behavior of high-purity titanium single crystals: Part II. Microstructure and mechanism

Strain-controlled cyclic tests have been conducted on high-purity titanium single crystals with different orientations. The fatigue mechanisms of the titanium crystals were studied by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). It was found that single slip lines, wavy slip lines, double slip lines, twins, and associated slip lines occurred in differently oriented single crystals. A new type of fractographic morphology, parallel traces, was observed. Dislocation patterns and cyclic twins, as well as the mechanical response, were analyzed. The dependence of the deformation mechanisms on the orientations of the single crystals is discussed.     

Effect of Substructure on Toughness of Lath Martensite/Bainite Mixed Structure in Low-Carbon Steels

The quantitative analysis of substructure in the martensite/bainite mixed structure, which is obtained from low-carbon NiCrMoV steels under different cooling conditions, was made by means of optical microscope (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM), in order to research the effect on toughness. The test results indicate that the toughness of the steel is enhanced with the decrease in the packet and block size under the condition of the same prior austenite grain size mixed with different ratios of martensite and bainite while the lath width is about 0.38 μm. The calculation shows that both the packet and block boundaries have the same hindering effect on crack extension. Furthermore, the effect of the block width on impact energy is much larger than that of the packet. Therefore, the block can be used as microstructural substructure to affect the toughness in low-carbon martensite steels, suggesting that the block size is "the effective grain size" for controlling toughness.     

Heterogeneous Nuclei of Intergrowth Eutectic in Austenite-Bainite Steel Modified by Ce and Al

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Coarsening resistance of M2C carbides in secondary hardening steels: Part III. Comparison of theory and experiment

A model for the coarsening resistance of multicomponent carbides was used to study the effect of Mo and Cr on the coarsening kinetics of M₂C carbides in commercial AF1410 and experimental alloy steels. Experimental studies of coarsening behavior of the carbides in these steels have been made by using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The measured coarsening rate constant agrees with model predictions within a factor of 2 to 3. The coarsening kinetics of M₂C carbides in these alloys is found to be controlled by the volume diffusion of alloying element M. A Cr-Mo alloy steel with the predicted optimum composition showed the slowest coarsening kinetics and highest hardness at long tempering times.     

Root resorption and pulpal changes due to intrusive force

Intrusion has been regarded as a controversial topic in the literature. It is apparent from many studies that excessive forces applied in orthodontic treatment might lead to undesirable results such as circulatory disturbances, pulp degeneration, calcification and even necrosis. This study was performed to observe the reaction of pulp and roots following tooth intrusion. Material consisted of four first premolar teeth of two adult patients. One premolar of each patient was intruded orthodontically and the other premolars were taken as controls. The palatal roots of the experimental teeth were cut and examined in scanning electron microscope (SEM) and the pulps of the teeth were examined in transmission electron microscope (TEM). At SEM examination, root surfaces of intruded teeth showed resorption cavities of different diameters and depths. At TEM examination, vascular degeneration was the main change in the pulps of experimental teeth.