中厚板轧制展宽新公式推导及其应用

分析了中厚板的轧制过程,建立了变形方程,推导了中厚板轧制展宽新公式。该公式反映了中厚板各轧制阶段间钢板尺寸的关系,其计算精确,有利于轧制过程控制、钢坯安排、压下规程设定,以及板形和平面形状控制。同时,介绍了该公式的使用方法。     

中厚板轧制规程优化设计系统的开发及应用

本文根据中厚板轧制规程设计的要求,用Visual BASIC开发出中厚板轧制规程优化设计系统.系统可按设备能力、产品产量、板形和平面形状等质量要求进行轧制规程设计.系统应用于生产实际取得良好效果.     

轧制工艺对X70钢级管线钢钢板板形的影响

为改善X70钢级管线钢的轧制板形,在不采用弯辊力和辊型控制的情况下,研究轧制工艺对轧制板形的影响,在轧制道次压下率、轧制力和轧制速率等方面进行优化,从而获得良好终轧板形。分析认为:精轧道次轧制力均匀分配时,钢板强度较低,低温冲击韧性较差,精轧时易出现浪板;合理分配精轧末3～4道次轧制压下率,有利于减少分配的轧制力和凸度波动,获得良好的板形;适当降低轧制速率,可降低变形抗力,使钢板的变形更均匀,也有利于减少浪板。     

基于轧制规程优化的带钢热连轧产品可轧范围研究

以轧制温度、轧制力、轧制力矩、电机功率为约束条件,建立了热连轧最小可轧厚度的约束模型;以板形良好为限制条件,以相对等负荷为优化目标建立了轧制规程优化模型。经计算对比发现,采用该模型优化后的轧制规程,不仅可以保证板形良好,而且相对等负荷分配可以充分发挥轧机和电机的能力,从而更精确地计算出最小可轧厚度。在此基础上,针对不同产品厚度和宽度规格,开发了可轧范围模拟计算程序。通过计算对比,该程序具有较高的计算精度,能够准确反映出不同钢种的可轧范围规律。对于某一轧线:当产品较宽时,最小可轧厚度主要受限于轧制力、轧制力矩等约束条件;当轧件较窄时,轧机力能参数富余量大,最小可轧厚度主要受限于终轧温度。     

宝钢2030mm冷连轧机轧制规程及其优化

宝钢2030mm 冷连轧机是国内第1台由西德引进的全连续轧机,其轧制规程有一定特点。在进行道次计算时,轧制规范是进行压下负荷分配的重要依据。轧制规范选择得好,不仅可获得较好的符合工艺条件的轧制参数,使轧机连续、稳定、顺利地轧出符合质量要求的各种规格的带钢,而且能使设备处于最佳状态。     

智能算法优化轧制规程的优缺点及发展趋势

现代轧制对轧制规程的要求越来越高,不仅体现在板形的质量上而且还体现在能源的消耗和环境的保护上。因此,合理的轧制规程就显得至关重要。制定合理的轧制规程要考虑的因素很多,其中最重要的就是轧制过程中的负荷分配。本文以优化轧制规程为目标,着重介绍了几种常用智能算法以及优化轧制规程的优缺点。阐述了智能算法的改进和智能算法对轧制规程寻优的新趋势。     

单机架可逆冷轧机轧制规程优化设计

以唐钢冷轧薄板厂1 800 mm单机架可逆冷轧机的2级轧制规程为研究对象,在分析轧制负荷分配对冷轧带钢板形精度影响的基础上,系统研究了冷轧轧制模型,应用最优化方法编制了轧制规程设计程序并付诸工程实践。     

不可逆轧机冷轧铝板带厚度分配方法研究

提出不可逆轧机冷轧铝板带一种厚度分配方法,即首先确定总轧制道次数,然后给出各道次的压下率上下限,最后求解插补因子(?),从而获得各道次的厚度分配值,并可通过压下区间调整因子μ来改变各道次的压下区间。通过计算实例和分析证明,这种方法简单灵活,获得的厚度分配结果合理有效,具有很高的实用价值。     

超薄规格热轧板卷稳定轧制及板形控制技术

唐钢UTSP生产线通过对板坯温度控制、压下分配、轧制速度、板形控制等进行研究和实践,开发了薄板坯连铸连轧生产线辊底式加热炉蓄热式燃烧技术与超薄规格板卷稳定轧制技术,提升了板形控制能力,提高了超薄规格板卷轧制稳定性和板形质量,实现了薄板坯连铸连轧生产线1.0 mm超薄规格热轧板卷的大批量稳定生产。通过技术升级和改造,目前1.0 mm超薄规格单轧程产量可达555 t,规格比例达到60%以上,且带钢板形及表面质量满足品种开发和产品质量要求。     

基于遗传算法的冷连轧参数优化设计系统

以板形板厚为目标函数,利用改进的遗传优化算法,开发出四机架冷连轧机轧制参数优化设计系统,对原轧制规程进行了优化设计。按新轧制规程生产的冷连轧成品带钢质量获得改善,并提高了轧机的轧制效能。     

Suspension and solution thermal spray coatings

The emerging methods of coating deposition by suspension and solution thermal spraying are described. The liquid suspensions of fine powders and liquid precursors are injected into flames and/or jets generated in the torches. The formulation and stability of suspensions as well as the methods of fine powders synthesis are briefly described. Typical solutions, being often the liquid organo-metallics are also briefly described. An important problem of injection of liquids into jets and flames is then presented. Two principal modes of injection, used at present, are outlined, i.e.: (i) atomization; and, (ii) injection of a continuous jet. Subsequently, the phenomena occurring in flames and plasma jets are discussed and the major differences to these occurring during conventional spraying are stressed up. The build up of coatings starting from the impact of fine particles on the substrate is described and typical microstructures of suspension and solution sprayed coatings are shown. Some properties of the sprayed coatings, including mechanical, electrical, chemical, and thermophysical ones are collected and presented. Finally, the emerging applications of coatings are shown and the possible future applications are discussed.     

