快速引镀覆铜导线技术

快速引镀覆铜技术是根据电化学原理,采用牵引的方式使被镀钢丝连续通过电镀槽,在其表面按要求快速沉积一定厚度铜镀层,而形成铜包钢丝的工艺过程。技术包括镀液、工艺、设备、镀后加工处理和质量监控与检测,是一个完整的技术体系,已经形成工业化生产。 钢心覆铜导线又称为铜包钢导线,它是一种复合导体材料,也是目前导体材料研究开发的重要方向。     

主接地网材料的选择及应用

结合当地土壤地质条件,基于寿阳220 k V及110 k V变电站的大量数据分析,通过对铜接地网、铜覆钢接地网、镀锌扁钢接地网等常用接地材料进行合理性计算和分析。通过计算结果可知,本工程选用-80mm×10 mm镀锌扁钢为主接地网材料,满足腐蚀与热稳定的要求。结合考察在昌吉地区工程中镀锌扁钢均能满足规范要求,工程最终选用镀锌扁钢为主接地网材料。     

电气防雷接地技术在大型工程中的应用

受土质等条件影响,防雷接地电阻常偏高,不利于散流; 角钢接地极,易被腐蚀,接地电阻随时间变化大。在某钢厂防雷技术中,使用降阻剂; 采用新型铜包钢及合理的接地方式等措施。系统使用结果表明,使用降阻剂改良土壤,接地电阻控制在3.6 Ω左右; 用铜包钢接地极,1年后其阻值变化0.1 Ω,接地电阻几乎没有变化,性能稳定。     

增强体与粉末冶金316L不锈钢的反应性

在316L不锈钢粉中分别添加10％的TiC、WC、NbC、Al2O3、Si3N4五种增强体,研究了各种增强体与不锈钢基体的反应性及对烧结过程的影响。结果表明：TiC、WC、NbC与不锈钢基体有良好的相容性,能均匀分布到不锈钢基体中,可以有效提高其强度,添加TiC的不锈钢还表现出优越的耐腐蚀性;由于Al2O3与基体不锈钢相容性过差,不能发挥增强体的作用,使材料的强度和耐蚀性不良;添加Si3N4的不锈钢在烧结过程中Si3N4发生分解,弥散强化了基体,硅有促进烧结的作用,而氮均匀渗透到不锈钢中,有利于形成高强度的高氮钢,从而使其相对密度、硬度及耐蚀性都高于其他材料。     

合金元素含量对耐候钢在模拟海洋大气环境下耐蚀性的影响

采用扫描电子显微镜和电化学交流阻抗谱研究了Q235B、SPA-H钢和2种不同镍、铬及铜含量的耐候钢在模拟海洋大气环境中的耐蚀性。结果表明:在有Cl-存在的环境中,当镍和铜含量都很低时,单独添加铬在腐蚀前期对减缓腐蚀有利,而在后期对腐蚀有促进作用;镍的质量分数小于0.25%时对耐蚀性的影响不起主导作用;电化学交流阻抗试验结果与腐蚀质量损失试验结果一致;4种钢周期浸润腐蚀48h后的锈蚀量都比较少,腐蚀192h后的锈蚀量明显增加。     

新型接地装置技术经济比较

依托虎门滨海大道线路迁改工程的实际情况,从技术性和经济性两方面分别比较了热镀锌扁钢、镀铜钢、纯铜等不同材料接地网,介绍了一些新型接地装置,分析了不同材料的导电性、热稳定性、耐腐蚀性、接地效果等,从降阻、使用寿命和地网稳定性来说明新型产品具有明显的优势,但其缺点为造价稍高。     

高碳马氏体不锈钢440C的热处理工艺

正440C是一种高碳、高铬的马氏体不锈钢,其碳含量(质量分数)达到1%左右,为提高耐蚀性,在Cr13型不锈钢的基础上,将铬含量增加到17%,经过热处理强化可获得很高的强度和硬度,在各类不锈钢中是最高的。由于其高碳、高铬的特性,热处理后碳化物数量多,耐磨性好,同时耐蚀性也较好。440C主要用于一些有高硬度、耐磨和耐蚀性要求的零件,如轴承、轴瓦、喷嘴和阀座等。该钢含碳量高,生产时可能会遇到脱碳、淬裂和残留奥氏体等问题,是较难进行热处理的钢种。本文主要     

