镍及镍合金的应用及展望

文章介绍了镍及镍合金的材料学基础知识、典型用途、市场需求,以及国内镍产业的发展状况,着重介绍了目前陕西省代表性企业宝钛集团有限公司的镍及镍合金产业状况和规划,含生产设备、技术工艺研究、相关成果,客观分析了存在的不足,并对将来镍及镍合金的发展进行了展望.     

钼及钼合金烧结技术研究及发展

从粉末冶金烧结理论、烧结设备、烧结工艺参数及新型烧结技术等方面概述了钼及钼合金烧结技术的研究现状及进展。结论指出, 钼及钼合金烧结理论仍集中在传统粉末冶金理论体系; 烧结技术发展方向是获得全致密化、细晶、均质化的烧结坯体; 发展趋势是烧结设备及工装与粉末冶金新技术结合更为紧密, 出现更多交叉研究; 研究热点和难点是大型钼及钼合金坯件烧结致密化、微观组织均质化、细晶化及复杂烧结态异型坯件烧结过程中形状精确控制等。     

冷轧轧机乳化液净化及油泥处理系统设计及应用

针对冷轧轧机乳化液净化及油泥处理系统设计及关键技术进行研究,设计了一种高效导流式磁过滤装置及铁含量在线监测及磁过滤器过滤闭环控制系统.针对含铁量较高的过滤物油泥使用了环保高效过滤物高温碳化处理技术,从而达到对冷轧轧机乳化液的高效、智能、环保净化.     

宽厚板及中板产品发展趋势及市场定位研究

本文通过宽厚板及中板轧机建设、下游行业的发展及宽厚板及中板生产和市场需求等蒯研分析,预测了宽厚板及中板产品的发展趋势,进而对产品的市场定位进行了分析研究。     

铜及铜合金粉末应用及研究现状

本文介绍了近几年国内外铜及铜合金粉末应用及研究现状,并分析了我国同国外先进水平的差距,以及国内目前行业在生产技术、装备和市场等方面存在的问题,为今后行业发展提出了建议.     

铜及铜合金带材表面质量控制及技术现状

综述了目前国内高精度铜及铜合金带材表面的质量状况,提出表面物理缺陷和化学缺陷及其概念,描述了带材表面各种缺陷的形貌特征,分析了缺陷产生的原因及关键工序的控制要点;介绍了目前铜带表面质量控制采用的新技术、新材料及表面缺陷量化等技术的应用现状.分析表明,高精度铜带表面质量中起皮、划伤、擦伤和凹坑等表面物理缺陷是产品质量投诉的主要原因,而影响铜带表面质量的因素众多并贯穿于生产的整个过程.加强技术创新和新技术、新材料的应用,提高各工序的产品质量保障能力,同时精细管理、细心操作、采用缺陷量化检测手段是控制表面质量及提升产品品质的关键.     

桑椹化学成分及药理作用研究进展

通过查阅近10年的文献资料,对桑椹的营养、功效成分及药理作用进行了综述,以期为桑椹资源的深入开发及更好利用提供参考.桑椹营养丰富,其营养成分主要有维生素、矿物质、蛋白质、脂肪酸及多糖等.桑椹具有增强免疫力、抗氧化、预防心脑血管疾病及抗癌等功效,与其功效相关的成分主要有花色苷、非色素酚类物质、多糖和白藜芦醇等.作为功能食品开发原料,桑椹必将具有更加广阔的应用前景.     

钛及钛合金板材冲压成形及有限元模拟

综述了钛及钛合金薄板的塑性及冲压成形性,在此基础上研究了钛板冲压成形的影响因素,着重分析了压边力、模具尺寸对钛板冲压成形的影响。然后介绍了有限元模拟的基本原理及壳单元、本构方程的选择,并利用DYNAFORM软件模拟了TA2纯钛半球形工件的成形过程,并对压边力进行优化,得出最适压边力范围为27~37 kN。     

高强度不锈钢应用及研究进展

高强度不锈钢因其优异的综合性能及成熟的生产工艺,已成为航空、航天、海洋、石化工程等高端制造业领域的重要材料。系统回溯高强度不锈钢的发展及应用历程,总结此类钢的强韧化机理及最新研究进展,并详细梳理了影响该钢的氢陷阱行为及氢脆抗力的主要因素。结合现有研究成果,提出了采用多种类纳米级第二相颗粒复合析出强化突破高强度不锈钢强韧性匹配极限的思路;通过调控钢中析出相及逆转变奥氏体的交互析出行为,提高后者的机械、化学稳定性,使其作为钢中裂纹及可扩散氢的双重“陷阱”,从而提高钢的裂纹及氢脆抗力。最后指出未来新型高强度不锈钢的研发须重点关注以材料基因算法、人工神经网络、机器学习为代表的“人工智能化”合金设计理念。     

