表面预处理和润滑条件对硫氮共渗35CrMo磨损性能的影响

目的提高35CrMo钻杆接头和对磨套管的耐磨性能。方法采用超声表面加工处理和硫氮共渗处理技术对钻杆接头常用的35CrMo钢进行处理,研究了超声表面预处理和润滑条件对其耐磨性能的影响。利用光学三维形貌仪、扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)分别研究了试样的表面形貌、粗糙度、成分和相结构,采用环块磨损试验机在油基钻井液润滑和无钻井液润滑的条件下,考察了经过不同载荷超声表面加工预处理的35CrMo钻杆接头及其对磨套管的磨损性能。结果超声表面加工预处理可使35CrMo钢及其硫氮共渗处理后的表面粗糙度显著降低约80%以上。经超声表面加工预处理后,35CrMo钢硫氮共渗钻杆接头在油基钻井液润滑和干摩擦条件下的磨损率均进一步降低。在无钻井液润滑的条件下,500 N载荷超声表面加工预处理后,硫氮共渗35CrMo钢钻杆接头对磨油管磨损表面形貌的改善更显著,表面粘着和犁沟均减少。结论 35CrMo钢钻杆接头在硫氮共渗前采用超声表面加工进行预处理,可以获得更低的表面粗糙度和更高的表面硬度,在有无钻井液润滑条件下均可提高钻杆接头和套管的耐磨性能。     

Influence of Metallurgical Conditions on the Lining Wear in the Kaldo Process

The influence of different metallurgical conditions on the lining wear in the Kaldo process when refining high phosphorus iron has been systematically investigated revealing the following main featuresThe lining is protected by a lime-saturated layer of slag during the main part of the first blowing period.The lining wear starts in connection with the melting of this protective layer which occurs at the end of the first period. After that, the wear rate increases rapidly.The rapid increase of the lining wear is caused by direct combustion in a strongly oxidizing atmosphere of liquid iron which has been dragged up on the lining surface.By decreasing the oxygen activity in the furnace atmosphere at the end of the oxygen-blowing period the wear can be decreased considerably. In practice this has been solved by directing the oxygen jet with high impulse steeply into the bath during this period of the blowing. In this way the lining life in Domnarvet’s 30 ton Kaldo furnace has been increased by about 75% without reducing the steel yield. Blowing time and consumption of oxygen have at the same time decreased by about 10%.     

射砂过程初始条件的试验研究

砂芯通常是用射砂的方法来制造的。随着计算机技术以及流体力学理论的发展,使得对射砂过程进行数值模拟成为可能。对射砂过程进行数值模拟时,芯盒入口处的砂流和气流的速度是必不可少的初始条件之一。本文利用高速摄影的方法,对射砂过程的初始条件进行了研究,得到了砂流在射入芯盒时的初速度。根据空气动力学原理,利用皮托管测量了芯盒入口处的气流速度。结果表明,射砂孔位置的气流和砂流速度有显著差别。本文的研究结果为准确     

工艺条件对激冷球铁凸轮轴材料的影响

介绍了激冷球铁凸轮轴的熔炼工艺及技术要求,研究了冷铁、原铁液过冷度、浇注温度、浇注速度、浇注系统对激冷球铁凸轮轴组织和硬度的影响。最终得出结论:(1)采用与单片凸轮质量之比为3倍的冷铁,对激冷球铁凸轮轴是较为适宜的;(2)只要化学成分相同,炉料配比、炉前过热温度和过热时间对激冷球铁凸轮轴材料并无大的影响;(3)在不产生气孔、冷隔等铸造缺陷条件下,采用尽可能低的浇注温度,有利于激冷球铁凸轮轴的材料性能;(4)在不出现气孔、砂眼等铸造缺陷条件下,尽可能缩短充型时间,可提高凸轮平均硬度,且同一凸轮轴的12个凸轮硬度均匀性提高;(5)减小紊流,防止冷铁被冒口预热,可解决凸轮轴部分凸轮硬度偏低的问题。     

高纯度氰化银生产工艺条件研究

高纯度氰化银是镀银工艺中重要的基础材料.以硝酸银/氰化钾(摩尔比)=1/1.05原料配比,采用硝酸银溶液滴加到氰化钾溶液中的加料方式,研究了搅拌速度、滴加速度、反应温度、脱水洗涤和干燥条件等工艺参数对氰化银生产的影响,得到了高纯度氰化银的最佳工艺条件.生产实践表明,上述工艺所得的氰化银纯度高,色泽和晶形完美,适用于大部分需要高纯度氰化银的镀银工艺.     