耐酸钢1Cr18Ni9Ti的氧氮化

1.耐酸钢表面硬化存在的困难 1Cr18Ni9Ti是一种铬-镍型不锈钢,它有较好的耐蚀性,能抵抗各种酸类的腐蚀,故又称不锈耐酸钢.它有良好的塑性、韧性和焊接性,但硬度较低、耐磨性较差。随着工业生产的发展,对1Cf18Ni9Ti钢在使用上提出了更高的要求,如化工设备、航空工业、石油机械、造船、医疗器械等都要求材料有较高的抗腐蚀性,又要有高的硬度。而1Cr18Ni9Ti钢是一种     

铬锰氮无镍不锈钢尿素设备的制造

我厂在制造尿素设备的过程中,通过试验和生产实践,对铬锰氮无镍不锈钢—A_4钢的性能有了一定的认识,积累了一些制造的经验。生产实践证明,该钢有着良好的综合机械性能和加工工艺性能。耐腐蚀试验和生产试用的结果也证明,该钢在中压、高压系统中具有良好的耐蚀性,可以代替18-12型铬镍钼不锈钢,     

金属纤维在机械工程中的应用

现代机械的发展对机械工程材料各种性能的要求越来越高,某些特殊场合的要求堪称苛刻。因此,近年来各种新材料、新工艺及复合材料层出不穷。金属纤维就是70年代后期出现的一种新型工业材料。 金属纤维有许多种,按材质分,有铜、普通钢、不锈钢、铸铁、铝和其他合金纤     

两种汽车用镀锌钢板在海洋大气环境中的腐蚀产物与耐蚀性对比

对在海洋大气环境中暴露2 a后的电镀锌和热镀锌汽车用钢板进行了腐蚀产物分析,并比较了两者的差异。结果表明:两者均产生了致密的腐蚀产物,腐蚀产物的物相组成也基本相同;在镀层厚度相同的情况下,电镀锌和热镀锌钢板具有相近的耐蚀性。     

热镀锌钢板表面硅烷膜的制备工艺与耐蚀性能

采用正交试验结合中性盐雾试验和极化曲线测定等方法,研究了热镀锌钢板表面的硅烷膜在制备过程中的硅烷体积分数、水解溶剂中甲醇体积分数、水解时间、水解温度、溶液pH值、浸涂时间等因素对硅烷膜耐蚀性能的影响,并确定了最佳成膜工艺,讨论了硅烷膜作用机理。结果表明:最佳成膜工艺为硅烷体积分数7%、溶液pH值4、水解溶剂中甲醇体积分数10%、水解温度40℃、水解时间6 h、浸涂时间120 s,采用该工艺制备硅烷膜可明显推迟热镀锌钢板出现白锈的时间;硅烷膜同时也抑制了热镀锌钢板在腐蚀过程中阳极和阴极的反应,显著改善了热镀锌钢板的耐蚀性能。     

Selection of tool materials and surface treatments for improved galling performance in sheet metal forming

Galling is a known failure mechanism in automotive stamping. It results in increased cost of die maintenance and scrap rate of products. In this study, rectangular pan and U-channel stamping experiments are used to (1) investigate the effect of stress states on galling performance in sheet metal forming, (2) select proper tool materials and surface treatments for improved galling properties, and (3) differentiate galling performances of bare and coated steel sheets. The results indicate that problems with galling are of major interest at the regions where sheet materials deform under the action of compressive stress. For the four investigated tool materials, Mo–Cr alloy cast iron shows the best galling performance. A combination of hardening, surface polishing, and Cr coating is suggested as the optimum tool treatment in the forming of bare high-strength steel. Hot-dip galvanized steel shows better galling behaviors than galvannealed and bare steel sheets. Galling performances of hot-dip galvanized and bare steels are improved with increased hardness of the forming tool. However, galvannealed steel results in severe galling when the hardness of the forming tool is very high.     

纳米氧化镍/锌复合材料的制备及在热浸镀中的应用

用高能球磨法制备了纳米氧化镍/锌复合粉末,然后通过真空热压法将其制成块体复合材料,并熔化于锌液中,在45钢基片上进行热浸镀;用XRD、TEM、FESEM和EDS等对复合粉末、块体复合材料的组织、结构进行了分析;用腐蚀失重法、冲蚀磨损法研究了镀层的耐腐蚀和耐磨损性能。结果表明:用高能球磨法制备的纳米氧化镍/锌复合粉末中,纳米氧化镍颗粒弥散均匀分布在锌颗粒上;纳米氧化镍颗粒的加入能显著提高镀层的耐磨性能,而对耐腐蚀性能影响不大。     

