世界5米级特宽厚板轧机态势浅析

一、概述5米级特宽厚板轧机是指轧机工作辊身长5米以上的厚板轧机,目前能轧制最宽厚板轧机辊身长为5500mm,已建成投产的有4台(日本新日铁大分厂,JEF京滨厂,JEF仓敷厂,德国迪林根公司);厚板轧机轧辊辊身长为5200-5300mm的有5台(美国卢肯斯·     

包钢薄板厂宽厚板精轧机辊缝控制

文章主要从德国轧SMSD引进的宽厚板轧机机械-液压辊缝控制系统出发,分析了宽厚板轧机的机械-液压辊缝控制系统工作原理,其中重点分析了液压辊缝控制系统HGC。     

4100mm宽厚板轧机支承辊辊型曲线优化仿真分析

 辊间接触压力分布是影响宽厚板板形质量和轧辊使用寿命的重要因素,为了获得均匀的辊间压力分布,以4100mm宽厚板四辊轧机为对象,考虑轧件弹塑性变形和辊系弹性变形耦合作用,采用弹塑性热-力耦合非线性有限元方法,数值模拟分析了宽厚板轧制过程的辊间接触压力分布规律,并通过仿真分析,对支承辊辊型及其边部卸载曲线进行了选型和优化改进,获得了以二次曲线为辊凸度和抛物线为辊肩部卸载曲线的辊形,延长了轧辊的使用寿命,改善了宽厚板的板型质量。     

关于四辊轧机工作辊稳定性问题的初步探讨

关于四辊轧机工作辊稳定性问题的初步探讨林揆一（鞍钢厚板厂）鞍钢厚板厂设备是１９９０年从日本引进的二手设备，轧机为四辊可逆复合式４３００厚板轧机。传动形式为传动工作辊式。由于四辊轧机工作辊与轴承之间、工作辊轴承箱与支承辊轴承箱间以及支承辊轴承箱与牌坊间...     

浅谈四辊钢板轧机的技术改造

介绍了济钢宽厚板厂四辊轧机经过技术改造,提高了轧机的装备水平和轧制精度。     

宽厚板轧机机架辊安装方式的探讨

介绍了宽厚板轧机机架辊的安装以及机架辊轴承座的两种夹紧方式，同时提出机架辊维护检修的建议。     

宽厚板轧机机架辊安装方式的探讨

本文介绍了宽厚板轧机机架辊的安装以及机架辊轴承座的两种夹紧方式,提出机架辊维护检修的建议。     

浦项制铁订购5.5米宽厚板轧机工作辊

2010年2月，韩国浦项制铁公司资材／设备采购担当常务朴明吉先生亲自将一份5．5米宽厚板轧机工作辊采购合同交付中钢邢机。这是中钢邢机生产的5米以上宽厚板工作辊首次走出国门。     

新型厚板轧机

英国钢铁公司台齐尔钢厂制造的大型厚板轧机已经投入生产。这台轧机是四辊式1830毫米和1000毫米×4340毫米的厚板轧机。自动化厚度控制新轧机能缩小钢板的厚度公差标准和改进表面光洁度。轧钢机架具有一种改进的自动化厚度控制,新型预应力机架,良好的工作辊和支撑辊的挠度,改进的压下装置能精确地保持压下平衡,全部操作由联机计算机进行控制。这台轧机能将厚610毫米、宽1.8米、重30吨以上的扁坯轧成宽4米、厚5～40毫米的厚板材。     

沙钢5000mm轧机工作辊热网纹形成原因分析与预防措施

热轧板带四辊轧机铸造工作辊辊面经常出现表面热网纹,对沙钢5 000 mm宽厚板轧机工作辊常见网纹的种类、产生原因进行分析,阐述了常用的预防方法和处理处理措施。     

Optimum Design of Welded Steel Plate Girder Bridges Using a Genetic Algorithm with Elitism

The genetic algorithm (GA) is a general optimization technique that has some unique features that are especially suitable for structural engineering problems. This work uses a simple GA with elitism to find the optimum design of welded steel plate girder bridges. The objectives are to minimize the weight and the cost of the girders. Two types of plate-girder bridges are studied: a single-span bridge and a two-equal-span continuous bridge. Bridges with various span lengths, in increments of 20?ft, are investigated; results are tabulated, parametric studies are made, and meaningful conclusions are drawn.     

