焊接质量的在线控制与预测研究现状及发展趋势

由于影响焊接质量的因素很多，焊接产品的质量难以保证，开展焊接质量的在线控制与预测具有极其重要的意义，为促进国内焊接质量的在线控制与预测研究工作，介绍了国内外焊接质量的在线控制与预测方面的研究进展，同时分析了未来焊接质量的在线控制与预测研究的发展趋势。     

略谈当前高校教育质量保障的"三动三不动"

本文提出,当前高等教育改革存在“外动内不动”,“上动下不动”,“心动行不动”的“三动三不动”现象,它是当前影响我国高等教育质量保障的主要问题。本文从实践和理论两个层面对其原因进行了分析,并对解决这一问题的思路进行了讨论。     

提高5005合金铸轧产品质量的有效途径

熔体质量和工艺裂边是影响5005合金铸轧产品质量的重要因素之一。分析了5005合金熔体气、渣来源,阐明了熔体精炼机制,通过工艺优化,使熔体中氢含量降至0.12 mL/(100 g Al);同时,通过调整铸轧区长度、改进铸嘴耳子结构,使5005合金铸轧带材的裂边减至7.5 mm左右。铸轧带材的产品质量明显提高。     

Worker Exposure Monitoring of Suspended Particles in a Thermal Spray Industry

The purpose of the present work was the investigation and characterization of the quality of air in a thermal spray industry, in Greece. The activities that take place in the specific facility, as well as in most other similar industries, include thermal spraying and several mechanical and metallurgical tasks that generate airborne particles, such as grit-blasting, cutting and grinding of metallic components. Since the main focus of this work was the workers exposure to airborne particles and heavy metals, portable air samplers with quartz fiber filters, were used daily for 8 h. Three samplers, carried from different employees, were used for a period of 1 month. Results showed that both particles and heavy metals concentrations were low, even in the production site, which was the most susceptible area. The only exceptions were observed in the case of cleaning and maintenance activities in the thermal spray booth and in the case of spraying outside the booth. The main reason for the low concentrations is the fact that most of the activities that could produce high-particle concentrations are conducted in closed, well-ventilated systems. Statistical elaboration of results showed that particles are correlated with Ni, Cu, Co. The same conclusion is extracted for Fe, Mn. These correlations indicate possible common sources.     

咨询设计单位的质量管理

指出作为咨询设计单位 ,除了要做好设计前期工作、初步设计、施工图设计之外 ,还应做好施工现场的服务工作。笔者根据多年从事工程咨询设计和质量管理工作的经验 ,提出了咨询设计单位对工程咨询设计质量管理的基本要求 ,可供同行们借鉴、参考。     

Spin Extrusion - A New Partial Forming Technology based on 7 NC-Axes Machining

Hollow shape component approaches, applied to shafts and similar workpieces, represent a major potential for ground-breaking innovations in lightweight engineering and safety designs. Among suitable forming technologies, spin extrusion is a pioneering and particularly flexible hollow-shaping technique. All outside form elements, straight or stepped cylinders, cones or spherical rotation elements emerge just from the kinematics of tools. The inside hollow shapes, as e.g. circular cross-sections, shaft to collar connections such as spherical triangles, polygons, splines or dovetail forms are manufactured with a shaping mandrel. Spin extrusion can be applied first and foremost at dimensions that are unattainable with other techniques. The application includes hollow shafts, thick-walled cups and semi-finished tubular products that are not to be found in off-the-shelf cross-sections. In these cases the possibility for using of massive bars is connected with very high price advantages. Furthermore material-saving machining is attracting special attention for high-grade materials.The paper characterizes substantial steps of process analysis and the appliance of a new, derived from the bound method, numerical simulation method for spin extrusion process. Holistic process analysis is the prime factor for process capability. The specific application of the developed special methods of simulation, the accumulation of process data and the integrating into the Computer numerical control of spin extrusion machine is a precondition guaranteeing high-quality assurance.     

呋喃树脂自硬砂在纺织机械铸铁件上的应用

介绍呋喃树脂自硬砂在纺织机械类铸铁件生产中的实际应用，详细阐述了原材料选取，呋喃树脂自硬砂制备工艺、造型与制芯等工序的操作要点及应用实例，分析了呋喃树脂自硬砂代替普通粘土干型砂工艺的利益所在。     

等离子电弧力的研究

从等离子电弧力的角度 ,探讨了等离子弧焊接工艺参数及其匹配的内在联系与规律性。在不同工艺条件下 (焊接电流、等离子气流量、电极内缩量以及喷嘴高度 )对等离子电弧轴向力进行了测量。并通过显著性分析 ,定量地认识和描述了各工艺参数对电弧轴向力的作用和影响。进而指出了获得稳定的小孔型等离子弧焊接过程的必要条件。本文的工作对于等离子弧焊接工艺参数的匹配及其过程的优化有重要的指导意义。     

Incoloy 800H/20g复合板材料焊接技术探讨

研究Incoloy 800H／20g复合板焊接工艺，以解决以镍基合金复合板材为主体的设备在焊接过程中易产生裂纹、气孔及成分偏析等问题。焊接实验选择H1Cr16Ni21作为过渡填充金属，采用惰性气体保护焊和手丁电弧焊2种形式焊接。实验结果表明，选择H1Cr16Ni21作为过渡填充金属，采用小电流、多道次焊接工艺，可得到质量良好的焊缝，焊缝宽度、焊缝余高、咬边及焊接错边均符合JB4730-94标准要求；力学性能优于20g耐热钢。焊缝成分与Incoloy800H接近。成功地解决了成分差异较大的2种材料焊接时易出现裂纹和气孔的问题。     

我国钢筋质量与国际先进水平的差距

回顾了我国近50年来带肋钢筋的生产状况，综述了国际上一些发达国家对普通钢筋不断提升质量水平的发展趋势及对钢筋标准的修订；并就我国在生产普通钢筋和修订标准、规范中应关注的若干问题提出了建议。