不同边界条件下消失模铸造泡沫珠粒射料充填数值模拟研究

建立了欧拉/拉格朗日离散颗粒模型,采用数值模拟方法,研究消失模铸造泡沫珠粒射料充填过程中稠密气固两相流动的流体动力特性.对每个颗粒进行编号追踪,后处理采用不同的颜色分布显示颗粒的编号区段,在不同边界条件下研究射料充填过程中颗粒的分布位置并进行对比,表明该方法可以有效地模拟射料充填过程中泡沫珠粒的运动.     

Experimental Planning for Rapid Determination Of Optimum Process Conditions

Fractional replication of factorial design, a general method for planning experimentation and for analysis of data obtained, is described as applied to a flotation investigation. This method leads to determination of optimum process conditions with minimum experimental effort. Its advantages over simple factorial design are demonstrated.     

基于高强度钢切削加工的切削力和扭矩对比试验

本文对高强度钢的切削加工性能进行了分析，通过试验总结了普通麻花钻切削高强度钢时的磨损、破损特点，并对普通麻花钻和基本型群钻进行了切削对比试验，证明群钻可使切削力和扭矩减小，使刀具耐用度提高。从而为高强度钢的切削加工提供了理论依据。     

工况条件对铜包钢线滑动拉拔过程的影响

讨论了变形量，拉拔速度，模具压缩角和润滑剂对铜包钢线滑动拉拔过程的影响，结果表明：变表量和拉拔速度越大，铜包钢线的加工硬化效应越明显，合适的模具压缩角和润滑剂有利于铜包钢线滑动拉拔过程的良好进行。     

Observations on the Influence of Tool-Sheet Contact Conditions on an Incremental Forming Process

The influence of tool-sheet contact conditions on features such as surface roughness, forming force, and formability was evaluated for components produced by incremental forming, a highly flexible innovative sheet metal-forming process. Experimental tests were carried out on sheets of AA7075T0 to create two types of component: pyramid frusta (for the evaluation of roughness and force) and cone frusta (for the evaluation of formability). Four different types of tool-sheet contact were analyzed, using two types of tool. From the experimental tests, the influence on the surface finishing and on the trend of the forming forces depending on contact type was revealed. Contact types do not, however, influence sheet formability.     

电沉积方法制备纳米晶Ni-W合金工艺研究

为了进一步优化镀液成分和工艺参数,为制备W含量可在较大范围内变化的块状纳米晶Ni-W合金提供依据,采用不含任何氨根离子(NH-+4)的镀液通过电沉积方法制备纳米晶Ni-W合金镀层.采用XRD、SEM和EDS对镀层的结构、形貌和成分进行观察和分析.结果表明:电沉积过程中电流密度、电源类型、pH值及搅拌方式对镀层的W含量都会产生较大的影响.试验中所得到的Ni-W合金镀层的W含量为2.15%~30.31%(质量分数),其结构均为W溶于Ni晶格所形成的置换式固溶体,平均晶粒尺寸为14~19nm;随着镀层中W含量的增加,镀层的显微硬度也随之逐渐提高.     

冷却条件对铜镍合金凝固行为的影响

为研究冷却条件对铜镍合金铸件质量的影响,在对铜镍合金铸造工艺分析的基础上,引用传热-流动一应力耦合的铸造模拟软件PROCAST对不同的冷却条件下铜镍合金的凝固进行缺陷和温度场分布数值模拟,并根据模拟结果,结合实验分析了不同冷却条件下铸件质量,确定了铜镍合金凝固过程中较为合理的冷却条件.提高了铸件质量.模拟结果表明:在钢模加保温冒口浇铸条件下,铜镍合金铸件的质量最佳.     