赣南钨矿山资源状况调查与思考

通过赣南钨矿山资源调查,反映钨矿山资源状况不容乐观。据地质报告中统计,赣南累计探明WO3储量149.98万t,其中上平衡表113.67万t,而保有储量仅有46.7万t;国有钨矿山保有储量26.4万t,可利用的储量10.4万t,可服务年限大都在10a以下。因此,建议尽快对赣南的国有钨矿山开展新一轮的地质找矿,寻找新的接替基地,控制钨矿产量,对尾砂综合回收和利用。     

Energy-Efficient Trajectories of Unmanned Aerial Vehicles Flying through Thermals

This study presents optimal energy-efficient flight trajectories of a generic unmanned aerial vehicle (UAV) flying through a vertical moving thermal cell. A two-dimensional point-mass model of a jet-engined UAV in the vertical plane is used. UAV equations of motion and the thermal wind expression are normalized for numerical efficiency and four fundamental parameters are identified. UAV flights through a thermal cell are formulated as nonlinear optimal control problems that minimize the average thrust per unit time, subject to UAV performance constraints and periodic flight boundary conditions. These problems are converted into parameter optimizations and solved numerically. Fuel efficiencies of these optimal trajectories are compared with those of reference optimal flights in the lack of thermal winds. Both constant thrust and variable thrust solutions are obtained. Two patterns of optimal flights through thermals are identified, and their characteristics are analyzed. Both patterns of optimal flights are also explained from an energy maximization point of view. Effects of the fundamental parameters on optimal UAV flights are examined. Results suggest that significant improvements in UAV fuel consumption are possible by taking advantage of thermal energies.     

客运专线用100米钢轨矫直断裂原因分析

 客运专线用100米60kg/m重轨在焊轨厂拼焊后,当四面矫直时发生断裂。采用光学显微镜及扫描电镜（TEM）等方法对钢轨矫直时断裂原因进行了分析和研究。结果表明：钢轨断裂是由于距钢轨端部约100mm轨底边缘处存在凸台缺陷,此凸台在钢轨拼焊后进行除瘤时除瘤刀将其铲平,致使钢轨产生冷裂纹,进而在矫直时断裂。通过控制万能精轧上下辊的辊径差以及调整轧制线高度等方面,使钢轨出轧机时尽量保持平直,避免上翘或扣头,从而消除凸台缺陷的产生。     

推钢式加热炉的技术改造及效果

介绍了包钢特钢分公司推钢式加热炉技术改造的情况,对加热炉存在的问题进行了分析,提出了改进措施,经过技术改造提高加热炉的能力,降低了煤气消耗,取得了较好的经济效益。     

Stability and Accuracy of Weighted Four-Point Implicit Finite Difference Schemes for Open Channel Flow

The unsteady motion of streams, with a free surface, has been described by a system of equations that were proposed by Saint-Venant in 1871. These are universally known as “Saint-Venant’s equations.” Weighted four-point implicit finite difference schemes are largely used for their numerical solution in the case of one-dimensional flow. For these models, stability, dissipation, and dispersion are first investigated by looking at the truncation error and then by using Fourier’s classic linear analysis. Variations of the space and time weighting coefficients, the Courant number, the Froude number, and the frictional resistance term are examined in this paper. In particular, instabilities are analyzed that are due to the progressive accumulation of dispersion errors, which are the consequence of an increasing frictional resistance term. However, in this case the numerical scheme requires a dissipation mechanism. Computational suggestions are given for this mechanism.     

曼型气柜支柱的安装方法

通过对曼型气柜关键部位之一的基柱的安装和找正过程的分析，表明基柱安装前对基础进行预处理、安装时测量跟踪找正、安装后定位加固，是保证基柱安装精度的三个重要步骤。     

矿产资源定价方法的实证研究

文中分析了资源－环境－经济一体化核算的研究现状及存在的问题,界定了矿产资源核算的内涵及其对象,论述了矿产资源定价的理论基础,探讨了矿产资源的各种定价方法及其优缺点,适用范围,建立相应的估价模型,并进行了实证分析,这项研究对我国的资源－－环境－经济一体化核算的理论研究与实践进展具有重要的理论意义和现实意义。     

钨纳米线的制备与应用

综述了钨纳米线的最新研究进展,详细地介绍了数种钨纳米线的制备技术和这种新型纳米材料潜在的巨大应用价值,提出了目前报道的制备方法中存在的几个问题,并展望了未来的发展趋势。     

k–ε Turbulence Modeling of Density Currents Developing Two Dimensionally on a Slope

Dense underflows developing two dimensionally on a slope are simulated numerically. The k–ε model is used for the turbulence closure. The boundary-layer approximation renders the governing equations in the form of parabolic partial differential equations, which are easier to solve numerically than elliptic equations. Evolution of vertical structures of dense underflows is computed along the streamwise direction. Excellent similarity collapses of the computed vertical structures are obtained. The computed profiles of velocity and concentration are compared with measured data, resulting in good agreement. The impact of a parameter representing the stratification level in the k–ε model is investigated. Appropriate values of this parameter, yielding results that are nearly identical to the integral model, are proposed. Water entrainment coefficients are estimated from computed solutions, and are observed to fall within the range of previous measurements. Finally, by using the collapsed vertical structures, profile constants defined in the integral model are calculated, which assures that the top-hat assumption necessary for deriving the integral model is valid.