镁及镁合金等通道转角挤压研究进展及发展趋势

镁及镁合金属于HCP结构,织构和晶粒尺寸是影响其性能的主要因素.本文对近年来镁及镁合金等通道转角挤压(Equal channel angular pressing,ECAP)的研究状况进行了综述,介绍了ECAP过程中影响镁及镁合金织构的主要因素.根据晶粒细化机制的不同,从两方面介绍了ECAP工艺制备镁及镁合金超细晶、纳...     

钛渣酸解过程中物相变化特征探讨

明确物相变化是剖析钛渣酸解机理和改进酸解工艺的关键点之一.综合应用化学分析、X射线衍射(XRD)分析、矿物解离分析以及扫描电镜形貌分析对某74钛渣酸解过程中主要物相的含量、形貌变化以及Ti、Si两种元素的含量及赋存变化进行了研究.结果表明:钛渣主要由黑钛石和辉石组成,酸解过程中黑钛石含量逐渐减小,辉石含量逐渐增加;反应...     

C. Shaler Smith

Smith was one of the premier bridge builders of the post-Civil War period. He started his bridge building career under Albert Fink on the Louisville and Nashville Railroad. During the Civil War, he designed and built a powder factory for the Confederacy at Augusta, Ga. After the war, he formed Smith and Latrobe Co. and later The Baltimore Bridge Company with Benjamin and C. H. Latrobe. He worked closely with James Eads on the St. Louis Bridge and designed and built the long iron easterly approach to the bridge. He designed and built some of the major viaducts, swing, and fixed span bridges in the United States, Australia, and Peru, and finally innovative cantilever bridges over the Kentucky, Mississippi, and St. Lawrence Rivers.     

热轧不锈钢板酸洗工艺

为去除热轧不锈钢板表面的氧化层与贫铬层,钝化基体,改善表面质量,在热轧退火后需进行酸洗处理。介绍了热轧不锈钢板表面氧化层和贫铬层的组成与结构特征及其对酸洗过程的影响,并对热轧不锈钢板的酸洗体系设计和酸洗工艺开发进行了阐述。中国热轧不锈钢板普遍采用前处理(机械除鳞、中性盐电解等)→硫酸(电解)预酸洗→硝酸-氢氟酸终酸洗的酸洗工艺,旨在通过前处理和预酸洗去除大部分的氧化层,在终酸洗阶段去除残余氧化层及贫铬层,同时实现基体钝化。目前,热轧不锈钢板的酸洗工艺存在酸洗效果不稳定、贫铬层去除不完全、局部腐蚀较为严重等问题,且会产生不同程度的环境污染问题。应该根据不同钢种不同退火工艺条件下的表面氧化层与贫铬层的性质与分布特征,研究开发相应的酸洗体系和酸洗工艺。热轧不锈钢板的环保型酸洗新工艺具有广阔的发展前景。     

Evaluation, Rehabilitation Planning, and Stay-Cable Replacement Design for the Hale Boggs Bridge in Luling, Louisiana

The Hale Boggs Bridge opened to traffic on October 5, 1983. At the time, it was the first U.S. cable-stayed crossing over the Mississippi River. The PE (polyethylene) protective sheathing was damaged in many of the cables before and during installation, and after the opening of the bridge to traffic. Repairs were attempted to correct the defects in cable sheathing. Many of the repairs performed poorly and failed to protect the main tension element. The condition of 39 out of 72 cables indicated a critical need for repair and timely action was recommended. To address these damages, and to assure the structural integrity of the bridge structure, several strategies involving a range of repair and replacement options were evaluated using life cycle cost analysis. It was concluded that the strategy to replace all cables presents the best value among evaluated alternatives. The design of the complete 72 cable array replacement is the first occasion on which this process is attempted in North America. The final design of the replacement cables is heavily influenced by the geometric restrictions of the existing anchorage locations. The replacement cables are being designed for a 75-year design life and incorporated with the latest advancements in corrosion protection and vibration control. Maintenance of traffic design is an essential part of the project. The bridge is a critical regional link and constitutes a hurricane evacuation route. Traffic maintenance during cable replacement was designed to be as unobtrusive to the public and commerce as practical. This paper describes efforts associated with cable condition assessment, rehabilitation strategy, and design considerations and concepts, undertaken by the writers since 2002 to improve the condition of this major river crossing.     

