工艺参数对振动攻丝扭矩的影响

结合试验结果，分析了在结构钢和合金钢的振动攻丝过程中，基本工艺参数对攻丝扭矩的影响，得出了不同参数对扭矩的影响规律，对于优化工艺参数、减小攻丝扭矩、改善攻丝效果具有一定的借鉴意义。     

Predictive Cutting Models for the Forces and Torque in Machine Tapping with Straight Flute Taps

In this paper the development of predictive cutting models for the forces and torque in machine tapping operations with straight flute taps is outlined. The models, based on the ‘Unified-Generalised Mechanics of Cutting Approach’, allow for the many tap and cut geometrical variables, the cutting speed and the toolcoating-workpiece material combinations. The models have been verified by extensive computer simulation studies as well as comprehensive experimental testing programmes. This investigation has provided a deeper understanding of the basic cutting action as well as predictive force models of tapping, renowned as “one of the most neglected operation in machining research”.     

On the Self-Affine Fractal Geometry of Plasma-Sprayed Surfaces

Surface roughness strongly controls essential properties of thermally sprayed wear- and corrosion-resistant coatings including their mechanical adhesion to the substrate, tribological performance, efficient retention of lubricating materials, and also the presence of sufficient carrying surface able to support the wear couple along the line of contact expressed by the Abbott-Firestone curve. The determination of the surface fractal geometry may yield useful information on the topography of plasma-sprayed coatings beyond that provided by a single roughness parameter such as R _a or R _z. The fractal geometry of atmospheric plasma-sprayed chromium oxide coatings, deposited according to two different statistical experimental design protocols, was assessed through determination of the Hurst exponent H of fractal Brownian motion (fBM), as well as the area-scaled fractal complexity (ASFC) obtained by triangular tessellation (“patchwork” method). Attempts were made to correlate fractality with coating adhesion strength.     

滑板挡渣技术应用与探讨

文章介绍了转炉滑板挡渣设备的原理及在安钢第二炼轧厂150 t转炉的应用效果,并对转炉挡渣设备的使用优化进行了探讨。转炉滑板挡渣设备投入使用后,针对使用过程中出现的问题,第二炼轧厂组织技术人员,仔细分析问题产生的原因,对部分突出问题技术攻关,找出相应的解决方案,并先后对3座转炉滑板挡渣设备的液压系统、冷却系统、操作系统进行了优化改造。结果表明,滑板挡渣技术运行可靠,可大幅降低炼钢成本消耗,值得在国内外推广和应用。     

Factors Affecting Temperature Drop between Tapping and Teeming

Quantitative relationships among the factors which affect temperature variations between furnace tapping and teeming are analyzed, and a procedure is developed for determining the probable temperature change.     

消除水咀铸件的缩松缺陷

０前言我厂生产的各种规格的闸阀、水咀等铸件材质为可锻铸铁，其中水暖件的水咀牌号为ＫＴＨ３３０—０８。该零件形状较为复杂，技术要求不允许有渗漏现象，而我厂在１９９９年年初生产的水咀铸件，因渗漏导致大量废品，为此，进行了攻关改进。１工艺分析及改进措施水咀的结构形状如图１。采用手工脱箱造型，一箱八件。铸件的技术要求，必须经过水、气压力测试，不允许有渗漏现象。在１９９９年年初，批量生产的水咀铸件，经试压检验，发现渗漏严重，占批量的３０％。为此，通过废品分析制订了工艺改进措施：１１对渗漏的水咀铸件进行解剖…     

变压器分接开关的电气改造

本文从分析变压器原先的机械式分接开关在实际使用过程中存在的主要问题出发。主要介绍了机械式分接开关如何改造成电气控制及相应的电气线路图的改进和设计。     

接柄丝锥真空热处理技术研究

研究了经真空加热淬火和盐浴加热淬火的W6Mo5Cr4V2钢制接柄机用丝锥的组织和性能。发现,淬火温度相同,经这两种工艺淬火处理的丝锥的晶粒度、碳化物溶解程度非常接近,但回火后,经真空加热淬火的丝锥碳化物颗粒更为细小均匀,根据国家标准进行了切削试验,其切削性能达到了一等品的水平。     

Tapping the Memory in Archaeological Metals

Over the last twenty years, there has been a discernable increase in the number of scholars who have focused their research on metal production, working and use in antiquity, a field of study which has come to be known as archaeometallurgy. Materials scientists and. conservators have worked primarily in the laboratory while archaeologists have conducted fieldwork geared to the study of metal technology in a cultural context with laboratory analysis as one portion of the interpretive program.     

