轧钢加热炉改造

针对轧钢加热炉加热能力不足,炉墙冒火,自动化控制水平落后的情况,对加热炉进行了改造,延长了加热炉的长度,更换了单蓄热式空气烧嘴,并对自动控制系统进行了升级改造,从而消除了炉墙冒火的现象,提高了加热能力和自动控制水平,降低了煤气消耗,取得了良好的经济效益。     

TRT顶压控制系统及其安全性的研究与优化

介绍了天钢1~#TRT顶压控制系统,对现有的顶压控制系统进行了分析,在原有差压调节模式的基础上增加了顶压调节模式,将实际操作改为差压调节与顶压调节两种互选模式,提高了系统的发电效率;对旁通阀组的控制进行了优化,优化后极大地提高了系统的安全性,保证了炉顶压力的稳定,延长了设备的使用寿命,产生了较高的经济效益。     

变频器在4#空分油泵控制系统上的应用

叙述了天铁动力厂4#空分系统辅助油泵应用EV2000变频器控制系统的过程,对运行中出现的溢油、油压波动不稳等故障现象原因进行了分析,提出了改进方案.改进后消除了故障现象,实现了闭环控制油泵的转速和启停,减小了对电机和电网的冲击和振动,提高了设备的可靠性,延长了电机使用寿命,保障了生产的顺利进行.     

提高转炉护炉效果的实践

从转炉耐材的损害机理入手,分析了耐材的损耗机理,探讨了炉渣的优化机制,对炉渣的组成及渣料的使用进行优化,对溅渣的工艺进行了改进,实现了转炉护炉的提升,延长了转炉的使用寿命,降低了耐材的损耗,降低了转炉工序的成本。     

废水处理站自动控制系统的应用

介绍了邯钢冷轧废水站的配套项目废水处理站的自动控制系统,主要从自控设备组成、网络控制系统等方面论述了控制功能的实现,该系统的应用为ERP的数据采集提供了很好的保证,提高了电气控制的集成度和可靠性,简化了控制环节,提高了生产效率.     

浅议矿脉变化规律与探矿方法

概要介绍了樟东坑矿区的主要地质特征,在前人工作的基础上,对矿床的基本特征(尤其是矿脉的变化特征)进行了分析、探讨和总结;利用这些特性及其变化规律,采用一些新的探矿方法不但找到了一些隐伏盲矿,增加了地质储量,延长了矿山的服务年限,而且降低了探矿费用,减少了采矿的盲目性,节约了成本,增加了经济效益。     

钻探施工方案优化实践

在矿区钻探工程施工过程中,针对钻探工程的特点及现场施工条件,对受影响的原设计方案进行了优化,全面综合分析考虑,充分利用了一切可以利用的手段和措施,提高了工程的实用性、安全性,降低了工程成本。进一步升华了钻探方案,提高了工程质量,最大程度的减少了工程施工的风险与难度,实现了企业利益最大化,同时保证企业的投资决策质量和经济效益达到了双赢。     

用友资产管理系统在设备管理上的应用

用友资产管理系统根据天铁集团的设备管理要求配置了相关的功能模块,实现了设备管理的精细化、科学化、信息化,提高了设备的管理水平,降低了设备维修费用,同时实现了与财务一体化的无缝对接,为相关的钢铁企业设备管理信息化工作提供了参考。     

朱店尾矿坝隐患治理研究

通过对尾矿库存在的隐患分析,找出原因,并对选场工艺及水系统进行了改造,改善了尾矿库的状态,消除了隐患,降低了成本,稳定了选矿指标。     

ACS6000SD变频器在粗轧机主传动系统中的应用

济钢中厚板厂3500线粗轧机改造主传动系统采用ACS6000SD变频驱动系统,系统的整流侧和逆变侧采用了对称结构,降低了维护难度;采用了IGCT技术,保证了系统的性能响应;使用了DTC技术,提高了系统的鲁棒性。这种交直交系统做到了对电网的最少谐波运行,既减少了对电网的污染,又省去了无功补偿系统的投资。     

戈塘金矿房柱法开采围岩稳定性分析

戈塘金矿矿体厚度变化较大,地质条件复杂。为科学设计井下采场参数,分析采空区顶板的破坏机理及矿柱的承载机理,指导矿山安全生产,以戈塘金矿为研究对象,设计了采场参数,分析了采场围岩稳定性。通过理论计算,采用房柱法开采时,推荐矿柱尺寸为3 m×3 m,矿房跨度不超过10 m;利用有限元软件Phase2对留设不同宽高比的矿柱时采场围岩的稳定性进行了数值模拟分析。结果显示:矿柱内部出现应力集中,采空区顶底板、岩帮为应力降低区域;随着矿柱宽高比的增大,采空区边界附近的应力水平和位移降低,矿柱内应力集中得到缓解,变形量降低。综合分析认为,矿柱宽高比对采场围岩稳定性有一定影响,保持矿柱宽高比约为0.500,可以较好地维持采场稳定。     