A 3-D modular fixture with enhanced localization accuracy and immobilization capability

Modular fixtures are distinguished for their high flexibility. Previous researches focused on 2-D objects or 3-D objects with regular geometry. This paper introduces our systematic study of 3-D modular fixtures, particularly for complex objects. For the sake of both function and simplicity, three baseplates are arranged equilaterally. One baseplate is fixed horizontally, on which three fixels are installed to support the object. The other baseplates are moveable and at least one fixel is set on either of them. Totally, seven fixels are adopted. Efficient algorithms are presented for computing optimal fixel locations for the given object pose regarding localization accuracy and immobilization capability. On account of the manufacturing errors, measuring and adjusting techniques are developed to improve the localization accuracy. Case studies are investigated to illustrate applications. Experiments are performed for verifying the principles, including the well-known theoretical proposition that seven fixels are necessary and sufficient for fixturing a 3-D object of nonrevolutionary surface.     

镁合金抗氧化及合金化阻燃研究进展

综述了镁合金氧化燃烧及燃点的测定方法、镁合金抗氧化和阻燃机理及合金元素(Ca，Be，RE，Y)对镁合金阻燃性能影响的研究现状。介绍了抗氧化和阻燃镁合金研制进展及应用现状，指出了研究中存在的问题及发展方向。     

平板类气体辅助注射成型产品的CAE模拟研究

通过建立具有代表性的平板类气体辅助注射成型产品模型,借助注塑成型CAE软件Moldflow对该模型进行了一系列分析模拟。通过对模拟结果数据的综合分析和数学处理,得到了气体注射参数对气道穿透长度的影响规律、气体注射参数设置及气道穿透长度预测公式。     

超声电镀锡铋合金研究

研究了超声波对锡铋合金电镀的影响.通过赫尔槽试验优选出最佳镀液配方和工艺条件,用SEM法观测了镀层形貌,并测试了镀层和镀液性能.结果表明:超声波的作用扩大了电流密度范围和温度范围;所得镀层表面光亮、结晶更细致、均匀,镀层结合力、抗氧化性和可焊性改善明显,耐蚀性增强;镀液性能稳定,阴极电流效率和沉积速度得到提高.因此,超声波对电镀工艺条件、镀层质量和镀液性能都有明显的改善作用.     

Rupture locations of friction stir welded joints of AA2017-T351 and AA6061-T6 aluminum alloys

The tensile rupture locations of friction stir welded joints of AA2017-T351 and AA6061-T6 aluminum alloys were examined. The experiments show that the rupture locations of the joints are different for the two aluminum alloys, which are influenced by the welding parameters. When the joints are free of welding defects, the AA2017-T351 joints are ruptured in the weld nugget adjacent to the thermo-mechanically affected zone on the advancing side and the rupture surfaces appear as oval contours of the weld nugget, while the AA6061-T6 joints are ruptured in the heat affected zone on the retreating side and the rupture surfaces are inclined at a certain degree to the bottom surfaces of the joints. When welding defects are present in the joints, the AA2017-T351 joints are ruptured in the weld center, while the AA6061-T6 joints are ruptured on the retreating side near the weld center. The rupture locations of the joints are dependent on the internal structures of the joints and can be explained through them.     

An ab initio study of Ti-Y-O nanocluster energetics in nanostructured ferritic alloys

So-called oxide dispersion strengthened steels or nanostructured ferritic alloys (NFAs) contain nanoprecipitates which give them exceptional mechanical properties and resistance to radiation effects. However, the structure and composition of these nanoprecipitates are still uncertain. To help clarify the nature of the smallest nanoprecipitates, density functional theory calculations are used to investigate the most stable Ti, Y, and O nanocluster computational units in Fe. Two distinct methods for searching for stable nanoclusters are proposed: one in which nanoclusters are restricted to the body-centered cubic Fe lattice and one in which the nanocluster structures are strained variants of bulk Ti and Y oxides. We discovered that nanoclusters that are structurally similar to bulk Ti and Y oxides are significantly more stable than nanoclusters that are restricted to the Fe lattice. Consequently, the most stable nanoprecipitates in Ti-Y-O NFAs are more likely to be small oxide phases than coherent solute-enriched clusters.     

院校研究的基本范式:定性模式与定量模式

院校研究有两种研究路向,一种是“(问题)一理论—假设—观察一理论一(问题)”的研究路径,另一种是“(问题)一观察一概括一理论—观察一(问题)”的研究路径。从哲学方法论层面看,院校研究主要有四种研究范式,即经验主义、实证主义、结构主义和人本主义。其中,实证主义和经验主义是定量研究的方法论基础,结构主义与人本主义是定性研究的方法论基础。定性研究与定量研究并不是绝对的两分,它们构成一个连续的系谱。实验法与文学法位于这一系谱的两个极端。     

钢结硬质合金材料的研究进展

介绍了钢结硬质合金的性能特点及制备工艺,简述了近年来在钢结硬质合金领域开展的研究与取得的进展,对钢结硬质合金的应用进行了分类归纳,展望了其发展前景。     

电弧传感器的研究现状与展望

电弧传感器作为一种实时传感的器件,与其它类传感器相比,具有结构简单、成本低以及跟踪灵敏度高等特点,焊接时不需要附加设备.详细综述了电弧传感器的分类、焊接工艺性能、电弧传感器的数学模型以及电弧传感器技术的研究及应用状况,并对今后的电弧传感器的发展前景作了展望.