基于小波分析的汽车EPS扭矩传感器故障检测

针对扭矩传感器正常工作信号、发生故障时信号和噪声信号在小波变换下的不同传播形式,利用小波变换的多分辨率分析特性,提出一种EPS扭矩传感器信号消噪和故障检测的方法,建立各种信号的模型,并进行仿真分析.结果表明,该方法能有效抑制噪声信号并检测出故障发生的时刻和故障信息,对汽车EPS系统的安全运行及故障诊断具有重要的工程应用意义.     

丝锥柄部淬火开裂分析及防止措施

机用M10丝锥采用两种材料对焊而成，其柄部材料为45钢，刃部材料为W6M05Cr4V2钢。柄部技术要求为：硬度(35～45)HRC，并在1／2～2／3柄长范围内保持(35～45)HRC。当柄部采用850℃盐浴加热，在8％CaCl2(质量分数)的水溶液冷却的常规工艺淬火时，柄部方尾处产生淬火裂纹(见图1所示)，批次裂纹发生率平均为27％，严重影响了正常生产。为此，对丝锥柄部淬火时出现的淬火裂纹予以分析，从而提出防止淬火裂纹产生的工艺措施，以解决生产难题。     

冲天炉连续出铁出渣装置及其使用

介绍了三种常见的长炉龄冲天炉连续出铁出渣装置的特性,适用范围以及使用要点.     

复合振动挤压攻丝机的设计

介绍了复合振动挤压攻丝机的工作原理和主要特性,在此基础上,阐述其控制系统的组成结构.新型振动攻丝机采用数控技术,实现了攻丝靠模通用化,具有周向和轴向振动功能,满足振动挤压攻丝新工艺的要求.     

水龙头注射模设计

分析了水龙头的塑件工艺特点，介绍了水龙头注射成型模结构及模具的工作过程。此水龙头注射模设计的结构特点是侧浇口形式的单分型面的注射模，具有侧向抽芯。经过生产验证，该模具结构设计巧妙，操作方便，使用寿命长，用该模具生产的塑件达到技术要求。     

异形薄壁铜管水嘴的管端封口

阐述了一款T2薄壁紫铜水嘴结构特点,分析管端封口工艺,提出其管端封口工艺的技术创新方法并加以实现,满足客户要求.     

防止出铁口"冻结"的实践

初步分析了第一次出铁时出铁口“冻结”的原因，通过生产实践总结出了几条防止出铁口“冻结”的措施。     

Geometry of polyaniline

In order to get a quantitative picture of the geometry of polyaniline, we have carried out MNDO calculations on segments of the polymer. The completely oxidized form (2A) shows an alternating benzoid-quinoid structure of the six-membered carbon rings, while the completely reduced form (1A) is all benzoid. The torsion angles between adjacent rings in the 2A and 1A forms are calculated to be 87° and 82°, respectively. In the protonated 2S′form the torsion angle between rings adjacent to a protonated nitrogen is reduced to ∼72°, while the torsion angle between rings adjacent to an unprotonated nitrogen is still close to 90°. The benzoid-quinoid structure is preserved in the 2S′ form and the charge transferred to the polymer chain is found to be well delocalized. We also present data from n.m.r. experiments on oxidized polyaniline before and after protonation. These data can be interpreted in a way consistent with the geometry obtained from the MNDO calculations. The n.m.r. spectrum of oxidized and protonated polyaniline is rather featureless, but the similarity in the distributions of chemical shifts between the spectra implies that the structure is unchanged upon protonation and that the injected charge is delocalized, i.e., in agreement with the MNDO results.     

安装热分管和进行套管补焊的简易方法

在运行管道上施焊时，为了避免管道流量和内存物流失，可以安装分支连接设备（热分管）和备用套管以节约成本。在施工时，有两点需要考虑：第一，焊工的安全性。由于电弧可能焊穿管道壁，引发内存物的喷溅，给焊工形成安全隐患；第二，管道焊后焊缝的完整性。