等温压缩对高强度汽车钢WHT1300HF的马氏体相变及微观组织的影响

通过等温形变研究了形变参数(形变温度、形变速率、形变量)对高强度汽车钢WHT1300HF的微观组织转变和形貌的影响规律。研究结果表明:增加奥氏体等温形变量,有利于铁素体的缺陷形核,促进了形变奥氏体向铁素体转变;奥氏体的形变强化导致马氏体相变阻力增大,马氏体相变开始温度(Ms)下降,细小晶粒数量和小角度晶界数量增多;增加奥氏体等温形变(40%)速率能同时促进马氏体和铁素体相变,但马氏体体积分数和小角度晶界数量减少,细小晶粒数量略有提高;降低等温形变温度加剧奥氏体的形变强化,导致Ms温度下降,马氏体体积分数、小角度晶界比例减少,细小晶粒数量增多,铁素体含量明显增加。     

Dermomyotomal origin of the ribs as revealed by extirpation and transplantation experiments in chick and quail embryos

To elucidate role of the dermomyotome in the formation of the axial skeleton, we performed extirpation and transplantation experiments on the dermomyotomes in chick and quail embryos. When the thoracic dermomyotomes of chick embryos were removed, the intercostal muscles and the distal ribs were deficient, while the proximal ribs were more or less normal. Quail tissues including the dermomyotome, the ectoderm and the medial edge of lateral plate, were transplanted to replace chick dermomyotomes. In these chimeras, the ribs, which would be deficient without the back-transplantation, were recovered. The cells of the recovered part of the ribs as well as the intercostal muscles were derived from the quail transplants. These findings suggest that the distal rib originated from the dermomyotomes and not the sclerotome as previously believed. To localize the origin of the distal rib further, we removed restricted regions of the dermomyotomes along the mediolateral and the rostrocaudal axis. The more lateral the part of the dermomyotomes that we removed, the more distal the part of the ribs affected. On the contrary, when the rostral and caudal edges of the dermomyotomes were removed, only the vertebral ribs showed extensive deficiencies while removal of the middle part between the edges caused less deficiency. The sternal ribs were not deficient in either case, but were extensively affected when the entire lateral edge of dermomyotomes was included in the region removed. We conclude that the lateral edges of the dermomyotomes are the primordia of the sternal ribs, and the rostral and/or caudal edges of the medial part of dermomyotomes are the primordia of the distal part and not of the proximal part of the vertebral ribs.     

A method of estimating linear and angular accelerations in head impacts to pedestrians

In order to investigate the relationship between impact to the head and brain injury, we have developed a method, using information obtained from reconstruction of the collisions, of estimating the peak linear and angular accelerations of the head for pedestrian impacts on a vehicle. This information includes the location of the impact on the head, the impact velocity of the head, and the stiffness of the struck surface. In developing the method we assumed that the velocity of the head on striking the vehicle was the same as the velocity of the vehicle itself, that the force vector was normal to the surface of the skull, that the force-deflection curve characterising the combined response of the impacted surfaces was linear, and that the kinetic energy of the head immediately prior to impact was converted into strain energy in deforming the head and the vehicle structure. Only the loading phase of the impact was considered, there was no assumption of an elastic unloading phase. Using cadavers, the validity of these assumptions and hence the usefulness of the method were tested by comparing the estimates of peak linear acceleration with the results of 18 pedestrian-vehicle impact reconstructions. On average, the method underestimated the experimental values by about 15%, with a range of +/- 35%. The results from the application of this method are currently being used to study the relationship between the magnitude and direction of the impact to the head and the distribution and severity of the brain injury resulting from actual collisions.     

高端装备用轴承钢冶金质量性能现状及未来发展方向

针对滚动轴承特点、轴承钢类型以及国内外轴承钢差距,本文对国内外高端装备用轴承需求、国内外轴承钢品种、轴承钢生产装备与冶金质量、轴承钢热处理技术以及轴承钢质量性能评价技术等发展现状进行了综述,指出了国内外高端装备用轴承钢在冶炼流程的超纯净控制、新型热处理技术和新型轴承钢研发对提升轴承长寿命的巨大作用,提出了未来基于夹杂物、碳化物和基体组织细质化、均匀化和稳定化的传统轴承钢质量性能提升、髙性能热处理研发、新型轴承钢材料创新以及加强抗疲劳基础理论研究的发展方向和大幅度提升轴承钢接触疲劳寿命的发展目标。     

浅谈后张法有粘结预应力梁施工工艺

本文旨在更有效地利用高强钢材,弥补混凝土与钢筋拉应变之间的差距,把预应力运用到钢筋混凝土结构中去。亦即在外荷载作用到构件上之前,预选建立有内应力的混凝土,通过对预应力筋进行张拉、锚固、放松,借助钢筋的弹性回缩,使受拉区混凝土事先获得预压应力。当构件承受由外荷载产生的拉力时,首先抵消混凝土中已有的预压力,然后随荷载增加,才能使混凝土受拉而后出现裂缝,因而延迟了构件裂缝的出现和开展。     