Optimization of Set-up Conditions for Stability of The Centerless Grinding Process

The stability of the centerless grinding process is very sensitive to the set-up conditions due to the uniqueness of the work-holding system. Centerless grinding produces precision components with high productivity only when the set-up condition is optimally chosen. This paper describes the effect of set-up conditions on three stability criteria of the centerless grinding system. It also presents guidelines for determining proper set-up conditions to avoid spinners, chatter vibration and roundness problems. Finally, an algorithm for providing the optimum set-up condition based on process aims is proposed and the simulation results are discussed.     

工艺条件对YBCO厚膜基带晶粒取向的影响

用Ｘ射线方法研究了平行于基带表面的Ｎｉ（２０Ｏ），Ｎｉ（１１１），ＮｉＯ（２００）和ＮｉＯ（１１１）晶面的取向分数Ｗ。结果表明，随预热处理温度的提高，虽然Ｗ_（ＮｉＯ（２００））也会随之提高，但是区域重加热处理对提高Ｗ_（ＮｉＯ（２００））起着最重要的作用。９００℃预热处理之后，在１１００℃进行区域重加热可使Ｗ_（ＮｉＯ（２００））提高到０．９９以上。     

工艺条件对碳钢表面化学镀Ni-P质量的影响

碳钢在工业中有着非常广泛的应用,但耐腐蚀性能欠佳使其应用受到了一定的限制,而化学镀就是提高碳钢耐腐蚀性的一种重要方法。以碳钢为基底进行酸性化学镀镍磷工艺的研究,考察了工艺条件温度、pH值对碳钢化学镀镍层沉积速率及腐蚀速率的影响,并通过扫描电镜和能谱分析对镀层的形貌及成分作了分析研究。结果发现,碳钢化学镀镍最佳工艺条件为：pH值4．5～5．2,温度在70℃左右。在该工艺条件下对碳钢表面进行化学镀镍,可获得光亮、细致、均匀、附着力强、耐蚀性好的镀层。由镀层成分分析可知,镀层中Ni质量分数为87．53％,P为9．26％。     

调谐支架注射模设计

根据调谐支架塑件的结构特点,合理地选择了注射模的分型面,优化设计了模具的整体结构。在采用侧向分型抽芯机构时,将2个塑件的侧型芯固定于同一滑块上,使模具的整体结构更加紧凑。经塑件的批量生产验证,该模具成型工艺过程稳定可靠,生产的塑件质量好。     

Tuning the Properties of Nanocrystalline CdS Thin Films

Tuning the properties of nanocrystalline cadmium sulfide (CdS) thin films is very important in the technology of photonics, detectors, and computing devices. This can be achieved through the appropriate selection of the synthesis techniques, types and concentrations of the chemicals, deposition parameters, and postdeposition heat treatments. In addition, control of the properties can be achieved by controlling the size, structure type, and surface states of the nanocrystallites without altering the chemical composition of the films. A review of the experimental methods for tuning the properties of nanocrystalline CdS thin films is performed. Although control of these variables is a complicated process, high-quality nanocrystalline CdS thin films with optimum structural, morphological, and optical properties have been produced by different authors.     

过流冷却体工艺条件对亚共晶高铬铸铁组织的影响

采用过流冷却体法制备亚共晶高铬铸铁,研究过流冷却体工艺条件对亚共晶高铬铸铁组织的影响。结果表明,采用过流冷却体法制备的组织与常规凝固组织相比圆整度较高、尺寸较小;过流冷却体长度、角度、凹槽半径对亚共晶高铬铸铁初生奥氏体的形貌影响均很明显。随着过流冷却体长度、角度的增大,初生奥氏体的圆整度先提高后降低,尺寸先减小后增大。大凹槽半径的过流冷却体制备的初生奥氏体较小凹槽半径过流冷却体制备的初生奥氏体圆整、细小。