角钢塔材镀锌层检测及其质量控制系统研究

针对角钢塔材镀锌层检测效率低且抽检数据尚无科学的管理信息系统问题,基于工程要求及节距法与米字型测点布置原理进行了角钢塔材镀锌层检测,并运用统计过程控制对角钢塔材镀锌层厚度及均匀性进行分析,开发了角钢塔材镀锌层检测及质量控制系统,提高了检测效率及精度,实现了电网建设物资采购的信息化管理。     

A study on the constitutive model of irradiated austenitic stainless steel for the functionality analysis of nuclear internals

The internal components of nuclear reactor are exposed to the neutron irradiation environment. The constituent materials of the components are susceptible to remarkable changes in the mechanical properties such as elastic modulus, strength, ductility and toughness. The mechanical and thermal deformations are accompanied with the void swelling and the irradiation creep in the environment. The functionality analysis which evaluates the structural integrity of the aged internals needs to take the degradation characteristics of the material into account. In this paper, a constitutive model of austenitic stainless steel developed by EPRI is studied and implemented into numerical analysis vehicles. The mechanical properties of irradiated 304 stainless steel are presented and the deformation behaviors are simulated. The criteria and methodology for the functionality analysis are also discussed and illustrated.     

Humidity Effects on Friction and Wear Between Dissimilar Metals

The effect of water vapor on the friction and wear between copper and 440C stainless steel was studied using a ball-on-flat tribometer, polarization-modulation reflection?Cabsorption infrared spectroscopy, and Auger electron spectroscopy. The wear behavior changed drastically as the relative humidity (RH) varied in inert gas (nitrogen or argon). In a dry environment, a small degree of abrasive wear of soft copper was observed. In the RH range of 10?C70?%, catastrophic adhesive wear of the soft copper surface was dominant. A high RH (>80?%) environment exhibited wear of the hard 440C stainless steel surface and the steel wear debris was deposited onto the copper. The adsorption isotherm measurements for copper and stainless steel revealed that water adsorption increases quickly between zero and 10?% RH and then the adsorption proceeds more slowly as RH increases further. The adsorbed water layer thickness increases rapidly again as saturation is approached. It seems that the thin layer of adsorbed water under 70?% RH facilitates the adhesive wear through passivation of grain boundaries or acceleration of crack propagations, but the thick water layer formed over 80?% RH acts as an electrolyte medium allowing galvanic corrosion to commence.     

A FEM study on the mechanical responses of pseudoelastic TiNi alloys to a particle normal loads

In this study, the models of four materials including three sorts of pseudoelastic TiNi alloys and a stainless steel (as a contradistinction) enduring a particle's normal loads were individually simulated based on bilinear strain hardening law by means of finite element method. Owing to the pseudoelasticity, TiNi alloys proved to have high elastic strain limit and low pseudo-Yong's modulus, with which the special mechanical response was created under normal loads. The results shown that pseudoelastic TiNi alloys occurred plastic deformation more difficult than the stainless steel, and the critical load of plastic deformation increased with the increasing elastic strain limit and the decreasing pseudo-Young's modulus. Plastic regions of three TiNi alloys with the elastic strain limit 0.02, 0.04 and 0.06 were 0.60, 0.32, 0.047 times of that of the stainless steel, respectively. When the pseudoelastic TiNi alloys endured a particle's normal loads, the phenomena of decreasing contact stress, von Mises stress and increasing the elastic strain were also observed in this FEM study. In terms of above results, the wear mechanism of pseudoelastic TiNi alloys was discussed finally.     

两种受电靴材料与不锈钢带电接触摩擦磨损特性的试验研究

在销-盘式摩擦磨损试验机上分别进行了不锈钢／铜基烧结合金材料和不锈钢／铜石墨烧结材料接触的载流摩擦磨损行为的试验研究。在试验中记录了摩擦因数和磨损量的变化，并对磨痕形貌进行了光学显微镜观察。结果显示，电流对2种摩擦副带电接触的摩擦磨损行为有重要的影响。2种材料的摩擦因数随电流的增大而呈现截然相反的变化趋势，但两者的磨损量却随电流的增加而增大。不锈钢／铜基烧结合金材料的磨损机制主要是粘着磨损及氧化磨损。不锈钢／铜石墨烧结材料磨损机制包括磨粒、粘着磨损和电弧烧蚀，其中电弧烧蚀对磨损量的影响随电流的增大而增加。