轧辊非均质特性对辊型电磁调控的影响分析

 轧辊作为辊型电磁调控技术的核心构件，在加工制造时必须进行热处理，改变轧辊表层组织形态，形成轧辊表面淬硬层，引起轧辊表层和芯部材料性能差异,而这种差异会对辊型电磁调控特性产生影响。为此，利用有限元软件MSC.MARC建立了电磁 热 力耦合轴对称模型，并依托辊型电磁调控试验平台对模型精度进行校核。在此基础上，依托模型分析了表面淬硬层厚度对辊型电磁过程中辊凸度、辊型曲线、接触面平均正压力及轧辊应力分布的影响。结果表明，表面淬硬层厚度对辊凸度、辊型曲线和接触面正压力的影响较小，但对轧辊应力分布有明显影响，特别是轧辊表面淬硬层中心区域。     

Multiple-cracking phenomenon of the galvannealed coating layer on steels under thermal and tensile stresses

The multiple-cracking phenomenon of the Fe-Zn intermetallic coating layer on the hot-dip galvannealed (GA) steels under thermal and tensile stresses was studied experimentally by tensile tests and analytically by means of the finite-element analysis. The multiple cracking of the coating layer had occurred in the as-supplied samples, and it progressed with increasing applied strain. Based on the calculated dependence of the stress of the coating layer on the crack spacing and applied strain, the multiple cracking in the as-supplied samples was accounted for by the thermally induced residual stress, and the further multiple cracking with increasing applied strain was accounted for by the increased stress of the coating layer. The experimentally observed decrease of the average crack spacing with increasing applied strain was described well, and the tensile strength of the coating layer was estimated to be 260 MPa, by application of the calculated relation between the increased stress of the coating layer and applied strain. The influences of the thickness of the coating layer and the substrate material on the multiple cracking were discussed based the stress analysis. It was revealed that the thinner the coating layer and the higher the flow stress of the substrate, the higher the stress of the coating layer becomes and, therefore, the smaller the crack spacing becomes.     

Diagnostic Analysis of the Evolution Mechanism for a Vortex over the Tibetan Plateau in June 2008

Based on the final analyses data (FNL) of the Global Forecasting System of the NCEP and the observational radiosonde data,the evolution mechanism of an eastward-moving low-level vortex over the Tibetan Plateau in June 2008 was analyzed.The results show that the formation of the vortex was related to the convergence between the northwesterly over the central Tibetan Plateau from the westerly zone and the southerly from the Bay of Bengal at 500 hPa,and also to the divergence associated with the entrance region of the upper westerly jet at 200 hPa.Their dynamic effects were favorable for ascending motion and forming the vortex over the Tibetan Plateau.Furthermore,the effect of the atmospheric heat source (Q1) is discussed based on a transformed potential vorticity (PV) tendency equation.By calculating the PV budgets,we showed that Q1 had a great influence on the intensity and moving direction of the vortex.In the developing stage of the vortex,the heating of the vertically integrated Q1 was centered to the east of the vortex center at 500 hPa,increasing PV tendency to the east of the vortex.As a result,the vortex strengthened and moved eastward through the vertically uneven distribution of Q1.In the decaying stage,the horizontally uneven heating of Q1 at 500 hPa weakened the vortex through causing the vortex tubes around the vortex to slant and redistributing the vertical vorticity field.     

Nature of the curves of the cranial vault and their relationship with various brain structures

A radiometric investigation for various angles of two dry craniums and of the encephalographic or cerebral arteriographic pictures of 250 subjects has revealed the following facts: The architectural lines of the dome of the skull found by orthogonal projection of the profile, from the front, and in vertical projection, are hyperbolic spirals starting from the base of the skull and converging on the sphenoid. These lines join up in the parietal region forming a hyperbole. The frontal spiral is a simple hyperbolic spiral. The temporal spiral is of the lituus type. The axes of these lines converge in a frontal plane on the epiphysis. The axis of the parietal hyperbole on a projection of the profile passes through the epiphysis and is followed by the parietal artery. Central cranio-encephalic formations follow the same spiral path. The contour of the upper edge of the cerebellum is a lituus spiral. The outline of the lower part of the cerebellum is a simple hyperbolic spiral. The right side of the polar origins of a spiral plotted in the plane of the insula coincides with the right side of the opercula. It can always be plotted, in theory, and forms an angle of 22 degrees 30' with the right side of the median frontal spiral. It cuts the axis of the parietal hyperbole at the apex of the insular triange. The bissector of the angle formed by the two right sides of the polar origins bissects the axis of the parietal hyperbole at a point corresponding to the epiphysis. The temporal hyperbolic lituus spiral has its focal point under the anterior, clinoid, at the junction of the segments CII and CIII of the carotid siphon the curve of which follows the convolutions of the temporal spiral. The right side of the polar origins of this curve indicates the mean direction of the posterior cerebral. The contours of the corpus callosum are homothetic with those of the dome of the skull as far as the axis of the parietal hyperbole. The frontal and parietal curves converge according to four types in the main Pacchionian granulations. The sections of the frontal spiral are often marked by bone abnormalities on the internal table. This analytic test is invariably valid whatever the constants of the spirals or the eccentricities of the hyperboles. Combinations between spirals with different constants and hyperboles of various eccentricities amount to very many types which call for separate study.