马氏体钢耐磨性与亚表层硬度分布的关系

选用２０Ｃｒ，４０ＣｒＳｉ，６０Ｍｎ，Ｔ８和Ｔ１０钢，通过热处理获得不同固溶碳量马氏体，研究在静载三体磨粒磨损后，上述五种钢耐磨性与其亚表层硬度分布的关系，结果表明，马氏体钢耐磨性与亚表层硬度分布的关系与共马氏体固溶碳量有关。     

Deformation and cracking behavior of protective oxide scales on heat-resistant steels under tensile strain

The deformation and cracking behavior of oxide scales formed in air on four heat-resistant steels and on nickel 99.6 have been studied in constant-extension-rate tests at 800°C. The strain rates in the experiments ranged between 10^–6 and 10^–9 s^–1. Acoustic emission (AE) was used as an instrument for detecting the beginning of scale cracking. Additionally, metallographic, SEM, and micro-probe investigations were performed which supported the results from the AE measurements. The strain-to-cracking of the scales did not exceed 0.5% except when lateral growth effects in the oxide scales occurred, leading to critical strains of up to nearly 2.5%. Also the crack distribution in the scales was measured. The deformation and cracking behavior of the scales investigated could be explained by model like considerations.     

旧铁路客运站的保护性再利用

论述了我国部分旧铁路客运站的命运,研究了国外及国内旧铁路客运站保护性再利用的途径,对我国旧铁路客运站的保护性再利用进行了探索研究,以使旧铁路客运站获得新生,并成为连接历史与现代的纽带。     

Polyphenyletherketone and polyphenylethersulfone adhesives for metal-to-metal joints

Two major factors play an important part in improving adhesive bonding in crystalline polyphenyletherketone ( ) and amorphous polyphenylethersulfone ( ) polymer-to-metal joint systems: (1) the mechanical strength of reaction product layers formed at polymer/metal interfaces is greater than that of the polymer itself; and (2) the extent of mechanically weak Fe₂O₃ layers on interfacial metal surfaces, which should be minimized to avoid the undesirable cohesive failure mode through these layers. As a result, the most promising failure mechanism for good bond performance was the mixed cohesive failure modes in which separation occurred in both the polymer and adhesive layers at the polymer/metal interfaces.     

多片BCD拨码盘与单片机接口电路

本文主要讲述多片BCD拨码盘在与MCS－51单片机接口时的一种简单而有效的隔离方法及相应的软件设计。     

秦沈铁路客运专线过渡段施工技术

结合秦沈客运专线过渡段设计特点 ,介绍秦沈客运专线过渡段的主要形式及施工工艺要点 ,提出了相应的施工质量控制措施 ,并总结了几点成功的经验。     

The role of alloying elements in commercial alloys for corrosion resistance in oxidizing‐chloridizing atmospheres. Part II: Experimental investigations

In an extensive study the role of the alloying elements in commercial alloys for corrosion resistance was studied in air without and with 0.1 and 2 vol.% Cl₂, respectively. In the first part of this paper [1] the thermodynamic fundamentals were discussed on the basis of the new concept of the quasi‐stability diagrams. The second part which is presented here reports the results from investigations at 650, 800 and 1000°C and testing times up to 1000 hrs where 14 commercial alloys were tested with regard to their corrosion behavior. The materials were selected so that the role of the alloying elements Mo, C, Si, Al, N, Fe, Ni and Cr would be evident from the results. The exposure tests were followed by extensive microstructural analyses of the corrosion scales and the metal subsurface zones so that type, mechanism and extent of corrosion could be characterized in great detail. At the end a ranking was possible of the different materials and with regard to the detrimental or beneficial role of the different alloying elements. The present results thus provide a much deeper insight into materials resistance in oxidizing‐chloridizing environments at high temperatures.     

一炼钢二次除尘风机液力耦合器事故原因分析及处理

宝钢研制的国产化大型液力耦合器中有多台发生事故(或报废),文章通过对一台3 700 kW×1 485 r/min可调速型液力耦合器的修复,分析了液力耦合器发生故障的真正原因.,主要是滑动轴承的装配精度问题;相应作出了有效的处理方法.对同类型液力耦合器的检修有参考作用.     

Application of region growing method to evaluate the surface condition of grinding wheels

Grinding is a time-varying process affected by factors such as wheel construction, dressing parameters, operating parameters, workpiece material and cooling. The influence of these factors on wheel wear can be evaluated by monitoring the wheel condition. Measurement of wear flat area provides information on the condition of the wheel, but unfortunately it can be a tedious, time consuming, and expensive process. In this paper, a new system to measure wear flat area is presented. This system is mounted on the grinding machine and automates the measurement process by using computer control to automatically position the wheel and capture digital images of the wheel between grinding cycles. Image processing software is then used to analyze the digital images and measure the wear flat area. The proposed measurement system was validated using a scanning electron microscope. Experiments were performed on a Brown & Sharpe Micromaster 824 surface grinder to examine the relationship between wear flat area, normal force and depth of cut. The results agree with the literature.     

八头高速蜗杆副的国产化研制

在分析八头高速蜗杆传动使用要求和使用条件的基础上，对蜗轮蜗杆进行重新优化设计．采用Nieman蜗杆齿形，同时采用了一系列特殊加工工艺及提高蜗轮蜗杆的加工精度和啮合精度措施，使新研制的蜗轮蜗杆达到了国产化的目标和生产使用要求，取得了较为满意的结果。