河钢石钢智能制造的思考

对工业革命的发展特点进行了评述,对3.0和4.0的建设过程进行了描述,强调了信息化建设期间应注意的几个问题。在此基础上分析了河钢石钢公司的现状,对河钢石钢公司的发展阶段进行了定义。讨论了河钢石钢公司发展智能制造的必要性和可行性。在阐述作者对智能制造的理解之后,提出了河钢石钢应借搬迁之良机按发展智能制造的思路规划建设。还就河钢石钢建设智能制造3.0和4.0的若干问题提出了具体建议,指出智能制造建设将是一个长期的、持续的升级过程。     

Design and optimisation of charging ingredients and structure in an ironmaking system (Part II)

In order to maximise the reduction of pig iron cost in an ironmaking process, and at the same time ensure the output and quality of the pig iron, a design and optimisation system for the charging ingredients and structure in an ironmaking system was established using metallurgical theory. The system includes six modules, namely, sinter metallurgical performance testing and analysis, sintering burdening design, sinter component and property prediction, blast furnace burdening design, blast furnace batching calculation and ironmaking system burden optimisation. Based on actual production, testing and material balance theory, the system integrated these modules on VB and MATLAB using a series of intelligent algorithms, such as the BP neural network, multiple objective linear programming, genetic algorithms and so on. As a result, the optimum burden composition and structure of the sinter and blast furnace that satisfied all the constraint conditions could be obtained. Standing as a pinnacle of the global ironmaking production, the system can design and optimise not only the sintering burden, but also the blast furnace burden. Compared with the traditional production testing and hand calculation in the ironmaking system, the project can greatly reduce the production risk and greatly increase the calculation accuracy. Industrial application shows that the system is especially beneficial to reduce the ironmaking cost and at the same time ensure the output and quality.     

长流程钢铁企业检化验设施的现代化设计

检化验系统对钢铁企业的进厂原料检验、中间产品检测、出厂产品质量判定等有着重要意义。对钢铁企业检化验系统的设置原则、组成和发展趋势进行了介绍,集中化、智能化和信息化是现代化钢铁企业检化验系统的特点。重点论述了原料取制样系统、原料分析中心、冶炼分析中心和轧钢检测中心的建设设计理念。随着中国智能制造发展,全自动智能检测系统、信息流过程自动化及实验室管理自动化已成为当今钢铁企业检化验系统设计不可避免的趋势。     

Numerical Modeling of Contaminant Transport through Soils: Case Study

This paper presents the development and validation of a numerical model for simulation of the flow of water and air and contaminant transport through unsaturated soils. The governing differential equations include two mass balance equations for the water phase and air phase together with a balance equation for contaminant transport through the two phases. In the model the nonlinear system of the governing differential equations was solved using a finite-element method in the space domain and a finite difference scheme in the time domain. The governing equation of the miscible contaminant transport including advection, dispersion-diffusion and adsorption effects are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to standard experiments on contaminant transport in unsaturated soils. The application of the model to a case study is then presented and discussed. Finally, the merits and limitations of the model are highlighted.     

2004年铁合金市场回顾与2005年展望

2004年国际和国内铁合金价格波动较大，全年价格总体水平较往年有较大增长。2004年我国铁合金行业产销两旺，全年产量和出口量均创历史新高，市场价格较往年也有明显改善。但是，铁合金行业发展过热已引起国家有关部门和业界的高度重视，并相继出台了一系列相关的产业政策和调控、指导性措施，对整个铁合金行业的发展产生了深远影响。文章从生产、消费及进出口等方面对2004年中国铁合金市场进行了分析并对2005年市场前景进行了预测。     

Design Error Classification, Causation, and Prevention in Construction Engineering

Construction and engineering practitioners have found it increasingly difficult to learn from their mistakes, particularly with regard to the prevention, identification and/or containment of design errors. Yet, design errors have been the root cause of numerous catastrophic accidents that have resulted in the death and injury of workers and members of the public. This paper examines and classifies the nature of error and design error causation in construction and engineering projects. A review of the normative literature revealed that design errors are caused by an array of factors that can work interdependently. A generic framework is developed that classifies design error according to people, the organization, and project is presented. The paper suggests that people, over and above organizational and project management strategies, have the greatest propensity to reduce errors through the process of situated learning and knowing. This is because the working environment provided by an organization and the processes used to deliver construction and engineering projects influence the nature and ability of people to undertake tasks. Consequently, there is no single but rather a multitude of strategies that need to be adopted in congruence to reduce design errors so that safety and project performance are ameliorated.